Erection Procedure For 415 V LCC, LDBS, LPS, SP

EP/LT PANEL/REL/KAIGA 3&4 / 014 PAGE
ERECTION PROCEDURE FOR 415 V SWITCH GEAR .
1. SCOPE:
This procedure covers the guidelines for CL-II , CL-III & CL-IV 415V Switch Gear
handling and installation for all applicable areas of KAIGA 3&4 electrical package.
2. PURPOSE:
The purpose of this procedure is to provide guidelines for handling and installation
of CL-II , CL-III & CL-IV 415 V Switch Gear in all areas of plant. The Detailed
commissioning procedure shall be separately prepared.
3. APPLICABILITY:
This procedure is applicable for the CL-II , CL-III & CL-IV 415 V Switch Gear used at
KAIGA 3&4, Electrical package .
4. REFERENCE DOCUMENTS:
1) Module specifications PP-E-1754 ( E-6 )

2) Applicable codes and specifications .
2) Equipment layout drawings .
3) Manufacturers scheme drawings & dimensional drawing of Panels .
4) Manufacturers instruction for erection activities .
5. RESPONSIBILITY:
Responsibility of implementation of this procedure lies with the Site In Charge.
6. PREREQUISITES:
a) Approved drawings shall be available for erection of 415 V Switch Gear .

b) Get area clearance for equipment erection .
c) The civil works like embedded parts / Foundation for panels shall be checked with
approved drawings .
d) Required no. of Panels / Bus Ducts shall be available at site .
e) Route and feasibility of panel shifting and lifting shall be surveyed thoroughly
f) Rubber mats of 415V voltage grade are available and provided as per layout before
energisation/testing of panel.
Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

g) Ensure that proper security arrangement / lockable door is provided before

Energisation .
h) Proper Ventilation and illumination shall be available during the time of erection and
other activities .
i) Fire fighting system is in place
j) Qualified manpower for erection shall be employed
k) Approved procedure for welding and structural steel fabrication & erection shall be
followed .
l) Welding consumables shall be of approved make .
m) Calibrated instruments and testing equipments shall be made available
n) Use of tested lifting/handling tools and tackles shall be ensured
o) Shipping Release note along with Material receipt intimation cum acceptance report.
p) Availability of required storage area shall be ascertained .
7. EQUIPMENT & ACCESSORIES:
a) Rolling pipes / Rollers

b) Crow bars
c) Electrician tools
d) Spanner sets
e) Welding machine
f) Slings and ropes as per requirement
g) 1000 V & 500 V meggars
h) Torque wrench
i) Crane and vehicle for equipment shifting.
8. PROCEDURE
8.1 SHIFTING OF MATERIALS FROM STORAGE YARD TO ERECTION SPOT

a) Load the panel / Bus Duct in truck from storage yard using a mobile crane / fork lift /
Manually ( If weights of panel can be handled manually )
b) Ensure correct panel / Bus Duct is received from the stores and it is being taken to
its correct destination at site .
c) After loading the transportation unit of Switch Gear / Bus Duct on the truck, tie them
to sides of truck firmly by rope .
d) After reaching the point nearest to erection spot, unload the transportation unit of the
Switch Gear / Bus Duct .
e) Verify the route from unloading spot to erection spot for free access .

f) For Switch Gear / Bus Duct to be installed at higher elevations shift them from
unloading spot to higher elevation by using a crane / Suitable methods through the
openings planned in the building for the purpose .
g) Shift the panels / Bus Ducts by putting skid rollers / Rolling Pipes under the bottom
wooden pallet & pushing the panel manually up to the erection spot. Ensure that the
panels / Bus Duct are not given any undue jerks. Also ensure the safety of working
personnel is as per the approved safety procedures.
h) If the panels / Bus Duct weight are less and shall be manually handled , then it shall
be moved to the erection spot from the truck / Vehicle with proper manpower .
8.2 BASEFRAME ERECTION ON EP"S GROUTED IN THE FLOOR
a) Check the location, dimension, clearances as per the GA drawing .
b) Base channels shall be properly identified with respect to their particular panels
before installing in to their respective position .
c) The position of the base channel with respect to grid reference or wall shall be
checked .
d) Check the embedded plate (EP) for levelling with water level. Remove the paint from
base frame surface wherever it is to be welded to EP. Also clean the EP. The base
frames shall be placed over EP"S as per GA drawings .
e) The base frame shall be checked for levelling and alignment. If deviations are
observed it can be corrected with shims . Level difference of more than 2 mm is not
allowed .
f) After ensuring of alignment & leveling tack welding shall be carried out between
EP"s and Base frames . After tack welding of all base frame with EP"S check for
alignment & leveling .
g) After ensuring of alignment welding shall be carried out between base frame and
EP"S . Size of the fillet weld shall be 6 mm. Welding shall be carried out as per
approved welding procedure and as per enclosed drawing . ( Annexure –1 )
h) The length of welding and gaps between welding shall be decided as per Drawing
enclosed in Annexure -1 . ( Schneider to comment )
i) 10% of total weld length shall be subject to dye penetration testing .
j) After completion of welding , damage areas of painting in Base channel shall be
touched with primer and Enamel paint . Finish coat of base frame shall be black
enamel paint .

8.3 PANEL ERECTION

a) Unpack the transportation units of LT Switch Gear / Panels and remove the wooden
packing from sides and top except on the bottom side ( Base ) . Bottom pallet shall
be removed only when the switch gear nears to its location . Dispose the wood to its
allocated area. Check the nameplate details and for any physical damage.
b) Check the two diagonal distances of cubicle to ensure that frame is not damaged .
Difference between two diagonal distances should not be more than 6 mm .
c) Shift the Switch Gear / Panels on to the welded base frame. Shifting of panels shall
be done with Rollers / Pipes / Crow Bars . If crow bar is used , it shall be inserted
either on the side or rear of the cubicle for shifting .Crow bar never to be inserted in
front of the panels . Check for front view , Straightness , side alignment , levelling
and sequence (board number, breaker number etc.) of LT Switch Gear / Panels it
should match with the GA drawing .
d) Panels in sequence shall be erected one by one .
e) Fasten the adjacent LT Switch Gear / Panels with fasteners and accessories (loosely
supplied) as per the drawing .
f) Now check for alignment of panels . For Alignment , single panel shall be taken as
reference and remaining panels can be checked with respect to that by means of
water level / Plumb .Any deviations observed in the alignment shall be adjusted with
shims of proper size .
g) Verticality of panel shall be checked for all panels by means of plumb .
h) After ensuring for horizontality and verticality side coupler bolts shall be tightened
fully as per Manufacturers recommendation . Tolerance shall be of +/- 10%
( Schneider to comment )
i) Tack weld 415 V Switch Gear to base frame as per GA drawing at the start and end
of all panels at both front and rear sides .
j) Clean the contact surface of the phase, neutral and earth busbars at the sides of
each LT Switch Gear and apply electrical contact grease on their surface. Cleaning
of bus bar joints shall be done with stainless wire brush and by cleaning aids Acetone
/ Trichloroethylene and grease applied shall be of Pure Petroleum Jelly / Contact
Grease . Couple the bus bars of adjacent LT Switch Gear / Panels units with busbar
links and necessary hardware with proper alignment and clearance as per the
drawing.

k) Tighten all the bus bar joints, fasteners using torque wrench as per Manufacturer
Recommendation . . Tolerance shall be of +/- 10 N/M. ( Schneider to comment )
l) Now full welding of 3 mm between LT Switch Gear / Panels and Baseframe shall be
carried out. The length of welding and gaps between welding shall be as per
enclosed drawing . ( Schneider to comment – GA Drawing to be enclosed with
the welding details )
m) Ensure also that earth busbars are properly connected and tightened .Tightness of
bolts shall be as per Manufacturers recommendation .
n) Provide earthing to LT Switch Gear / Panels as per earthing scheme and drawings
o) Connect up the inter panel wiring between adjacent LT Switch Gear / Panels panel
as per the scheme drawing .
p) Install all loosely supplied meters, relays, instruments as per GA drawing .
q) After completion of all erection activities , Cleaning of insulators, bushings , busbar
joints etc shall be cleaned with Carbon tetra Chloride / Petrol .
r) Before packing ensure that proper shrouds are provided in all busbar joints .
s) IR Value of LT Switch Gear / Panels shall be done with 1 KV / 500 V Meggar as
per the enclosed format .
Recommended Meggar and Minimum IR values are as below:-
Voltage Meggar IR value (Min)
Upto 1000 V 1000 V 1 M. Ohm ( Schneider to comment )
If the test value is less than the above, arrange drying out for LT Switch Gear /
Panels.
t) After completion of all checks panels shall be cleaned fully by vaccum cleaner / Hot
blower .
u) Ensure for erection of Shrouds on Bus bar Joints & at Power Cable terminations .
8.4 POWER & CONTROL CABLE CONNECTION
Power Cables are to be connected in the cable compartment of the cubicle . A
removable gland plate is provided in the bottom sheet of cubicle which should be cut
to suit the power cable and the gland if used . Opening of the bottom plates if any ,
are to be blocked by using approved Compounds .

Control Cables are directly terminated in the low voltage apparatus compartment
through bottom gland plate .
8.5 PROCEDURE FOR CONDUCTING VARIOUS PRELIMINARY CHECKS ON

SWITCH GEAR / PANELS AND ITS COMPONENTS
A) Switch Gear Preliminary Checks :
1) Check name plate details of every associated equipment according to
specification.
2) Check for any physical damage .
3) Check for tightness of all bolts , clamps and connecting terminal.
4) Check for panel cleanliness
5) Check for cleanliness of insulators and bushings .
6) Check heaters are provided in all compartments.
B) Circuit Breaker preliminary checks:
1) Check name plate details according to specification .
3) Check tightness of all bolts , clamps and connecting terminals .
4) Check for proper earth connection.
5) Check cleanliness of insulators and bushings .
6) Check for all moving parts for proper lubrication .
7) Check for proper movement of breaker from with drawn position to test and
test to service and vice versa .
8) Check for proper engagement of secondary plug and socket .
9) Check for proper engagement of earthing contacts.
10) Check for proper engagement of tulip finger contacts with the cubicle contact
bolts .
11) Check alignment of breaker trucks for free movement inside the cubicle and
correct operation of shutters.
12) Check for interchangeability of Circuit breaker of same rating .
13) Check for free operation of doors for circuit breakers and its mechanical
interlock when breaker is kept in Service / Test / Isolated Position .

14) Perform manual closing , opening operation on CB. Check the slow closing
and opening operation of the CB. Confirm the operation of mechanical
operation indicators. Note down any deficiency observed.
C) Current Transformer and Potential Transformer Preliminary Checks :
1) Check name plate details according to specification
3) Check for cleanliness
4) Check for tightness of all bolts , clamps and connecting terminals .
5) Check earth connections .
6) Check for healthiness of HT fuses .
D) Meters Preliminary checks :
2) Check for any physical damages .
E) Relays Preliminary checks :
2) Check for any physical damages .
F) Switch Fuse Feeder Units :-
1) Check module door arrangement , Operation & Door interlock arrangement .
2) Check switch fuse unit function .
3) Check rating of fuses .
4) Check withdrawability of switch fuse unit .
5) Check the tightness of cable terminations
6) Check operation of indicating lamps
7) Check operation of micro switch
G. Door Interlocks :-
1. Check ( if any ) for Door opening after isolator / Breaker ON
2. Door for closing after isolator / Breaker ON
3. Defeat function
4. Check for door gaskets
5. Check for Door Alignment & Proper closing / Opening .
H. Bus Duct Preliminary Checks :
1) Check the name plate details as per the specifications
2) Check for any physical damage
3) Check for tightness of all bolts/clamps and connection terminals
4) Check for earthing of busducts as per drawing .

5) Check for cleanliness of busduct .

6) Check for insulation resistance of busduct .
7) Check the continuity of busbars from terminal equipment on one side to that
on the other side.
9. ACCEPTANCE CRITERIA:
a) Conformity to schedule, drawings & specifications and manufacturers instructions.
10. CHECK LIST
a) The following checks has to be done as per the Erection procedure. .

. Remaining checks for Pre Commissioning will be covered in Commissioning
procedure .
Sl.No. Procedure number Description

1. CH/REL/SWITCH GEAR / Installation of 41V switchgear
2. CH/REL/ SWITCH GEAR / Insulation resistance on
busbars for 415 Switch Gear.
3. CH/REL/ SWITCH GEAR / Insulation resistance test on
CB
4. CH/REL/ SWITCH GEAR / Physical check for clearance
between bus bars for 415 V
Switch Gear.
11. PRECAUTION:
a) Check the physical conditions of LT Switch Gear before shifting from stores.
b) Qualified workmen shall be used for shifting and erection of LT Switch Gear .
c) While transporting in the truck LT Switch Gear shall be tightened and wooden
packings shall be provided
d) Safe PP ropes of size 1" shall be used for shifting the LT Switch Gear .
e) Discharge the bus after conducting IR test with discharging rod connected to the
earth .
f) Ensure safety of operating and testing personnel while conducting IR test. Rubber
mats of LT grade should be provided along the panel as per drawing.
g) Do not over tighten the busbars above its specified torque value .
h) Do not use tools other than panel keys ( Such as screw driver etc ) for opening
doors.
i) Do not erect panel on uneven foundation as this will cause misalignment of horizontal
busbar at transport section .

j) Do not store panel in open and humid areas.

k) Do not send panels to storage area with out inspection of transport damage .
l) Do not leave doors / blank cut out if any in open condition .
12. RECORDS
a) Manufacturers test reports for LT Switch Gear shall be available

b) Erection checklist No. CH/REL/LT PANEL / to for LT Switch Gear .
c) Calibration certificate of testing instruments shall be available .
13. DISTRIBUTION
Will be distributed to
a) NPCIL Quality Control Dept
b) NPCIL Execution Dept
c) NPCIL Planning Dept.
d) NPCIL Field Engg.Dept.
Total No. Of copies to be distributed is 4 Nos.

8.1 RECEIPT OF PANELS & ACCESSORIES :
a) Panels and accessories received shall be checked with respect to packing list,
shipping release & test certificates .
b) Any severe damages observed in the consignment shall be brought to the notice of
transporter and supplier for immediate replacement .
c) Minor damages happened shall be repaired / replaced with the approval of
Manufacturer and Engineer In Charge.
8.1.1 Unloading of panel :
Panels shall be unloaded by means of Mobile Crane / Forklift or manually if the size
of the panel / accessories is with in the capacity of manual unloading .
A) Unloading of panel with Mobile crane / Fork lift :
I. Unload the panel with mobile crane/forklift from the truck .
II. Position the crane hook on top of transportation unit of the LT Switch Gear /
Panels .
III. Suspend the ropes from the hook and pass them under wooden pallet under the
bottom of transport unit of LT Switch Gear / Panels
IV. Lift the transport unit of the LT Switch Gear / Panels, check the balance, if
unbalanced, lower the panel, correct the imbalance & then lift the panel
V. Unload the panels in storage yard at specified/identified location
VI. Incase of usage of forklift , the transportation unit shall be brought near to switch gear
and shall be put down .Then the transport unit shall be moved to the storage area .
B) Manual Unloading :
If the size of the unit / accessories is with in the capacity for manual unloading then
following procedure shall be followed
I. The truck Vehicle shall be brought to the desired location.
II. Tripods / devices with chain pulley shall be used.

III. Manila ropes of proper size shall be tied to the eyebolts provided for lifting on the
packing in such a way that the transport unit remains vertical . In the absence of
eyebolt ropes shall be tied in a such a way that the lifting off is vertical .
IV. Once the unit is cleared off the truck , the truck is moved away and the unit is slowly
brought down to the rolling pipes kept for movement of panels .
V. Then the unit shall be moved slowly to the storage area already identified .
VI. If the panels weight are less and shall be manually handled , then it shall be moved
to the storage area with proper manpower .
8.2 STORAGE OF PANELS
a) Make and provide tags on all components ( if it is unmarked ) , for easy identification
with record books.
b) Store in area protected from rain and sunlight .
c) Fire extinguishers shall be provided in storage area .
d) Open the wooden crates and inspect the panel for internal damages and tally the
equipment with the packing slip provided in each transport section .Damages if any
observed shall be brought to the notice of supplier / Transporter immediately .
e) After completion of inspection close all the panel doors , reclose the polythene
wrappers and ensure protection against ingress of moisture , dust , vermin etc into
the panels . Finally all panels shall be closed by their own wooden crates .
f) Panels has to be ensured for proper storage in indoor areas only .

Procedure for testing Secondary winding resistance on CT"S:-
i. Disconnect the external relay / meter connection at CT terminals
ii. With multimeter find out the winding resistance between secondary terminals. Allow
the reading to stabilize, before noting the value .
iii. For multitap CTs note the winding resistance between all terminals with
reference to S1 ( Secondary ) terminal .
Polarity tests on CTS mounted on the transformer:-
(For CTs separately shipped the procedure is similar)
i. The purpose of this test is to ascertain that S1&S2 ( Secondary ) terminals

bear correct phase relation with respect to the p1 & p2 terminals .
ii. A pulse of DC voltage is being applied at HV winding with +ve at 1U1 ( R
Phase ) & -ve at 1N. Due to this current flows in HV winding from 1U1 to 1N in that
direction. Due to mutual induction an emf is induced in the CT secondary across 1s1
& 1s2. For polarity to be correct 1s1 should be +ve with respect to 1s2. To ascertain
this a micro or milli ammeter is connected across CT secondary with positive lead of
meter at 1s1 & negative lead at 1s2.This procedure is same for CTS mounted in all
phases
ii. Upon application of pulse if the meter shows positive deflection then the polarity is
correct otherwise it is reversed.
iv. Test equipment required:
a) 1.5V battery
b) Push button switch
c) Motwane make multimeter
d d) OR polarity tester .

5. Ratio tests on CTs :
The tests are to be completed before installation using a primary injection kit to inject
rated currents through a temporary conductor passing through the center of CT core
i) Testing equipment required:
a) AC clamp meter (0-2500A)-1 No.

b) AC clamp meter (0-100A) - 1 No.
c) 1 ph supply through a temporary DB, shorting leads, connecting leads
ii) Purpose to conduct the ratio test is to confirm that the current transformation ratio as
given on the nameplate by the manufacturer is the same as actual .
6. Magnetization test for PS class CTs
i. The purpose of conducting this test is to ascertain that the knee point voltage
of the CT is greater than the minimum value specified by the manufacturer. Also that
the magnetizing current taken by the CT at 1/2 of the knee point voltage is less than
a specified minimum value. This is performed to ensure that the protection CT will
not saturate at current values much in excess of rated current.
ii. Test equipment required are:
a. Voltmeter AC (0-2000)
b. Clamp on ammeter AC (0-1A with a least count of 1 m A)
c. Step up transformer 240V/2000V, 1kva
d. Variac (0-240v) 1 kva
iii. 1 ph temporary power supply through through a DB
iv. Procedure for test
v. Put the MCB on after ensuring that the variac is in the minimum position
vi. Increase the output of variac in steps of 10V (being read at hv end of 2kv
transformer)
vii. Note the current passing through the CT secondary for each increase of 10V
a) Draw the graph with volts on x-axis and m A Current on the y-axis
b) When the increase in current is 50% for a corresponding 10% increase in the
voltage then the voltage applied is said to be knee point voltage.
c) Also note the current drawn at knee point voltage .

viii. Now compare the values of I knee and V knee with respect to the details available in
manufacturer test report and name plate details.
7. Insulation resistance test for CT secondary windings
a) This test is required to ascertain the insulation resistance of CT secondary with

respect to the earth.
a) Rotate the 1kv meggar at its rated speed for 60 seconds
Insulation resistance test on Fan Motor
i. The above test is done to ascertaining the insulation resistance value of the winding
to earth insulation of cooling fan motors .
ii. For carrying out the test, temporarily disconnect the external power wiring at
terminals. (Ensure the safety; the power wiring should be dead) .
ii. With line terminal of meggar connected to motor terminal & earth terminal of meggar
connected to earth, rotate speed (160 rpm) and note down the insulation resistance
as per deflection on meggar.

Recommended Meggar and Minimum IR values are as below:-
Voltage Meggar IR value (Min)
Upto 1000 V 1000 V 1 M. Ohm

1 KV to 33 KV 2.5 KV 100 M. Ohms
Above 33 KV 2.5/5 KV (Motorised) 1000 M. Ohms
If the test value is less than the above, arrange drying out for LT Switch Gear /
Panels.
Drying out:
Whatever method is employed for drying out, the general principle is to apply
heat continuously for a considerable time so as to drive out any mioisture which
may have become entrapped. During drying out period it is recommended to
take measurements of the insulation resistance periodically. It will generally be
found that at the beginning of the drying out, moisture is redistributed. After
sometime the insulation resistance value reaches a minimum value and then
stabilizes at this value for sometime, after which it begins to increase until it
reaches its maximum value. This maximum value is generally much greater than
minimum values given above. When the maximum value of the insulation
resistance has been reached, it is safe to put the LT Switch Gear / Panels into
service.

BUSDUCT ERECTION
a) Identify various sections and components of busducts as per drawing, while getting it
issued from stores
b) Install all the structural steel supports for busduct coming in indoor areas as per the
drawing
c) 10% DPT test shall be done for welds in erection of busduct supports
d) For outdoor portions of busduct, foundation shall be made for supporting structure as
per approved drawings & procedure. Support structures shall be erected as per
relevant drawings
e) Referring GA drawing of busduct, start erecting the busduct from SUT/UT, LV side
terminal enclosure
f) Use moving platform with ratchet arrangement for lifting busducts to position
g) Ensure correctness of orientation. Also ensure location dimension / clearances as

per GA drawing and part No. for each sub assembly being installed

h) Bellow joints of neoprene rubber bellow shall be installed at the termination of the
busducts at transformer LV enclosure box and LT Switch Gear / Panels cubicle
i) Flexible expansion joints shall be installed at locations as given in the GA drawing
j) Install seal off bushing in wall frame assembly as per the drawing
k) Bolt up the flanges of adjacent sections of busduct and also on to the terminal
equipments. Ensure proper alignment and air clearances as specified in the drawing.
Ensure gaskets are provided in between the flanges. Shellac shall be applied on
one face of gasket if new gasket is to be provided. Tighten the flanges to the torque
level as specified by the manufacturer. Size of the bolts, number of bolts and
accessories shall be as per drawing.
l) Various types of joints like welded rigid/expansion, bolted rigid/expansion /

flexible,shall be installed between adjacent sections of the busduct for linking up the
bus bars. The placement of joints shall be as per the drawing. Tighten them by
specified fasteners to the torque level as per manufacturers instructions. Ensure
bimetallic strips are provided at Cu. Joints as per the drawing.
m) Install the earthing strip along the busduct; clamp the strip on the busduct externally
on the clamps provided on the bus duct enclosure. Earthing of busduct to be
completed as per earthing drawings. Earth all the busduct supporting structures from
the earth strip running on the busduct.
n) Complete wiring / cabling for anti-condensation space heaters mounted in the

busduct as per the approved scheme
o) Check the continuity of busbars from terminal equipment on one side to that on the
other side.
p) Conduct contact resistance test at each bus bar joint using contact resistance test kit.
Connect the leads of the test kit across the joint, energize the kit and read the contact
resistance from the display. Refer annexure for format No.6.6KVSG/TCL/05
q) Provide insulating shrouds on the joint as per the drawing, also inspect for any
damages to the bus supporting insulators.
r) Close all the inspection covers ensuring that the rubber gasket is provided under all
the covers. Also, ensure proper cleaning and that no foreign material, dust etc. is left
inside the busduct.
s) Conduct IR test on the bus bars using 2.5 KV megger before and after the HV test.
Values of phase to earth and between phases are to be noted down in the format.
t) Conduct HV test at reduced voltage by applying 22.4 KV AC for one minute. First
apply between R phase to earth with Y & B connected to earth, then between Y
phase to earth with B phase connected to earth, and lastly B phase to earth. Note
down the readings as well as the leakage current at the start and the end of 60
seconds in each case. Final value of leakage current should not be more than initial
value. There shall be no cracks / porosity observed on the insulators. The insulators
should withstand the HV test. IR shall be taken before and after the HV test.

u) Install all filter type drain valves as per the GA drawing
v) Busduct can be linked onto its terminal equipments after the above is completed &
permission to that effect is taken from competent authority
w) Checklist for busducts and busbars is enclosed in Annexure No.6.6KVSG/CL/02
PROCEDURE FOR CHECKING OF BUSDUCTS
a) Check the name plate details as per the specifications

b) Check for any physical damage
c) Check for tightness of all bolts/clamps and connection terminals
d) Check for earthing of busducts as per drawing
e) Check for cleanliness of busduct
f) Check for insulation resistance of busduct
g) Check the contact resistance of busbars with micro ohm test kit
h) Perform HV test of busbar at reduced test voltage at 22.4 KV AC and also check the
IR value of the bus duct before and after the test. Check the bus insulators visually
i) Checklist for installation and testing of busducts is enclosed in annexure
6.6KVSG/CL/02
j) Check the busduct for water tightness checks. The enclosure of busduct shall
prevent the entrance of water when a stream from 25 mm diameter hose under a
head of 11 m andwith the nozzle 3 m from the busduct,is directed downwards on it
over a full length at an angle of 45 deg. from horizontal. The test is done for outdoor
portion of busduct. Checklist of busduct water tightness check is enclosed in
annexure 6.6KVSG/TCL/11
k) Check the busduct for air tightness. Close and seal drain holes and holes for
breather. When busduct is completely assembled in accordance with manufacturers
direction it is checked for air tightness by filling with air to a pressure of 150 mm of
water. After the air supply is shut off the pressure drop shall not be more than 75 mm
of water in 15 seconds. Check list for busduct air tightness check is enclosed in
Annexure 6.6KV SG/CL/12
15) Compare the nameplate details of the CB with specifications
16) Inspect the CB for any physical damage
17) Clean all the insulators & interruptor surface with dry cloth
18) Lubricate all the linkages, moving/sliding parts as per manufacturers
instructions
19) Use a torque gauge and check the tightness of all the bolts, clamps &
connecting terminals of VCB as per manufacturers recommendations
20) Conduct IR test at 2.5 KV & HV test at reduced test voltage of 22.4 KV AC on
CB in closed & racked out condition. For IR test refer annexure for format
No.6.6KV SG/CL/08. For HV test refer annexure for format No.415 V
SG/CL/06. Discharge the portion of CB on which HV test is completed by
using discharge rods connected to earth.
21) Perform manual & electrical closing , opening operation on CB. Check the
slow closing and opening operation of the CB. Confirm the operation of
mechanical operation indicators. Note down any deficiency observed.
22) Door interlocks, electrical and mechanical interlocks shall be checked
23) Insert the plug into the socket for control circuit connection between fixed
portion of cubicle and the CB truck, check that the plug can be inserted in
only one postion i.e correct position

24) Insert the CB and PT trucks inside their cubicles, check for their free
movement, check that the safety shutters over the cluster contacts in the
cubicle are operating satisfactorily.
25) Randomly interchange the CB trucks of same rating between different CB
cubicles. Ensure free movement of CB trucks in any of the CB cubicles.
Similarly check for PT trucks.
26) Use contact resistance test kit to measure the contact resistance across the
CB contacts for each phase. Also similarly take the contact resistance
measurement across the cluster contacts between the CB truck and the fixed
cubicle. Refer annexure
27) format No.6.6KV/SG/CL/05
28) Use 500V megger to measure the insulation resistance of the spring charge
motor, close & trip coils with respect to earth
29) Check for proper closing and opening operation manually and electrically.
Check the IR value with 5KV megger across the open CB contact. Also ensure the vacuum
healthiness of vacuum interrupter bottles of the CB as per the procedure given by
manufacturer .
Take the approved drawing and the specifications and compare the name plate details of the
equipments with it, also check the bill of materials in the drawing with equipment /
components provided in the panel. Use a green color pencil to mark on the schedule of bill
of material those materials, which are physically found on the panel & are inspected.
a) Take GA drawing of the respective LT Switch Gear / Panels and compare panel
number, NPC panel designation, feeder description and their sequence, VCB
numbers etc. encircle the ones found correct on the GA drawing by using a green
pencil.
b) Remove all gagging on the moving parts of the relays, inspect for any physical
damages.
8.8 CIRCUIT BREAKER TESTS AND CHECKS
30) Compare the nameplate details of the CB with specifications

31) Inspect the CB for any physical damage
32) Clean all the insulators & interruptor surface with dry cloth
33) Lubricate all the linkages, moving/sliding parts as per manufacturers
instructions
34) Use a torque gauge and check the tightness of all the bolts, clamps &
connecting terminals of VCB as per manufacturers recommendations
35) Conduct IR test at 2.5 KV & HV test at reduced test voltage of 22.4 KV AC on
CB in closed & racked out condition. For IR test refer annexure for format
No.6.6KV SG/CL/08. For HV test refer annexure for format No.415 V
SG/CL/06. Discharge the portion of CB on which HV test is completed by
using discharge rods connected to earth.
36) Perform manual & electrical closing , opening operation on CB. Check the
slow closing and opening operation of the CB. Confirm the operation of
mechanical operation indicators. Note down any deficiency observed.
37) Door interlocks, electrical and mechanical interlocks shall be checked
38) Insert the plug into the socket for control circuit connection between fixed
portion of cubicle and the CB truck, check that the plug can be inserted in
only one postion i.e correct position

39) Insert the CB and PT trucks inside their cubicles, check for their free
movement, check that the safety shutters over the cluster contacts in the
cubicle are operating satisfactorily.
40) Randomly interchange the CB trucks of same rating between different CB
cubicles. Ensure free movement of CB trucks in any of the CB cubicles.
Similarly check for PT trucks.
41) Use contact resistance test kit to measure the contact resistance across the
CB contacts for each phase. Also similarly take the contact resistance
measurement across the cluster contacts between the CB truck and the fixed
cubicle. Refer annexure
42) format No.6.6KV/SG/CL/05
43) Use 500V megger to measure the insulation resistance of the spring charge
motor, close & trip coils with respect to earth
44) Check for proper closing and opening operation manually and electrically.
45) Check the IR value with 5KV megger across the open CB contact. Also
ensure the vacuum healthiness of vacuum interrupter bottles of the CB as per
the procedure given by manufacturer .
9. ACCEPTANCE CRITERIA:
b) Conformity to schedule, drawings & specifications and manufacturers instructions.

c) Confirm the operation by keeping the breaker in test position.
10. CHECK LIST
a) The following checks has to be done as per this procedure
Sl.No. Procedure number Description

1. 415 VSG/CL/01 Installation of 6.6KV LT
Switch Gear / Panels
2. 415 VSG/CL/02 Installation & testing of
busducts
3. 415 VSG/CL/04 Testing of circuit breaker
4. 415 VSG/CL/05 Contact resistance test of
bus bar joints
5. 415 VSG/CL/06 High voltage test
6. 415 VSG/CL/07 Insulation resistance on
busbars
7. 415 VSG/CL/08 Insulation resistance test on
CB
8. 415 VSG/CL/09 Contact resistance test for
CB
9. 415 VSG/CL/03 Testing of LT Switch Gear /
Panels
10. 415 VSG/CL/10 Physical check for clearance
between bus bars
11. 415 VSG/CL/11 Checklist for busduct water
tightness test
12. 415 VSG/CL/12 Checklist for busduct air
tightness test

The following tests and checks will be done as per commissioning procedure No.
at the time of commissioning and therefore excluded in this procedure
Sr.No. Description
1 Testing of CT
2 Testing of PT
3 Precommissioning checks on LT Switch Gear
/ Panels
4 Name plate details of CB
5 CB operation time measurement test
6 Space heater checks
7 Illumination checks
8 Checklist for ammeter
9 Checklist for voltmeter
10 Checklist for transducer
11 Checklist for auxiliary DC relays
12 Checklist for under voltage relays
13 Checklist for trip circuit supervision relay
14 Checklist for time delay relay
15 Checklist for IR value & continuity of control
circuit
16 Checklist for IR value & continuity of power
circuit
11. PRECAUTION:
m) Check the physical conditions of 415 V LT Switch Gear / Panels board before shifting
from stores.
n) Qualified workmen shall be used for shifting and erection of 415 V LT Switch Gear /
Panels board
o) While transporting in the truck 415 V LT Switch Gear / Panels board shall be
tightened and wooden packings shall be provided
p) Safe PP ropes of size 1" shall be used for shifting the 415 V LT Switch Gear / Panels
board
q) Discharge the bus after conducting HV test and IR test with discharging rod
connected to the earth
r) Ensure safety of operating and testing personnel while conducting HV test. Rubber
hand gloves of suitable voltage grade have to be used while doing any online job.
Rubber mats of 415 V grade should be provided along the panel as per drawing
12. RECORDS
d) Manufacturers test reports for 415 V LT Switch Gear / Panels board shall be
available
e) Erection checklist No. for 6.6KV LT Switch Gear / Panels &
checklist No. for busduct installation.
f) Testing checklist and pre-commissioning checklist formats No.
g) Calibration certificate of testing instruments shall be available
13. DISTRIBUTION

Rolling pipes
b) Crow bars
c) Electrician tools
d) Spanner sets
e) Welding machine
C) Slings and ropes as per requirement
D) 2500, 1000, 500V meggers
E) Digital multimeter
F) Micro ohm meter
G) HV test kit 0-30KV with leakage current indicator
H) Torque wrench
I) Crane and truck for equipment shifting.
GENERAL
1.1 Introduction
The switchboards are designed to meet the requirements of modern industries and
power plants. The switchboards are offered either in single front or double front
design both in drawout/non drawout versions. These are of sheet steel construction
in modular design with standard dimensions. Both power and control contacts are of
fully drawout type for drawout panels. The switchboards are fully bolted design and
can be extended on both sides depending on the layout.
1.2 Busbar & cable chambers
The busbar are the main horizontal busbar run on the top of the panel and the feeder
vertical busbars run in liberally designed separate bus chambers supported on non-
hygroscopic insulators. In both single and double front design the control bus
chamber is provided at the front top of the panel. These control bus chambers are
used for running of control bus or serve as horizontal wire ways for control wires. A
spacious cable chamber is provided to facilitate easy layout and termination of
cables.
1.3 Drawout Modules
Each vertical panel accommodates standards modules of different sizes. The sizes
are in multiples of the smallest size to facilitate future alterations, with an increment
of 120 mm in case of 2450 mm height panel and 125 mm in case of 2250 mm heigh
panel.

Each module is provided with a single spindle cranking device for easy
insertion/withdrawal of the same. By cranking the spindle with the handle provided in
clockwise direction, the module moves in. By cranking the handle in the anti-
clockwise direction, the module moves out. For easy movement of drawout modules,
the modules run on rails. All control gear are mounted on the drawout modules.
Position indicators are provided for 'Service', 'Test' & 'Isolated' positions as per
requirement. The modules are provided with a first to make, last to break scrapping
earth contact to ensure safety of operation.
2. RECEIVING AT SITE
The switchboards are divided into convenient shipping section for ease of
transportation and handling. Before final packing in wooden case, these are
wrapped in polythene covers for waterproofing. Rubberised coir matting is provided
at various places between the panel and the wooden casing to protect the panel and
minimize shocks during transporting and handling. The following procedure should
be observed immediately on receipt of the panels.
2.1 Inspect the cases for any visible external damage
2.2 Report the transit damges, if any, to the goods carrier and immediately lodge the
claim with the underwriters
3. STORAGE
In case it is necessary to store the panels, the following care should be taken:
3.1 Open the wooden cases and inspect the panel for internal damages and tally the
equipment with the packing slip provided in each transport section. Damages, if any,
should be reported within two weeks of receipt of materials, to the underwriters.
3.2 After the inspection, close all the doors, re-close the polythene wrappers and ensure
protection against ingress of dust, moisture, vermin etc. into the panels
3.3 Where the prevailing weather conditions are humid, heat up the panels either by
energising the space heaters provided in the panel or by bulbs of suitable wattage.
3.4 Panels are to be stored indoor/or properly covered with water proof tarpaulin etc.
4. PREPARATION OF FOUNDATION
An uneven foundation will cause misalignment of horizontal busbars at transport

sections. Hence, ensure that foundation channels are properly levelled and
embedded in floor. Provision should be made for proper laying of cables in trenches

under the panels. Floor should be finished in all respects before taking up erection of
the panels.
5. INSTALLATION
5.1 Transport panels to the place of erection using cranes and lift the panels with the
help of eye bolts/lifting angles provided at the top of the panel using sufficiently long
slings. If crane facility is not available, transport, the panels with its wooden base on
suitable pipes without giving jolts.
5.2 Mounting each section of the foundation channels, align all sections and couple them
to form an integral assembly
5.3 Tighten all panel coupling bolts to ensure that no gap is left between the transport
section
5.4 Weld or bolt the foundation channel to base frame of panels. The bolt holes can be
accessed after removing the gland plate/bottom sheet in feeder chamber
5.5 Remove the top cover plates of the panels and clean contact surfaces of horizontal
busbar at transport sections to remove oxide film and apply a thin layer of
multipurpose grease. Note that, only a light application of grease is recommended
5.6 Couple the busbars at transport sections by links and bolts provided. Ensure that,
both flat and spring washers and bolts used are tightened properly such that proper
contact pressure is maintained at joints. Minimum overlap required for the purpose
shall be maintained by use of busbar links supplied by us along with each transport
section. Tightening of busbar joints at division of transport to be done as per
following bolting schedule.
A. M S Bolts 4.6 or 5.6 Grade:
Size Tightening (Kg f m) Torque values Nm

M5 2.5 0.25
M6 4 0.4
M8 10 1.0
M10 20 2.0
M12 35 3.5
B. H.T Bolts 8.8 Grade or higher:

M5 5 0.5
M6 8 0.8
M8 20 2.0
M10 35 3.5
M12 55 5.5

The grade of the bolts which are used in panel can be identified from the embossing
made on the bolts.
5.7 Couple earth bus in the same manner as above and connect control cables to
transport division terminals. Couple the control busbar at the transport sections.
5.8 Earth each cubicle at two points as per 'Indian Electricity' rules or in conformity with
the rules of local electrical inspectorate
5.9 Use the gland plates and cable glands for entry of power and control cables into the
MCC. Dress in the cable cores properly on the cable support provided in each cable
chamber
5.10 Terminate power and control cables to the respective terminals as per relevant
schematic drawings.
5.11 In case the incoming to the MCC is by busduct, couple the busbar of the busduct to
the main bus.
5.12 Ensure that the motor control center is installed in a well ventilated room
6. PRE-COMMISSIONING:
6.1 Inspect the main busbars, modules, compartments and cable chambers and remove
all foreign materials such as tools, wires etc. to avoid possible short circuits
6.2 Clean the inside surfaces, insulator surfaces, contacts, terminals etc. with a clean,
dry and soft cloth, as presence of harmful dusts will lead to tracking and flashover.
6.3 Check the tightness of bolts at each busbar joint. Power contacts on busbars are
accessible after removal of the barrier in front of vertical busbars. Check the
tightness of all power and control wiring.
6.4 Inspect all contactors, switches, relays and other components and make sure that
any blocking used for transportation purpose is removed to ensure free movement
6.5 Check all indicating meters and adjust pointer to zero position, if necessary, by zero
error adjusting screw on the meter
6.6 Check and test overload relays and other protection relays, if provided, for settings
and adjust them in accordance with the specified requirements using corresponding
schematic diagrams for guidance.
6.7 Check the fuse ratings as per relevant single line diagram / schematic drawings
6.8 Check alignment of drawout modules and circuit breakers and ensure proper
matching of power and controls contacts. Check door interlocking and defeat
mechanism for proper operation, if provided. Ensure that the doors do not open with
the switch/moulded case circuit breaker in 'ON' position.

6.9 After ensuring that no electrical power is connected to the Board, test insulation
values of the feeders, panels etc. using 500V megger as follows:
Drawout the feeder modules and check insulation value of each module once from
the incoming contact end and once from the outgoing contact end. Check the
insulation value of the panel including the incoming breaker / isolator.
In this context, it may be noted that if the storage period is long the insulation value
may be low. In such an event, the panels are to be heated with space heaters or with
lamps till insulation value is sufficient, i.e. more than 1 M ohms
6.10 The motor control centers are factory built assemblies and subjected to high voltages
test during inspection at our works. Hence, it is not recommended to conduct high
voltage test on MCC. However, if the HV test has to be repeated, then the same may
be conducted as per relevant IS/IEC specification (not more than 2 KV) by reducing
the test voltage as specified in IS / IEC specification. It is to be kept in mind that the
repeated HV test can cause deterioration of insulation and may contain components
not meant for repeated test, wire to be disconnected.
7. COMMISSIONING
7.1 Close suitably the unused cutouts for relays and meters not provide, and the opening
in the gland plates to prevent entry of dust and vermin. Keep all the doors and
covers tightly closed. The required protection class in possible only when all doors /
covers are closed.
7.2 Check all feeders and incoming feeders for proper functioning of various control and
power circuit components with their interlocks by applying control voltage.
7.3 Motor control center can now be energized
7.4 Check the actual current drawn by the motor at full load and adjust the bimetal to the
actual current value. Observe the modules for their performances and attend to the
discrepancy, if any. Check the module for any abnormalities immediately after
charging, like over heating, fuse blowing, arcing etc. and attend to it and recheck for
normal operation.
8. INSERTION/WITHDRAWAL OF DRAWOUT MODULES:
A portable tray carriage is supplied with the MCC to facilitate easy insertion /
withdrawal of modules. When the carriage is clamped, it provides an extension to
the base plate of the corresponding module chamber. The module placed on the
carriage gets automatically aligned even when it is outside the panel. Module can
now be gently moved in its chamber and racked in. This will avoid damage to the
control contacts. It will even be possible to do maintenance work on a module
keeping it on the tray carriage. Please adopt the following steps for
insertion/withdrawal of a module:
8.1 Switch 'OFF' the module

8.2 The relevant compartment door and the door of the cable chamber on the right side
of the module are to be opened (see drawing No.G1622-01). The left side bottom tip
of the carriage is then placed on the triangular space near the side guide of the base
plate of the compartment. The carriage is then swung-in on the right side to keep it
in level with the panel. Now this carriage clamps itself on the left. The clamp on the
right side is then pressed down so that the carriage is clamped firmly to the panel.
8.3 The module can now be cranked out and withdrawn to slide over the carriage
8.4 For inserting a module into a panel, it has to be placed in two rails, pushed-in to
isolated position and then cranked in
8.5 Blanking plates
When the modules are taken out of the compartment, the blanking plates provided
are to be used to cover up the cutout on the door only in case of MCC panels with
height 2450 mm
9. MAINTENANCE
Proper maintenance of MCCs ensures longer life and proper operation. It is

therefore imperative that the equipment is regularly maintained as per the following
recommended schedule:
9.1 Re-tighten all busbar joints and cable connection within a week after commissioning
and reaching the Max. load. Repeat the same after another week of loading the
panel with rated current. Check tightness of all joints and connections during
maintenance shut downs
9.2 Do not allow water, cement mortar etc. to fall on the panels during erection. Keep
drawn out trays covered to avoid accumulation of dust if they are kept outside the
panels for any reason. Drawout modules and circuit breakers/relays are to be
handled carefully only by authorised and competent personnel to avoid damage.
9.3 For any kind of working on feeder tray, including replacement of fuses, draw out the
modules in the panel compartment. Before inserting a module into the panel where a
vertical bus is energized, check the IR values of the modules using 500V megger as
described under 6.9 of chapter "Pre-commissioning". Check the IR values of the
outgoing cable connections. Ensure that no foreign material is present in the
compartment. The switch is in OFF position.
9.4 All compartments including control contacts should be cleaned at definite intervals.
The frequency of cleaning entirely depends on environmental conditions of the place.
Any accumulation of dust, dirt or foreign material should be removed only with the
panels/modules in de-energized condition.
9.5 Keep all doors and covers closed. The required ingress protection will be lost if all
the covers and openings in gland plates are not closed.
9.6 Inspect all components from time to time ensuring their proper functioning.

9.7 Replace badly worn out contacts immediately. Blackening of silver coated contacts
does not affect performance. To clean the contacts, carbon tetrachloride or suitable
cleaning solution has to be used. Do not use emery paper or metal files, which will
damage the plated parts.
9.8 For inspection and maintenance of circuit breakers, draw out the breaker fully. With
this free access is available to all parts of the breakers. Further details regarding
breaker maintenance can be obtained from the relevant manufacturers manual.
9.9 For general inspection and maintenance of relays, following points are to be
observed.
Check that the movements are free and the contacts close and open by hand
operation. Ensure operation of flag indicators, if provided.
9.10 Lubricate the spindle and other sliding parts of the module periodically with general
purpose lubricant to ensure free movement
9.11 Apply grease on the guide rails and guide with a general purpose grease for smooth
movement of the modules
9.12 The MCC is supplied with a protection class as per the requirement. To ensure that
the protection class is maintained, keep the panel doors, covers and other
compartments properly closed at all times during operation.
9.13 Use only panel key supplied along with equipment, for opening/closing of the module
doors & cable chamber doors. Other tools like screwdrivers etc. should not be used
for this purpose, as it will damage the recess.
9.14 Only genuine spares should be used for replacement
Circuit diagrams furnished also include "component details sheet" which indicates
specification, type and make of componenets, based on which spares can be
ordered.
9.15 For any extension / modification of modules, standard parts are available which can
be had on furnishing the details
GENERAL
1.2 Introduction
The switchboards are designed to meet the requirements of modern industries and
power plants. The switchboards are offered either in single front or double front
design both in drawout/non drawout versions. These are of sheet steel construction
in modular design with standard dimensions. Both power and control contacts are of
fully drawout type for drawout panels. The switchboards are fully bolted design and
can be extended on both sides depending on the layout.
1.2 Busbar & cable chambers
The busbar are the main horizontal busbar run on the top of the panel and the feeder
vertical busbars run in liberally designed separate bus chambers supported on non-

hygroscopic insulators. In both single and double front design the control bus
chamber is provided at the front top of the panel. These control bus chambers are
used for running of control bus or serve as horizontal wire ways for control wires. A
spacious cable chamber is provided to facilitate easy layout and termination of
cables.
1.3 Drawout Modules
Each vertical panel accommodates standards modules of different sizes. The sizes
are in multiples of the smallest size to facilitate future alterations, with an increment
of 120 mm in case of 2450 mm height panel and 125 mm in case of 2250 mm heigh
panel.
Each module is provided with a single spindle cranking device for easy
insertion/withdrawal of the same. By cranking the spindle with the handle provided in
clockwise direction, the module moves in. By cranking the handle in the anti-
clockwise direction, the module moves out. For easy movement of drawout modules,
the modules run on rails. All control gear are mounted on the drawout modules.
Position indicators are provided for 'Service', 'Test' & 'Isolated' positions as per
requirement. The modules are provided with a first to make, last to break scrapping
earth contact to ensure safety of operation.
2. RECEIVING AT SITE
The switchboards are divided into convenient shipping section for ease of
transportation and handling. Before final packing in wooden case, these are
wrapped in polythene covers for waterproofing. Rubberised coir matting is provided
at various places between the panel and the wooden casing to protect the panel and
minimize shocks during transporting and handling. The following procedure should
be observed immediately on receipt of the panels.
2.1 Inspect the cases for any visible external damage
2.2 Report the transit damges, if any, to the goods carrier and immediately lodge the
claim with the underwriters
3. STORAGE
In case it is necessary to store the panels, the following care should be taken:
3.1 Open the wooden cases and inspect the panel for internal damages and tally the
equipment with the packing slip provided in each transport section. Damages, if any,
should be reported within two weeks of receipt of materials, to the underwriters.

3.2 After the inspection, close all the doors, re-close the polythene wrappers and ensure
protection against ingress of dust, moisture, vermin etc. into the panels
3.3 Where the prevailing weather conditions are humid, heat up the panels either by
energising the space heaters provided in the panel or by bulbs of suitable wattage.
3.4 Panels are to be stored indoor/or properly covered with water proof tarpaulin etc.
5. PREPARATION OF FOUNDATION
An uneven foundation will cause misalignment of horizontal busbars at transport

sections. Hence, ensure that foundation channels are properly levelled and
embedded in floor. Provision should be made for proper laying of cables in trenches
under the panels. Floor should be finished in all respects before taking up erection of
the panels.
5. INSTALLATION
5.1 Transport panels to the place of erection using cranes and lift the panels with the
help of eye bolts/lifting angles provided at the top of the panel using sufficiently long
slings. If crane facility is not available, transport, the panels with its wooden base on
suitable pipes without giving jolts.
5.2 Mounting each section of the foundation channels, align all sections and couple them
to form an integral assembly
5.3 Tighten all panel coupling bolts to ensure that no gap is left between the transport
section
5.4 Weld or bolt the foundation channel to base frame of panels. The bolt holes can be
accessed after removing the gland plate/bottom sheet in feeder chamber
5.5 Remove the top cover plates of the panels and clean contact surfaces of horizontal
busbar at transport sections to remove oxide film and apply a thin layer of
multipurpose grease. Note that, only a light application of grease is recommended
5.6 Couple the busbars at transport sections by links and bolts provided. Ensure that,
both flat and spring washers and bolts used are tightened properly such that proper
contact pressure is maintained at joints. Minimum overlap required for the purpose
shall be maintained by use of busbar links supplied by us along with each transport
section. Tightening of busbar joints at division of transport to be done as per
following bolting schedule.
A. M S Bolts 4.6 or 5.6 Grade:

M5 2.5 0.25
M6 4 0.4
M8 10 1.0

M10 20 2.0
M12 35 3.5
B. H.T Bolts 8.8 Grade or higher:

M5 5 0.5
M6 8 0.8
M8 20 2.0
M10 35 3.5
M12 55 5.5
The grade of the bolts which are used in panel can be identified from the embossing
made on the bolts.
5.7 Couple earth bus in the same manner as above and connect control cables to
transport division terminals. Couple the control busbar at the transport sections.
5.8 Earth each cubicle at two points as per 'Indian Electricity' rules or in conformity with
the rules of local electrical inspectorate
5.9 Use the gland plates and cable glands for entry of power and control cables into the
MCC. Dress in the cable cores properly on the cable support provided in each cable
chamber
5.10 Terminate power and control cables to the respective terminals as per relevant
schematic drawings.
5.11 In case the incoming to the MCC is by busduct, couple the busbar of the busduct to
the main bus.
5.12 Ensure that the motor control center is installed in a well ventilated room
6. PRE-COMMISSIONING:
6.1 Inspect the main busbars, modules, compartments and cable chambers and remove
all foreign materials such as tools, wires etc. to avoid possible short circuits
6.2 Clean the inside surfaces, insulator surfaces, contacts, terminals etc. with a clean,
dry and soft cloth, as presence of harmful dusts will lead to tracking and flashover.
6.3 Check the tightness of bolts at each busbar joint. Power contacts on busbars are
accessible after removal of the barrier in front of vertical busbars. Check the
tightness of all power and control wiring.
6.4 Inspect all contactors, switches, relays and other components and make sure that
any blocking used for transportation purpose is removed to ensure free movement

6.5 Check all indicating meters and adjust pointer to zero position, if necessary, by zero
error adjusting screw on the meter
6.6 Check and test overload relays and other protection relays, if provided, for settings
and adjust them in accordance with the specified requirements using corresponding
schematic diagrams for guidance.
6.7 Check the fuse ratings as per relevant single line diagram / schematic drawings
6.8 Check alignment of drawout modules and circuit breakers and ensure proper
matching of power and controls contacts. Check door interlocking and defeat
mechanism for proper operation, if provided. Ensure that the doors do not open with
the switch/moulded case circuit breaker in 'ON' position.
6.9 After ensuring that no electrical power is connected to the Board, test insulation
values of the feeders, panels etc. using 500V megger as follows:
Drawout the feeder modules and check insulation value of each module once from
the incoming contact end and once from the outgoing contact end. Check the
insulation value of the panel including the incoming breaker / isolator.
In this context, it may be noted that if the storage period is long the insulation value
may be low. In such an event, the panels are to be heated with space heaters or with
lamps till insulation value is sufficient, i.e. more than 1 M ohms
6.10 The motor control centers are factory built assemblies and subjected to high voltages
test during inspection at our works. Hence, it is not recommended to conduct high
voltage test on MCC. However, if the HV test has to be repeated, then the same may
be conducted as per relevant IS/IEC specification (not more than 2 KV) by reducing
the test voltage as specified in IS / IEC specification. It is to be kept in mind that the
repeated HV test can cause deterioration of insulation and may contain components
not meant for repeated test, wire to be disconnected.
7. COMMISSIONING
7.3 Close suitably the unused cutouts for relays and meters not provide, and the opening
in the gland plates to prevent entry of dust and vermin. Keep all the doors and
covers tightly closed. The required protection class in possible only when all doors /
covers are closed.
7.4 Check all feeders and incoming feeders for proper functioning of various control and
power circuit components with their interlocks by applying control voltage.
7.3 Motor control center can now be energized
7.4 Check the actual current drawn by the motor at full load and adjust the bimetal to the
actual current value. Observe the modules for their performances and attend to the
discrepancy, if any. Check the module for any abnormalities immediately after
charging, like over heating, fuse blowing, arcing etc. and attend to it and recheck for
normal operation.

8. INSERTION/WITHDRAWAL OF DRAWOUT MODULES:
A portable tray carriage is supplied with the MCC to facilitate easy insertion /
withdrawal of modules. When the carriage is clamped, it provides an extension to
the base plate of the corresponding module chamber. The module placed on the
carriage gets automatically aligned even when it is outside the panel. Module can
now be gently moved in its chamber and racked in. This will avoid damage to the
control contacts. It will even be possible to do maintenance work on a module
keeping it on the tray carriage. Please adopt the following steps for
insertion/withdrawal of a module:
8.1 Switch 'OFF' the module
8.2 The relevant compartment door and the door of the cable chamber on the right side
of the module are to be opened (see drawing No.G1622-01). The left side bottom tip
of the carriage is then placed on the triangular space near the side guide of the base
plate of the compartment. The carriage is then swung-in on the right side to keep it
in level with the panel. Now this carriage clamps itself on the left. The clamp on the
right side is then pressed down so that the carriage is clamped firmly to the panel.
8.3 The module can now be cranked out and withdrawn to slide over the carriage
8.4 For inserting a module into a panel, it has to be placed in two rails, pushed-in to
isolated position and then cranked in
8.5 Blanking plates
When the modules are taken out of the compartment, the blanking plates provided
are to be used to cover up the cutout on the door only in case of MCC panels with
height 2450 mm
9. MAINTENANCE
Proper maintenance of MCCs ensures longer life and proper operation. It is

therefore imperative that the equipment is regularly maintained as per the following
recommended schedule:
9.1 Re-tighten all busbar joints and cable connection within a week after commissioning
and reaching the Max. load. Repeat the same after another week of loading the
panel with rated current. Check tightness of all joints and connections during
maintenance shut downs
9.2 Do not allow water, cement mortar etc. to fall on the panels during erection. Keep
drawn out trays covered to avoid accumulation of dust if they are kept outside the
panels for any reason. Drawout modules and circuit breakers/relays are to be
handled carefully only by authorised and competent personnel to avoid damage.
9.3 For any kind of working on feeder tray, including replacement of fuses, draw out the
modules in the panel compartment. Before inserting a module into the panel where a
vertical bus is energized, check the IR values of the modules using 500V megger as
described under 6.9 of chapter "Pre-commissioning". Check the IR values of the

outgoing cable connections. Ensure that no foreign material is present in the

compartment. The switch is in OFF position.
9.4 All compartments including control contacts should be cleaned at definite intervals.
The frequency of cleaning entirely depends on environmental conditions of the place.
Any accumulation of dust, dirt or foreign material should be removed only with the
panels/modules in de-energized condition.
9.5 Keep all doors and covers closed. The required ingress protection will be lost if all
the covers and openings in gland plates are not closed.
9.6 Inspect all components from time to time ensuring their proper functioning.
9.7 Replace badly worn out contacts immediately. Blackening of silver coated contacts
does not affect performance. To clean the contacts, carbon tetrachloride or suitable
cleaning solution has to be used. Do not use emery paper or metal files, which will
damage the plated parts.
9.8 For inspection and maintenance of circuit breakers, draw out the breaker fully. With
this free access is available to all parts of the breakers. Further details regarding
breaker maintenance can be obtained from the relevant manufacturers manual.
9.9 For general inspection and maintenance of relays, following points are to be
observed.
Check that the movements are free and the contacts close and open by hand
operation. Ensure operation of flag indicators, if provided.
9.10 Lubricate the spindle and other sliding parts of the module periodically with general
purpose lubricant to ensure free movement
9.11 Apply grease on the guide rails and guide with a general purpose grease for smooth
movement of the modules
9.12 The MCC is supplied with a protection class as per the requirement. To ensure that
the protection class is maintained, keep the panel doors, covers and other
compartments properly closed at all times during operation.
9.13 Use only panel key supplied along with equipment, for opening/closing of the module
doors & cable chamber doors. Other tools like screwdrivers etc. should not be used
for this purpose, as it will damage the recess.
9.14 Only genuine spares should be used for replacement
Circuit diagrams furnished also include "component details sheet" which indicates
specification, type and make of componenets, based on which spares can be
ordered.
9.15 For any extension / modification of modules, standard parts are available which can
be had on furnishing the details

BASEFRAME ERECTION ON EP"S GROUTED IN THE SIDE WALLS / COLOUMNS

v) Check the location, dimension as per the GA drawing .
w) Base channels shall be properly identified with respect to their particular panels
before installing in to their respective position . If base frames are not available it
shall be fabricated at site to suit for erection of panels .Painting applied shall be as
per approved Painting Procedure and final finish paint shall be of black colour .
x) The position of the base channel with respect to grid reference or wall shall be
checked .
y) Check the embedded plate (EP) for levelling with water level. Remove the paint from
base frame surface wherever it is to be welded to EP. Also clean the EP. The base
frames shall be placed over EP"S as per GA drawings .
z) The base frame shall be checked for levelling and alignment. If deviations are
observed it can be corrected with shims . Level difference of more than 2 mm is not
allowed .
aa) After ensuring of alignment , tack welding shall be carried out between EP"s and
Base frames .
bb) After ensuring of alignment welding shall be carried out between base frame and
EP"S . Size of the fillet weld shall be 6 mm. Welding shall be carried out as per
approved welding procedure .
cc) The length of welding and gaps between welding shall be decided on case to case
basis .
dd) 10% of total weld length shall be subject to dye penetration testing .
ee) After completion of welding , damage areas of painting in Base channel shall be
touched with primer and Enamel paint . Finish coat shall be black enamel paint .
ff) If EP"S are not available at the proper location , base frames shall be embedded to
the walls / Columns by means of Anchor Fasteners . Anchor fastener shall be of M12
/ 16 . Total numbers to be Anchor fastener to be installed shall be as per the
recommendation of Engineer – In Charge .
8.9 PRE- COMMISSIONING CHECKS

The following tests are to be done before commissioning the switch gear .Detailed
testing procedure and its check list shall be covered in Commissioning Procedure.
A. Testing of Breaker
1. Check control wiring for correctness of connections , Continuity and IR Values
2. Check for Proper closing & Opening of Breakers electrically

3. Check for Breaker closing and tripping time measurement .

4. Check for Trip free and anti pumping operation
5. Measurement of Contact Resistance between Moving and closing contacts of
each pole of individual circuit Breaker.
6. IR Value between all poles and poles to earth of Individual circuit Breaker .
7. Check for spring charging correct operation of limit switches and time of
charging and also check for simultaneous closing of 3 poles .
B. Testing of Current Transformer
1. IR values between windings and winding terminals to body .- 1 K.V Meggar
2. Polarity check .- D.C Check
3. Ratio test – Primary Injection
4. Magnetisation Characteristics for PS Class CT"S – Secondary Injection
5. Secondary Winding Resistance – Ohm meter
C. Testing of Voltage Transformer
1. IR Values between windings and winding terminals to body -1 K.V Meggar
2. Polarity test – Primary Injection
3. Ratio test - Secondary Injection
D. Testing of Meters.
1. Calibration of Meters
2. Check CT & VT connections with reference to their polarities for power type
meters .
E. Testing of Relays
1. Check operating characteristic by secondary injection
2. Check minimum pick up voltage on DC Coils
3. Check for relay settings
4. Check CT & VT connection with particular reference to their polarities for
directional relays .
F. Switch Fuse Feeder Units :-
1. Check operation of indicating lamps
2. Check operation of micro switch
G. Over Load Relays :-
1. Check continuity of NC Contact and Open circuit for NO Contact .Check
operation of Relay for Test / Reset PB.
2. Check for Forward – Reverse interlock if any .
H. Space Heaters & Illumination Circuits :-

1. Wiring Continuity.
2. Space Heater Resistance
3. IR Value of Space Heater
4. IR Value of Illumination Circuit
5. ThermoCouple Seting
I. Cabling & Termination :-
1. Size of Power Cable and its size of lugs .
2. Check for proper crimping of Power & Control Cable by use of Crimping paste
and correct crimping tool
3. Check for connection tightness and its dressing
4. Check for sealing of extra holes at gland plates by approved sealing
compounds .
J. Control Transformer :-
1. Check for Turns ratio
2. Check for proper earthing
Check for IR Value
8.5 BUS DUCT ERECTION

Prelayout survey
Before starting the erection work, check that the center line of the complete bus duct shall be
inline with the center line of the Auxiliary Transformer . In case of any substantial deviation
which may effect the erection of bus duct installation the same should be referred to
Purchaser engineers. The remedial measures should be planned in advance which may
consist of leveling by suitable packings, chipping of the concrete floor or wall etc. or
rectification of the components with the concurrence of Engineer –In – Charge .
8.5.1 Sequence of erection

The following Sequence will be followed.
Erection of steel work.
Initially Temporary supports like "H " Frame or temporary steel supports hanged from top will
be provided for lifting of enclosures with Busbars . Permanent supports will be made ( Welded
with the EP"S ) only when rough alignment of Bus Duct is completed and before joining of
enclosures / Bus bars .
Since all permanent supports are Hot Galvanized , the area of structure to be welded with
EP"S shall be degalvanized by Pickling process or by Oxy – Acyletene torch .Then all the
supporting structures will be installed and welded to the EP’s or fixed to the embedded bolts
as per approved drawings. Welding will be done by Qualified welders and as per approved

procedures . 10% DPT will be done for the welding of Structural steel supports as per
approved DPT procedure .
Next place all longitudinal cross channels in positions. Adjust all levels & bolt/weld them.
Check up the correctness of the levels & positions of various installed structures .
Indoor portion of the bus duct shall be supported from the ceiling beams or side walls as per
approved drawings . For outdoor portions of bus duct, foundation shall be made for
supporting structure as per approved drawings & procedure. Support structures shall
be erected as per relevant approved drawings .
8.5.2 Erection of enclosure along with its bus bars
Before the installation of enclosures in position, each assembly of enclosure and conductors
complete with insulation support will be checked for correctness and cleanliness. The various
enclosure assemblies will be erected as per layout drawing.
Bolt up the flanges of adjacent sections of busduct . Ensure proper alignment and air
clearances as specified in the drawing. Ensure gaskets are provided in between the
flanges. Shellac shall be applied on one face of gasket if new gasket is to be
provided. Tighten the flanges to the torque level as specified by the manufacturer.
Size of the bolts, number of bolts and accessories shall be as per drawing.
For outdoor portions of bus duct, foundation shall be made for supporting structure
as per approved drawings & procedure. Support structures shall be erected as per
relevant approved drawings .
8.5.3 Erection of Bus bar joints .
Bus bar joints will be bolted as specified for the installation as follows .
a. Check the contact surface
- Surface will be flat and even.
- Remove any irregularities if any (Slight hammering using wood )
b. Preparation of Contact
- Never use abrasives for cleaning.
- Clean the surface with Acetone / CTC
- Apply a thin and even coating of Neutral grease.
c. Mounting instructions
- Bring the pieces to be assembled to contact ,then place bolts, flats washers.
- Gradually tighten the bolts screws or nuts and finally apply tightening torque using torque
spanner .
- Torque values shall be as per Manufacturers recommendation .
- If mounting is incorrect, dismantle while connection and remount.
8.5.4 Erection of Flexible Connections
Only tinned copper flexible are envisaged in this Job and this are provided between the bus
duct and the equipment .The surfaces are silver plated and protected. Bimetallic washers

shall be used at locations between dissimilar metals and tightness of bolt shall be as per
Manufacturers recommendation .
8.5.5 Erection of Flexible Expansion Joints and Wall frame assembly
Flexible expansion joints shall be installed at locations as given in the GA drawing .
Tightening of Bolts shall be as per Manufacturers recommendation .
Install seal off bushing in wall frame assembly as per the drawing .
8.5.6 Erection of Rubber Bellows Assembly
Bellows are made of neoprene rubber and the purpose is to achieve a flexible airtight
and insulating junction . The bellow is designed for flanged connections , shall be
installed at the termination of the busducts at transformer LV enclosure box and
switchgear cubicle .
Mounting procedure will be as given below:
1.Preliminary check: - Check main dimension.

1
- Confirm no damage (Cracks, tears etc)
2. Preparation - Carefully clean the resting surface.

- Remove all the traces of grease, dust etc.
- Removal all the irregularities if any by grinding.
- Fit the bellows on one of its supports, taking care

not to scratch .
3. Final fitting - To be done only after bolted connections are done

after checking and confirming nothing is kept inside.
- Fit the bellows on its 2nd support.
- Tighten all bolts as per Manufacturers Recommendation .
8.5.7 Space Heater Wiring :

Complete wiring / cabling for anti-condensation space heaters mounted in the
busduct as per the approved scheme . Before closing of split covers ensure that
space heaters are temporarily checked for its operation .
8.5.8 Erection of Silica Gel Breather and Drain valves :
Fixing of Silica Gel Breather and Filter type drain valves shall be erected as per
Drawing . Before lifting for erection , check for physical condition of silica gel .

8.5.9 Cleaning of Bus Duct and closing of Covers
Before putting the split covers all the insulator will be cleaned again and will be checked for
any damage . The Bus Duct will also be cleaned and dried up for any moisture / condensate.
Thoroughly check the interior of every enclosure and ensure that these are free from any
foreign Matter. Provide insulating shrouds on the joint as per the drawing .
8.5.10 Earthing of Bus Duct
Install the earthing strip along the busduct; clamp the strip on the busduct externally on the clamps provided on
the bus duct enclosure. Earthing of busduct to be completed as per earthing drawings. Earth all the busduct
supporting structures from the earth strip running on the busduct as per the relevant approved drawing .

Erection Procedure For 415 V LCC, LDBS, LPS, SP

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Erection Procedure For 415 V LCC, LDBS, LPS, SP

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EP/LT PANEL/REL/KAIGA 3&4 / 014 PAGE

ERECTION PROCEDURE FOR 415 V SWITCH GEAR .

1) Module specifications PP-E-1754 ( E-6 )

Responsibility of implementation of this procedure lies with the Site In Charge.

a) Approved drawings shall be available for erection of 415 V Switch Gear .

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

g) Ensure that proper security arrangement / lockable door is provided before

a) Rolling pipes / Rollers

8.1 SHIFTING OF MATERIALS FROM STORAGE YARD TO ERECTION SPOT

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

8.3 PANEL ERECTION

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Voltage Meggar IR value (Min)

Upto 1000 V 1000 V 1 M. Ohm ( Schneider to comment )

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

8.5 PROCEDURE FOR CONDUCTING VARIOUS PRELIMINARY CHECKS ON

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

5) Check for cleanliness of busduct .

a) Conformity to schedule, drawings & specifications and manufacturers instructions.

10. CHECK LIST

a) The following checks has to be done as per the Erection procedure. .

Sl.No. Procedure number Description

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

j) Do not store panel in open and humid areas.

a) Manufacturers test reports for LT Switch Gear shall be available

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

8.1 RECEIPT OF PANELS & ACCESSORIES :

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Procedure for testing Secondary winding resistance on CT"S:-

i. Disconnect the external relay / meter connection at CT terminals

(For CTs separately shipped the procedure is similar)

i. The purpose of this test is to ascertain that S1&S2 ( Secondary ) terminals

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

5. Ratio tests on CTs :

a) AC clamp meter (0-2500A)-1 No.

iv. Procedure for test

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

7. Insulation resistance test for CT secondary windings

a) This test is required to ascertain the insulation resistance of CT secondary with

Insulation resistance test on Fan Motor

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

Recommended Meggar and Minimum IR values are as below:-

Voltage Meggar IR value (Min)

Upto 1000 V 1000 V 1 M. Ohm

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

g) Ensure correctness of orientation. Also ensure location dimension / clearances as

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

i) Flexible expansion joints shall be installed at locations as given in the GA drawing

l) Various types of joints like welded rigid/expansion, bolted rigid/expansion /

n) Complete wiring / cabling for anti-condensation space heaters mounted in the

Prepared By : S.M.Patil Concurred By : V.Chandra SekarApproved By : J.P.Athalye

u) Install all filter type drain valves as per the GA drawing

w) Checklist for busducts and busbars is enclosed in Annexure No.6.6KVSG/CL/02

PROCEDURE FOR CHECKING OF BUSDUCTS

a) Check the name plate details as per the specifications