Commissioning Lecture
Commissioning Lecture
Commissioning Lecture
b.
Directional properties
c.
4. On load tests
Summary
1.
2.
Primary injection
(incl. C.T. ratio, phasing and mag. curve)
3.
On load tests
Key diagram
Delegate responsibilities
Insulation Tests
Mechanical inspection
Out-going contact wiring
External resistors
C.T. shorting and isolating switches
Contact follow-through and pressures
Electrical checks on each basic electrical function
to prove satisfactory operation
Test results (record and maintenance purposes)
Stability tests
Test results
On load tests
Stability tests
Directional properties
At the end of each stage ask yourself :Is there anything wrong, wiring or otherwise,
that I
have not checked that may prevent correct
operation
If so, CHECK IT OUT !
10
Maintenance of
Protective Relays (1)
Frequency of Maintenance
Dictated by :a) The site condition
b) The availability of maintenance staff and
resources
c) The availability of plant outage times
d) The risks involved if the protection
should fail
e) The type of relay construction
11
Maintenance of
Protective Relays (2)
Maintenance of
Protective Relays (3)
Onerous site conditions :1. Dusty or dirty environments
2. Corrosive chemical atmospheres
3. Frequent or continuous vibration
4. High humidity
5. High or cycling temperatures
6. Consistently high levels of energising or auxiliary
quantities
Typically maintain every 12-18 months under ideal
conditions and decrease frequency
13
Maintenance of
Protective Relays (4)
Visual inspections
Calibration tests
Trip testing
14
Maintenance of
Protective Relays (5)
15
Maintenance of
Protective Relays (6)
Wrist straps
16
Protect boards
Corrective Maintenance of
Protective Relays (1)
Cleaning solvents
Trichlortrifluorethane (Ozone damaging)
(Arklone, Freon, Flourisol and Supersolve)
PROZONE
Contact lubricants and other lubricants
Contact cleaning burnishers
Contact pressures and settings
Dust removal
Relay recalibration (Why?)
17
18
19
20
To CT
CT test
To
test
windings
windings
(if any)
(if any)
21
B
To main
main
To
current
current
transformers
transformers
C N
A
To
To main
mainVTVT
A
CurrentB
test
socketsC
B Voltage
test
C sockets
N
To main current
transformers
22
To main VT
Current Transformer
Polarity Check
P2
P1
S2
S1
Battery
23
Push
button
switch
Current Transformer
Ratio Check
A
C
A2
Temporary
short
circuit
51
P1
51
S1
P2 S 2
51
64
A1
Primary injection
test set
250V AC supply
24
Test plug
insulation
A
P1
To relay
coils
V
S1
Variable
transformer
250V 8A
250V
AC
supply
S2
P2
Main circuit
breaker open
25
Step-up transform
if required
Voltage Transformer
Phasing Check
A
B
C
A
V1
V2
C
VN
VL
V1
V2
A
26
Phase rotation
meter
Coarse
control
reactor
Range
adjusting CT
K1
K2
250V
AC
supply
51 Relay
coil
Start
timer
Supply
switch
Backing
transformer
10% control
Stop
timer
Injection
Medium transformer Relay shortcircuiting switch
control
reactor
L2
50Hz
0.1A
10X5X2X1X
0.2A
220/250V
AC
Supply
50/60Hz
Variac V1
60Hz
0.5A
50Hz
1A
2A
O/V Detector
Circuit
L1
5A
Supply
Contractor
Supply Shorting
Switch
28
10A
Timer
T1 Injection
Start
Matching
(Break to Start)
C.T.
Output
to
Relay
Sensitivity Check on
Biased Differential Relay
B
B
OP
Test plug
fingers
Over current
test set
To main current
transformers
250V
A.C. supply
29
B
OP
I1+I2
A1
Overcurrent
test set
To main current
transformers
250V A.C.
supply
30
I2
I1
A2
R
Test plug
fingers
B
OP
I1+I2
R1
Test plug
fingers
A2
A1
To main current
transformers
250V A.C.
supply
31
I2
I1
R2
A1 and A2 Ammeters
OP Relay operating coil
B Relay bias coil
Sensitivity Test
Feeder isolated
A
B
C
Test
plug
Relay
contact
fingers
Overcurrent 250V
test set A.C. supply
B
OP
OP
Pilots
32
250V
A.C.
supply
To main
current
transformers
C
N
Overcurrent
test set
Test plug
in test block
33
Filter
network
46
Relay
coil
A
B
C
N
Choke
Variable
transformer
for current
control
67
Relay
current coil
Range adjusting CT
440/110V
phase shifting
transformer
PA
PA
67
Relay
voltage coil
Variable transformer
for voltage control
250V A.C.
supply
35
Primary Check on
Main Current Transformers
Temporary three
phase short circu
Primary
injection
test set
250V
A.C. supply
51 Overcurrent relay
64 Earth fault relay
A
Ammeter
36
5
1
5
1
5
1
6
4
Primary
injection
test set
5
1
B
51
C
51
64
37
Direction of power
flow
Load
for relay operationcurrent
A
V
PA
38
Ammeter
Voltmeter
Phase angle
meter
>
PA
PA
B
C
Directional overcurrent
relays
Commissioning & Maintenance of Protective Relays
20 19 18
17 16 15
14 13 12 11
Test plug
To main VT and CT
39
10
1S
2
S
2
IA
A
51
51
A
V
PA
40
51
Ammeter
Voltmeter
Phase angle meter
Load
Load
current
current
PA
P
A
Temporar
y
short
circuit
connectio
Insulating
ns
strips
in
relay or test
block
contact fingers
Directional
earth
fault relay
V
1V
2
V
L
V
V
P
PA
A
87 Generator differential re
V
Voltmeter
A Ammeter
250V A.C.
supply
Generato
r
Isolating
links
A
B
C
41
87
87
87
A
B
C
87
87
87
87 Generator differential r
V
Voltmeter
42
Generato
r
Temporary
short
circuit
A
B
C
87
87
87
Shorts across
relay/
stabilising
resistors
43
87 Generator differential r
A Ammeter
A
Primar
y
injectio
250V n
A.C. test
set
suppl
y
Temporary
short
circuit
B
C
Bias
coils
Operatin
g
coils
44
87
87
87
Temporary
short
circuit
A
B
Primary
injection
test set
250V
A.C.
suppl
y
C
Bias
coils
Operatin
g
coils
45
87
87
87
Generato
r
~
Bias
coils
87 87 87
Operating
coils
Primary
injection
test set
A
B
C
64
250V A.C.
supply
Temporary short
circuit
Primary
injection
test set
A
B
C
A
48
64
B C
Temporary
short circuit
Filter
network
46
Primary
injection
test set
49
>
250V
A.C.
supply
Commissioning & Maintenance of Protective Relays
20 19 18
17 16 15
6
A
50
14
13 12 11
7
B
8
C
9
N
10
B
C
Primary
injection
test set
B
OP
51
Pilots to
remote
end relay
OP Relay operating coil
B
OP
B
Relay bias coil
OP Relay operating
coil
A
Ammeter
A
Primary
injection
test set
52
Pilots to
remote
end relay
250V A.C. supply
A
C
C
Feede
r
Instantaneous current
distribution of three-phase
balanced load with
phase A current at
B
maximum
B
OP
OP
Pilots
53
Short-Circuiting Connections
on Test Plug for Load Test
Short circuiting connections
on rear of test plug
20 19 18
To relay summation CT
17 16 15
A A
14 13
7
B
12
8
C
9
N
To main current
transformers
54
A1
250V
A.C.
supply
A2
Primary
injection
test set
A1 and A2
87
relay
95
95X
circuiting
55
Ammeters
Busbar Protection
Supervision relay
Bus wires shortrelay
Test
links
A
B
C
N
Zone
bus
wires
95
87
87
87
95
X
A
Ammeter
Busbar ProtectionC
relay
95 Supervision relay
95X Bus wires shortcircuiting relay
250V
A.C.
supply
Tes
t
link
s
Primary
injection
test set
A
B
C
N
95
X
95
56
87
87
87
Zone
bus
wires
Test circuit
Temporar
y
short
circuit
57
Primary
injection
test set
A
A
B
C
N
A1
A2
87
95
95X
Test
link
s
A2
95X
87
87
87
A2
A2
Zon
e
bus
wire
s
A
250V
A.C.
supply
Primary
injection
test set
Test
links
A
B
C
N
58
95
X
95
87
87
87
Zone
bus
wires
Stability Test
A
B
C
Test
plug
Overcurrent
test set
250V
A.C. supply
Pilots
B
OP
OP
59
Test
plug