RTCC Avr
RTCC Avr
RTCC Avr
PANEL
RTCC is Remote Tap Changer Control which is a Programmable device to
control the output of the transformer through OLTC unit fitted in the transformer
through control cables. The desired voltage will be achieved accordingly by
controlling the OLTC with respect to the tap position through RTCC system. The
output voltage of the transformer is been maintained through an inbuilt AVR
(Automatic Voltage Regulator), which continuously verifies the output power with
the set / programmed reference voltage, which triggers the OLTC accordingly.
Hence, by above said phenomena, the consistency of the transformer output is
been maintained.
RTCC is a panel consisting of the AVR, Display for Tap Position, Voltage, LEDs
for Raise & Lower of Taps relays, Selector Switches for Auto Manual Selection
etc. In AUTO Mode the voltage is controlled by the AVR. In MANUAL Mode the
operator can
Increase / decrease the voltage by changing the Taps manually through the Push
Button in the RTCC. Normally RTCC panel will be installed in Main panel room
and will be connected to OLTC (On load tap changer) of the transformer through
control cable. There will be AVR in RTCC Panel to control the secondary voltage
of the transformer and AVR output will control OLTC motor in Clock wise or
Anti clock wise directions.
RTCC is installed with transformer HT Panel. Automatic OLTC Panel consists of
a LCP and a RTCC. System uses an AVR (AVR-MA9) to sense the LV Voltage
and a comparator circuit to compare the sensing voltage with a preset value. Any
difference in two sends a corresponding signal to OLTC Panel to lower or raise the
LV Voltage of transformer. The OLTC Control Panel also has a provision to
operate two or more transformer in parallel. One transformer is taken as the master
and the remaining as followers so that they follow the Masters LV Voltage set
values.
On load Tap Changer (OLTC) is used with higher capacity transformers where
HT side voltage variation is frequent and a nearly constant LT is required. OLTC
is fitted with the transformer itself. Multiple tapings from HV windings are
brought to the OLTC chamber and connected to fixed contacts. Moving contacts
rotates with the help of rotating mechanism having a spindle. This spindle can be
rotated manually as well as electrically with a motor. Motor is connected in such a
way that it can rotate in both the directions so as to rotate the OLTC contacts in
clockwise and anti clock-wise direction. Two push buttons are fitted on the LCP
(local control panel) to rotate the motor and hence the OLTC contacts in clockwise
and anti-clockwise direction. This movement of contacts thus controls the output
LV voltage of the transformer. So rotating of OLTC contacts with spindle or push
buttons in this way is a manual process. In case this process of rotating the OLTC
contacts and hence controlling the LV side voltage is to be done automatically
then a RTCC (Remote Tap Changer Controller) is installed with the transformer
HT Panel. The RTCC sends signals to LCP and LCP in turn rotates the motor as
per the signals received from the RTCC.
Automatic OLTC Panel consists of a LCP & a RTCC. System uses an AVR
(AVR-MA9) to sense the LV voltage and a comparator circuit to compare the
sensing voltage with a preset value. Any difference in two sends a corresponding
signal to OLTC panel to lower or raise the LV voltage of transformer. The OLTC
control panel also has the provision to operate two or more transformers in
parallel. One transformer is taken as the master and the remaining as the followers
CHARACTERISTICS:
Wide Range
Voltage Class 11kv, 22kv, 33kv, 66kv and 132 neutral end
Current Rating up to 500 Amps
Single phase off circuit Tapchanger upto 2000 Amps
Type tested as per IS and IEC standards
Tapchangers for Furnace application
6, 9, 10,17, 21, positions
Suitable for bidirectional power flow
Supplied with Remote Tapchanger Control Cubicle
Compatible for SCADA and computer controls
RI
LI
AI
MI
UV
P
L
R
S
TIMER
L-SET
Raise Indicator
Lower Indicator
Auto Indicator
Manual Indicator
Under Voltage
Panel
Lower - Push
Raise - Push
Set
Time Delay Control
Lower Level Setting
Control
FEATURES:
power transformers with on-load tap changers. The bandwidth control allows the
dead band to be set in terms of raise and lower voltage limits around a particular
nominal value with specified sensitivity. The time delay control allows the
regulator to respond only to the voltage fluctuations lasting for periods greater
than the selected time delay. Where the voltage correction requires more than one
tap change, the time delay is re-initiated before further tap changes. No special
provision is required to reset the time delay, which resets automatically after the
voltage correction. Solid-state lamps (LEDs) indicate voltages outside the preset
limits and control relay operations. Operation of the raise/lower control relays is
automatically inhibited when the voltage falls below the specified undervoltage
limit/goes above the over voltage limit. One pair of normally open relay contacts
is provided to affect the tap changer raise and lower operations and to trigger an
alarm in case of under voltage/overvoltage conditions. An alarm in the form of
normally open contacts has been provided in the same cabinet in case of control
failure, i.e., AVR relay continuously showing either 'L' or 'R' command for more
than 15 minutes due to malfunctioning of AVR/OLTC/any other reason. An inbuilt tap position indicator is provided for indicating the tap number of power
transformer with 1 kW step resistances for a maximum of 35 taps. 4-20 mA TPI
output for Scada can be optionally provided in the same cabinet. For compensating
line resistance and reactance at different load currents an optional line drop
compensator can be provided in the same cabinet. An alarm in case of auxiliary
supply failure can also be provided in the form of normally close contacts in the
same cabinet.
6. LR Lamp
7. RR Lamp
8. CF Lamp
9. Test Lamp
set over voltage limit i.e. above 132V.this lamp will turn
off only when the PT Voltage falls below 127V.
On when Lower relay is energized.
On when Raise relay is energized.
On when Control fail Relay is energized i.e. when the PT
Voltage remains outside the bandwidth for more than 15
minutes.
ON when the AVR is in TEST Mode.
(B) CONTROLS
1. Power ON:This is a toggle switch which when ON supplies Auxiliary voltage to the
instrument.
2. R-Set:This is a variable control varying from 0.5V to 5.0V below NVA setting. This
control sets the lower limit of the PT Voltage below which if the voltage reduces,
then corrective action will be taken by the instrument. The setting is to be read on
display.
3. NOM Set:This is a variable control to set the nominal value of PT voltage varying between
10% of 110V.This setting becomes the reference level around which is to be read
on the display.
4. L Set:This is a variable control varying from 0.5V to 5.0V above NVA setting. This
control sets the upper limit of the PT Voltage below which if the voltage reduces,
then corrective action will be taken by the instrument. The setting is to be read on
display.
5. Time Delay:Corrective action takes place only after the time delay as set by the control has
elapsed and the PT Voltage continues to remain outside the set Lower or raise
limits (but does not fall below the UV/OV limit)
6. TEST/NORMAL Switch:It selects the test or normal mode of operation. In the TEST mode, PT voltage is
simulated internally and can be varied through the control on the front panel. A
LED indication is provided to indicate that the instrument is in test mode. In the
test mode the control relays are cutoff so that undesired operation OLTC is
prevented during testing. The voltage is monitored on the display in PTI/P
5. IC1 generates 15 minutes delay for CfR Condition which is indicated by CfR
LED.
6. When LDC option is required %R & %X compensation SW3 & SW4 allows for
polarity selection IC7 sums the PT I/P & LDC O/P.
7. TPI PCB: This PCB generates constant current which is used for generating
160mV per step. This IC2 is used to convert analog voltage to digital voltage and
display the same on 7 segment display.
UV Indication Permanently
ON.
PROBABLE CAUSES
Check Fuses Power On Switch connections to
rear panel termination block OK. Check Mains
Transformer and DC Voltages as per if faulty
replace main PCB.
Check PT Supply ,PT Fuse and Sense
Transformer if all are OK then check DO/P
Voltage TP9 on main PCB. If faulty replace
main PCB else replace Display PCB.
A to D Converter is faulty. Replace main PCB or
else Display PCB.
IC3 on Display is faulty. Replace Display PCB.
LINE DROP COMPENSATOR:Line drop compensators are used in load tap changing transformer and regulator
control circuits to maintain a predetermined voltage at some point downstream
from the regulated location. It is optional with Automatic voltage regulating relay
type EE-301 T. The option is housed in the same enclosure. The voltages at the
generating end and at the receiving end are not the same due to the drop across the
line. The LDC is used to compensate for this line drop and the amount of
compensation required is calculated as a% of the nominal voltage knowing the
length of the line, its resistance/unit length, its reactance/unit length and the rated
current and set on the front panel.
The line current is stepped down to 1A and fed to the LDC unit. The resistive and
reactive drops are simulated by having 90 phase shifted voltage and their polarity
is selected by polarity switches. The net compensation is then summed with the
stepped down PT Voltage.
CHARACTERISTICS OF THE REG-DA VOLTAGE REGULATOR: Large backlit LCD (128 x 128) with all important information (tap-changer
position,
voltage, etc.)
Measuring functions (U, I, P, Q, S, cos , , I sin , f )
Recorder functions (2-channel chart recorder)
Statistics functions (records total number of switching operations, switching
operations per tap)
Event recorder (log book)
Transformer monitoring functions incl. recording of the hot-spot temperature and
lifetime consumption
14 (26) freely programmable binary inputs 9 (21) freely programmable binary
outputs
Freely programmable analogue inputs or outputs (mA)
Pt 100 direct input for RTD temp. probe (option) Input for tap-potentiometer
(200...20k total resistance, option)
Control of three-winding transformers
Control of phase-shifting transformers
Limit value monitoring for all measurement quantities
4 freely programmable set-point values
Programmable rated values of U and I
Parametric software WinREG for setup, programming and display
as well as for PC-based archiving and evaluation of the recorder data
Simulation software REGSimTM for the simulation of any parallel operation,
network
and load situations
Implementation of freely programmable control tasks through
Peripheral bus RS 485 (COM3) for additional interface modules (ANA-D, BIND)
ParaGramer function for the display and automation of any parallel connections
with up to ten transformers
UL-certification
This is a modified version of earlier Microwarn 9600 model which has been
discontinued. Microwarn O600 is now more compact than before with reduced
depth. Also it can have 3 output relay for extra function. Microwarn 0600 consists
of 3 basic sections:
1. The Power Pack
2. The CPU
3. The Facia
1. The Power Pack:The Microwarn 0600 is powered by a highly reliable and noise free, specially
designed power supply. It converts the available power source (AC/DC voltage
supply) into a regulated and filtered DC output, which is fed to the annunciator
unit.
2. The CPU:This is the Central Processing Unit of Microwarn 0600 which scans and
processes the incoming fault signals from the various potential free field
contacts and drives the corresponding LED windows and the audible devices in
order to announce the fault, according to the operating sequence selected.
3. The Facia:This section consists of facia windows illuminated by Super Bright LEDs on
occurrence of any fault. The Super Bright LEDs ensure a long and absolutely
maintenance free window life along with a good visibility, and have very low
power consumption.NO/NC, T/NT or sequence selection DIP switches are
located outside, hence programming is now possible without opening the
Operational Temp.
Power Consumption
Optional
Dimensions (mm)
: 153 x 203
Panel Cutout (L x W)
: 166 x 216 x 82
Overall (L x W x D)
Wherever not specified Contact Rating: 5A @ 230 V AC (resistive) * CE marked
products available on request.
CONNECTION DIAGRAM:-
Dimensional Details