RTCC means relay tap changer circuit,these are the relays
which give command to the tap changer present in the
transformer H.T side to either increse or decrese the tap
since due to inductive load ( lagging p.f ) , the secondary
terminal voltage would decrease which would not be good for
the loads so by chnging taps, we increase the primary
voltage which in turn changes the secondary
voltage,normally done online.
According to primary voltage variation, the RTCC gives
command to the on load tap changer which is provided in
transformer L.T side (i.e consumer side) to either increse
or decrese the L.T voltage to optain normal working voltage
to the consumer.
Tap changer should connect only in transformer consumer
side. Because the HT side line connected with main grid. So
we can not change the grid voltage.
RTCC panel is called as the Remote Tap Changer Circuit. it
is used to control the OLTC Tap changer from the control
room or control point itself where RTCC panel is Placed. it
is used to get the stable output voltage.
RTCC MEANS REMOTE TAP CHANGING CIRCUIT. AND REQUIRED FOR
CHANGING THE TAP AT THE HV SIDE OF THE TRANSFORMER ONLINE
IF THE LV SIDE VOLTAGE OF THE TRANSFORMER FLUCTUATE
BEACAUSE OF LOAD. IT HAS AVR (AUTOMATIC VOLTAGE REGULATOR)
TO CONTROL THE TAP CHANGING.
Just a silly question but just to make my curious mind bac
to normal - Why was not 67 and 67N
relays built into a single relay as i have noticed that the
R,Y,B CT wiring end up into the 67 relay
while the common of the R,Y,B CT wiring end up into the 67N
relay. Then it was better if a single relay was manufactured
just like the distance relay (21). Another question i would
like to ask is - how do we know where the 67 and 67 N
relay has to be placed.why is it not placed at the
transformer bay? In the substaion that i am working -i have
noticed that it is placed between a breaker and
a common double bus bar and this line bay is connected to
another substation at a remote place which is furthur
connected to a load.
S______CT for 67 & 67N ______Breaker _____ remot s/s.