I have pointed this out but the client is adamant that since its only a temporary measure we should not spent money on it. There is a diff circuit with a 4C21 relay which require similar step up interposing CT's on the HV and LV side, but the connections were straight forward.
Somehow the current arrangement was missed out when I uploaded the proposed arrangement. I have added the current arrangement below.http://files.engineering.com/getfile.aspx?folder=36dfa819-58b0-4f11-a075-eb7854c3e125&file=Current_arrangement.pdf
I am working on modification of protection system to suit a temporary transformer. Initially the system was designed for a 60MVA 132/33kv YNynd11 and A CDG66 O/C relay with a MCAG 14 REF relay are installed on the 132kV side. Main CTR = 500/1 connected in Y configuration. OC set at 0.75A i.e...
Yes,you are right about the 1.5% of In. And truely, the In is stated as 1A on the ralay facia. I still am worried about this pick-up setting because the feeder being protected by the relay has a cable about 2.5km long and the charging current should be tripping this feeder constantly. There is...
The inrush current is a result of magnetic field build up in the primary winding of the transformer and will be high depending on the switching point. You would expect the worst case to be 12 times the primary full load current for about 100ms even when there is no load on the secondary.
The...
I came across an MCSU relay(GEC) setting which puzzled me. The Core balance CT ratio is 0.5/0.0075 and the pick up was set at 1.5 with a plug setting of 1. What is the actual primary pick-up current in this case?
I thought it would be 1.5x CTR(66.67)= 100A, but the source of the feeder where...
Thanks Davidbeach, I was trying to avoid the process of fitting new relays on site, slotting holes on the new panels etc. It seems there is no way out other than the Zero sequency CT method.Which relay would be most suitable? Should I sue the Startco as on the 3.3kV side ( see below)...
I want to detect a 2 Amp Primary SEF on an isolated 3 phase underground circuit. My primary current will be around 700-800 amps maximum when starting a series of water pumps. There is a requirement that the SEF at the 11kV outgoing feeder towards the Pump Station should be limited to 2 Amps. I...
