GEC CDG 34 Electromechanical Relay

[eti]

Hi

I have a one off GEC CDG 34 relay to test, a legacy relay left on a fairly new system, it protects an 11kV transformer feeder. The remainder of the relays are modern digital type.

Can anyone suggest a suitable secondary test set for the high currents involevd?

 

[JG2828]

I can't find the manual for the CDG 34. How much current do you need and do you need single or three phase?

 

[eti]

JG, I need three phase. Not sure what current, I'll have details of the CT's etc tomorrow.

 

[ScottyUK]

Probably a 5A relay - most decent test sets should be able to source that current. Or is there something unusual about this one?


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[ScottyUK]

Oh, and the CDG 34 is composed of three single-phase relays which could be 3 identical O/C elements, or 2 O/C elements plus a third designed for use in the residual connection of a balanced set as an E/F element. You should be able to test them independently of each other using a single phase set.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[DTR2011]

these relays have very high burdens. If you are using a modern relay test kit, make sure to use a mode that has the highest compliance voltage.

 

[eti]

Dear all


Thank you for the advice. Scotty, there is a CDG14 protecting the same feeder for earth fault, so the CDG34 is probably only doing overcurrent. I've confirmed it's a 5A relay, so a fairly high burden. The sverker unit we have will probably be ok, it can deliver up to 50 single phase with the elements linked out.

Thanks all.

eti