GE Electromechanical Relay

[Pam60]

Hi,

I am sure you have seen it and done it all. I am not used to electromechanical relays and had my first encounter with them recently. I have a GE PJC32 relay

http://www.gedigitalenergy.com/app/ViewFiles.aspx?prod=pjc&type=3

It is a instantenous relay with a curve charc. Customer has a 250E fuse which does not seem to be coordinating with this 4800A Inst. OC setting. Could you kindly suggest me any other option interms of electromechanical relay may be Extremely or Very inverse which could replace my Inst O/C relay and still serve the same purpose by providing coordination betweek fuse and O/C relay.

Thanks

 

[alehman]

GE has several electromechanical time-overcurrent relays. Some have optional instantaneous elements as well. You might try an extremely inverse time characteristic such as the IFC77.

http://www.gedigitalenergy.com/multilin/catalog/ifc.htm

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[racobb]

Yes it has a curve, but I expect it will not coordinate with a 250 amp fuse....it is just to fast. I usually expect that there will be no time coordination with the instantaneous relay, ie: if it can "see" the fault current, it will operate irregardless of whether or not a downstream device does as well.

One question would be, do you have other time overcurrent protection installed, and if so do you really need the PJC.

As alehman says you could substitute another relay such as a 77 or slower. If your PJC is in an S1 case, then any GE IAC relay designed for the S1 case (as most of their old overcurrent relays are) will slide in. You may need to do some minor wiring on the case to get the time overcurrent output hooked up though.

Alan