GE electromechanical relays - prone to dropping flag from vibration 2

[electricpete]

For Westinghouse electromechanical relays, the flag drops easily due to vibration.

Can the same thing happen for GE electromechanical relays?

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(2B)+(2B)' ?

 

[davidbeach]

Yes.

 

[electricpete]

Thanks. I am curious why you say that.

I looked at one and had a hard time understanding how that could happen. Unlike the Westinghouse where flag moves down, the GE flag must move up.... and the only thing that pushes it up is the contact arm. Contact arm I believe is balanced in such a manner as to be not susceptible to vibration (to avoid sensitivity to spurious trip). I was unable to cause flag the contact arm to move, much less flag to drop during my attempts at mechanical agitation with relay on the bench.

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(2B)+(2B)' ?

 

[electricpete]

correction:

I was unable to cause flag the contact arm to move, much less flag to drop during my attempts at mechanical agitation with relay on the bench.

should've been:

I was unable to cause the contact arm to move, much less flag to drop during my attempts at mechanical agitation with relay on the bench.

=====================================
(2B)+(2B)' ?

 

[davidbeach]

Well, maybe not the flag itself per se, but the instantaneous element of an IAC will operate on vibration, and that certainly sets the flag.

 

[cranky108]

Some of the relays the contacts moves sideways which have been known to cause trips. This is a common known problem with em relays.

 

[gattie]

Switchgear or MCC panel vibration can cause protection aux trip relay flags to unlatch & initiate a false trip.
I've experienced this on a large MV Fan Motor starter where the fan
was located adjacent to the MCC room.
During startup, as the fan accelerated through its critical speed, the panel vibrated in sympathy causing the relay to unlatch.
Problem was solved by mounting the relay housing on rubber pads.
It was a vintage GEC electromechanical motor protection relay.

 

[cranky108]

Sort of brings a new meaning to "shake things up", and "in the dark".