MCCB Failure Info
MCCB Failure Info
(OP)
I am new to the maintenance side of power systems and I'm trying to learn some quick steps for troubleshooting MCCB failures, i.e. square d 2000 RK1 failure. I'm trying to determine what could be the causes of this breaker failure. Any help is appreciated!





RE: MCCB Failure Info
RE: MCCB Failure Info
Thanks,
OmgVlt
RE: MCCB Failure Info
Why are you calling it a Breaker Failure if it Tripped? It looks like it is locked out, can you inspect it for damage and describe what you find. Do you have the manual or can you download one from the OME? What kind of loads are downstream?
Chuck
RE: MCCB Failure Info
eg:
Ground faul tcurrent?
Overcurrent?
Overload?
Under voltage shunt trip?
External tripping circuits?
Was the proper reseting procedure followed?
I have seen an operator unable to reset a breaker because he did not apply enough force to the handle to reset the breaker.
Bill
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"Why not the best?"
Jimmy Carter
RE: MCCB Failure Info
"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic ù and this we know it is, for certain ù then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". û Nikola Tesla
RE: MCCB Failure Info
Based on your explanation, would it be accurate to suggest that the fault occurred on the line side of the device because the breaker would not reset when the load was removed? However, the original breaker closed without incident prior to being tested.
Thanks,
OmgVlt
RE: MCCB Failure Info
I get the impression you're aware of this constraint, but your operators may not have been.
RE: MCCB Failure Info
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: MCCB Failure Info
RE: MCCB Failure Info
RE: MCCB Failure Info
I work with these Schneider breakers on a regular basis. Often after they trip, they will not reset due to the trip coil not latching, especially those breakers used in dusty conditions. I have removed and cleaned the trip coils before and got them to reset.
If you look at the top of the trip unit, right below where it says "Micrologic 6.0", there is a row of lights. After a trip, one of the lights will be illuminated indicating the cause (assuming the internal battery is good). This should be noted by the operator in the event of a trip.