480 volt breaker failure.

[edko]

A 480 volt breaker has failed several times and has been replaced. It is tied to a pump. What is general root causes of several breaker failures over time at this low voltage?

 

[ScottyUK]

Another candidate for the most badly presented question of the month. How the hell are we supposed to know from the information you haven't presented?

What is the failure mode? What type is the breaker - MCCB or ACB? Which manufacturer? What model and size is the breaker? Have you opened the breaker up? Post some photographs.


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

 

[EEJaime]

Just the month?

 

[Zogzog]

Too much current for too long a time combined with a lack of maintenance.

Hows that for a generic answer?

 

[jraef]

I'll add:
How many is "several" and how long in between each failure.

edko,
Forgive ScottyUK's harsh tone, he's a good guy gone bad

To get the best help in this forum, it's a good idea to post details rather than generalities. There are a lot of very smart and experienced people participating, but none of us are mind readers (well, MOST of us are not anyway). Part numbers or series descriptions are even OK, you don't need to worry about hurting anyone's feelings (as you can tell, we don't).


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[trosepe]

edco,
More information would definitly be helpful but if we assume this is a molded case circuit breaker; excessive heat is a typical cause for circuit breaker failure. The circuit breaker is heated from the load current, which on pumps is usually continuous. If the circuit breaker is in a high ambient environment, this additional heat can result in reduced life and early failures. The typical failure is heat related nuisance tripping or contact failure due to high contact resistance that develops due to the high temp. Come back with some more information as was so gently suggested by the other members and you will get some excellent help.

 

[ScottyUK]

jraef,

thread237-247469, first reply.

Touche!


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