Do you always pull circuit breaker arc chutes?

[wrh9278]

When maintenance testing breakers how often do you pull the arc chutes to inspect the main contacts? Some guys say you should always pull them, others say its not necessary if contact resistance is good, especially if they are difficult to remove.

[lester mcmanaway]

When maintenance testing breakers how often do you pull the arc chutes to inspect the main contacts? Some guys say you should always pull them, others say its not necessary if contact resistance is good, especially if they are difficult to remove.

We do every time just to do a visual inspection. You would not believe how many times we've opened up a breaker and found loose hardware on a contact assembly or a missing contact pad on one of the arcing contacts etc. Im sure it varies upon job scope but i've never been on a job that we did not inspect the contacts.

[SecondGen]

Arc-chutes should always be removed. NETA maintenance specs say you should inspect circuit breaker moving and stationary contacts for condition, wear, and alignment. You should also inspect the individual arc-chutes for damage or signs of excessive arcing.

If you really want to go by the book you should also verify that primary and secondary contact wipe and other dimensions vital to satisfactory operation of the breaker are correct. These might include sequence and pressure checks.

[johnnygleason]

When maintenance testing breakers how often do you pull the arc chutes to inspect the main contacts? Some guys say you should always pull them, others say its not necessary if contact resistance is good, especially if they are difficult to remove.

How do you perform a slow close test with out removing the arc shoots? I would refer back to the manual of the breaker, and it will give you step by step on how they would perform their own maintenance