When should circuit breaker contacts be lubricated?

[zofofg]

I am new in this industry but am questioning an answer i got wrong on the practice test.


Generally, when should circuit breaker contacts be lubricated?
Your Answer: Circuit breaker contacts should not be lubricated.


Obviously you see my answer of "contacts should not be lubricated", could this question be about hinge points that you would oil/lubricate. I asked a Level III I work with and he has never heard of lubricating the actual contacts. Does anyone have any clarification. Thanks in advance

[SecondGen]

Circuit breaker contacts usually should not be lubricated. The heat from the current flow through the contacts breaks the lubricant down and causes contact resistance to increase. With that said, some manufacturers might recommend it.

Check out this thread for more info -> http://testguy.net/threads/10-Do-You-Ever-Grease-CB-Contacts



I asked a Level III I work with and he has never heard of lubricating the actual contacts.

[hy3533]

i got this question wrong also. what is the correct answer?

[zofofg]

Thank You secondGen

[zofofg]

i got this question wrong also. what is the correct answer?

Answer is only in corrosive atmosphere

[SecondGen]

There is a lot of confusion around this question so hopefully this can add some insight to my previous post. I found this little blurb noteworthy from Square D regarding lubrication, with the key point being that lubricants also prevent corrosion:


The function of a lubricant is simple - reduce friction between moving metal surfaces. A lubricant coats surfaces and resists being displaced by pressure, keeping the metal parts separated. Lubricants also prevent corrosion, block contaminants and can serve as a coolant. A good lubricant flows easily under pressure and remains in contact with moving surfaces. It does not leak out from gravitational or centrifugal forces, nor does it stiffen in cold temperatures.

I said before that circuit breaker contacts usually should not be lubricated because it can increase resistance, which is still true, but sometimes lightly lubricating the main contacts with an approved lubricant can guard against corrosion. It all depends on the environment, like a chemical plant for instance.



Answer is only in corrosive atmosphere


Happy to help, zofofg.


Thank You secondGen

[Xjaime83]

thanks this was helpful

[Ronwilson1801]

I am new in this industry but am questioning an answer i got wrong on the practice test.



Obviously you see my answer of "contacts should not be lubricated", could this question be about hinge points that you would oil/lubricate. I asked a Level III I work with and he has never heard of lubricating the actual contacts. Does anyone have any clarification. Thanks in advance

You apply grease to the contacts no lubrication.