Is this a normal breaker or an AFCI or GFCI breaker?
It could be an AFCI. In which case there could be a loose connection that is arcing.

 

Just a normal breaker. I'll check the connections to see if it's a loose wire. Thanks.

 

That is a hint that the breaker is getting ready to retire.

More than likely this is happening when the ambient temperature is changing, Temperature changes causes things to expand or contract by just a tiny bit, but the expansion / contraction is enough to cause the catch in the breaker to release.

Get a replacement breaker and change this old one, then see if it continues to happen.

On a side note, I have bought new breakers, that some "lowlife" had switched the new one in the box for their old wore-out one and stolen it.

So make sure that the one in the box is actually the correct brand, and looks unused before you but it.

I had to return to a store, and get accused of trying to cheat them, and swear that the one that I was trying to return was actually the one that I bought.

A real hassle, but I got a replacement.


ED

 

If it's a regular breaker then you have a fault or overload on the circuit.

 

Thanks for all the advice. Will be looking into it this weekend... Thanks.

 

DITTO !
How much power is this breaker carrying ?
it could be close to maximum
in which case the answer is clear

 

3 things cause CBs to trip

Over load
fault
Defective CB, random tripping if the load is consistent is MOST LIKELY a defective CB.

AS an electrician I would perform several test to isolate the issue, and we do not reset, reset reset not a wise move. The easiest thing you can do it feel the CB after it trips, is it warm?

Typically a fault will either escalate and the CB would continuously trip upon turning on or the fault would burn open and the CB would reset but you would have a partial outage.

If warm it is either an overload or defective CB.

 

My suggestion is to go buy a amp reader tool at Home Depot or Lowes. Get an amp load on that breaker and see how much it is drawing. Check the wire size on that breaker..ex..14gauge wire should be on 15amp and 12gauge wire should be on a 20amp.

 

I would just change the circuit breaker. If it is old, it may be failing.

I had a client several weeks ago who called about her microwave oven always tripping her circuit breaker. This was her second microwave oven that had this problem. She replaced her first one thinking that was the issue. I checked the load and it was not pulling enough amps to trip a 20 amp circuit breaker. I opened up the outlets on that circuit and found everything to be okay, but I replaced the GFCI and regular receptacles just to be sure. I also replaced the circuit breaker. Everything has been fine since.

You can put an ammeter on the circuit to see how much current is flowing.

 

Changed out the CB this weekend and everything seems to be working just fine now. Thanks for all the advice....