Overheating breakers

[Dcash]

I have an issue with some lighting breakers. They are 3 pole breakers (20 amp), square D. These breakers are hot to the touch. Not alarmingly, but approx 100-106 degrees F. The client is very concerned about this, and even though derating is correct, wire sizes are correct, terminals are tight, and amp reading are between 12-14 amps, these breakers continue to be warmer than what I'm used to. The lighting load is T-5 fluorescents, 6-lamp. I haven't had this particular situation happen before. One or two circuits yes, but never EVERY breaker for all lights be this warm. Suggestions in case I'm missing something would be helpful. Thank you.

 

[jrlelectric]

overheating breakers

overheating breakers

We have been in the business of selling and reconditioning circuit breakers since 1985.
I AM NOT AN ELECTRAL CONTRACTOR and always suggest contacting a liceinced electrician.

If your circuit breakers all are hotter than normal, it may be the incoming connections to the bussbar. If it all breakers, it may be the ambient temperature outside.
if it is the circuit breakers themselves, the only place they can get hot is
1- loose connection from the bussbar to the breaker
2- loose connection from the wire to the lug of breaker
3- the internal contacts are pitted or have a buildup of residue.

If it is all breakers, my assumption is the climate temperature. To know for sure you can have infrared testing to determine where the heat is building up.
If you tell me what type of breakers these are, I can probably get you the internal pictures and trip curves.

Sincerely, Joe

 

[petersonra]

I have an issue with some lighting breakers. They are 3 pole breakers (20 amp), square D. These breakers are hot to the touch. Not alarmingly, but approx 100-106 degrees F. The client is very concerned about this, and even though derating is correct, wire sizes are correct, terminals are tight, and amp reading are between 12-14 amps, these breakers continue to be warmer than what I'm used to. The lighting load is T-5 fluorescents, 6-lamp. I haven't had this particular situation happen before. One or two circuits yes, but never EVERY breaker for all lights be this warm. Suggestions in case I'm missing something would be helpful. Thank you.

They should be warm to the touch if they are seeing a regular diet of 12-14 Amps, especially if it is a fairly warm area.

 

[don_resqcapt19]

That temperature is well within the permitted temperature rise for a breaker.

 

[JFletcher]

What is your ambient temp? If every breaker is carrying a moderate load like that, they are going to be warmer than a panel where half the circuits are unloaded/lightly loaded. If every breaker is carrying 12-14A, multiplied by 42 spaces, that's a problem for a 225 (or even 400A) panel.

Welcome to the forum.

 

[jim dungar]

That temperature is well within the permitted temperature rise for a breaker.

Absolutely.

Surface temperatures in excess of 104F are not uncommon at all for electrical equipment. Sometimes it seem that the handles, on devices, are the hottest areas, maybe they are used as heat sinks in order to help keep the terminal 'cool'.