inspection question

[cda]

From non electrical inspector type person

If circuit breakers are warm to the touch, Problem?????

if yes:

Should electrican be required to check them

 

[480sparky]

Heat is a natural by-product of current flow. Every component of every electrical system will increase in temperature when current flows. It is a fact of life, just like paying taxes and dying.

If it's just warm to the touch, take an amp reading before going bonkers about it. If it's blistering hot, then have it checked out.

 

[raider1]

I agree with 480sparky,

A breaker that is warm to the touch most likely will be operating within its range.

Take an amp reading on the branch circuit conductor connected to the breaker and see what the load is.

Breakers that have a continuous load at 80% of the breakers rating would cause the breaker to feel warm to the touch.

Breakers that are hot to the touch should be checked out.

Chris

 

[Bryan Holland]

From UL 489:

Temperature Testing The UL 489 Standard allows for two types of

ratings. Standard circuit breakers cannot exceed

a maximum of 50°C temperature rise at the wire

terminal connection at 100%current in 40°C open

air. 100% rated circuit breakers may have a

temperature rise of 60°C at the wire terminal

connection in the smallest allowable enclosure if

the circuit breakers are connected with wire rated

at 90°C wiring insulation sized to the 75°C chart

(Table 310-16, National Electric Code®—NEC®).

The ANSI C37 Standard requires a maximum of

55°C temperature rise at 100% in the smallest

enclosure and a maximum of 85°C temperature

rise on the contacts.

 

[cda]

Thanks had an incident awhile back, where the panel was very hot and the lights kept going off.

So a little more concerned with warm panels

 

[Span]

I e-mail Murray for answers, they e-mail back and told me " AFCI insind contain sensor coil, it will emit low humming sound and working temps would reach 140 F.

For cda, your panel breaker seat might be damaged by constant overload, and breaker contact metal loose it gripping strenth and cause bad connection to generate heat.

span