Temperature on main

The temperature on all the branch breakers was around 80 degrees. Temperature on the main was 125. What do you think?


Interesting - I don’t know the answer, but if you don’t mind I would like to put out some thoughts hoping to learn a little something…

Was any or all of these apparent: air conditioner/dryer/freezer/heating system/pumps in use, or heavy use on multiple branch circuits? Was the 80 degrees near the ambient temperature? (I really don’t know how HI’s do inspections in less than three hours when we look at such detail…) As you must know, friction at the junction of the breaker to the buss will generate some heat - so how much is normal? I look forward to some good answers coming down the net (internet.) Thanks for your post.

I think, if there were no apparent “issues,” I wouldn’t have even checked its temp. I also don’t think that 125 degrees is unreasonable.

Hi to all,

Cal, here is my rule of thumb, standard breakers more than 10 degrees about the median bother me, AFCI & GFCI breakers more than 20 degrees above the median bother me. Any breaker running 45 degrees above the median would seriously bother me to the point I would be calling for an electrician to strip down the panel to figure out why.

It could be caused by any of the following:

  • Bad main breaker
  • Loose Service connections
  • Poor Bus attatchments
    None of the above are good, I would have it evaluated.



I normally scan the breakers with my laser thermometer just because… In this case, I could feel the difference in temperature on the panel cover. The ambient temperature was 75 or so. The top two breakers were 40 amp and a little warmer, around 90. The main was the one that stood out. I think getting a pro to check is the best answer. I know I wouldn’t be comfortable without at a minimum an OK from a pro.

Safe move. I would as well.