Hot Breaker

[bgmac]

Just moved into to a new house and upgraded the main panel to 200 amp service from 150. Took the old breaker panel and installed it in my brew shed as a sub panel with 60 amp service. The old panel is a square D in good shape. I ran a small sub panel off the shed panel and installed a dedicated 30 amp GFCI breaker.

Ran a test run on my boil coil 5000 watt set up. The 30 amp breaker in the shed panel feeding the the dedicated 30 amp GFCI started getting fairly hot when running at 100% to the boil coil. I put a temp gun on it and it was around 135F, air temp in the low 70s. The 30 amp gfci was around 100F.

So I swapped out the breaker since I have 3, 30 amp breakers from the old house panel. Ran it at 100% and it heated up to about 135F, just like the first one I tried. The 30 amp GFCI was around 100F.

Is that too hot? Or am I just being too cautious?

The first pic is the shed panel with the 30 amp breaker on the top left. The dedicated 30 amp GFCI panel.

 

[mabrungard]

Loose terminals are a frequent source of resistance and heat production. Torque screw terminals and make sure that clip in connection surfaces are not oxidized. Use a conductive paste to help.

 

[bgmac]

Loose terminals are a frequent source of resistance and heat production. Torque screw terminals and make sure that clip in connection surfaces are not oxidized. Use a conductive paste to help.

Thanks, I torqued the screws when I installed the breaker as tight as I could. The conductive paste is a good idea.

 

[itsnotrequired]

while 135 is pretty warm, it is within the breaker spec, especially when operating for an extended period of time near maximum rating. the terminations should be cooler than the breaker, however.

 

[bgmac]

while 135 is pretty warm, it is within the breaker spec, especially when operating for an extended period of time near maximum rating. the terminations should be cooler than the breaker, however.

That's good to know. I am still not comfortable with the heat. I think I am going to install 6 AWG wire and a 50 amp breaker from the shed panel feeding the 30 amp GFCI panel.

 

[itsnotrequired]

That's good to know. I am still not comfortable with the heat. I think I am going to install 6 AWG wire and a 50 amp breaker from the shed panel feeding the 30 amp GFCI panel.

before going to that expense, you may want to consider replacing the standard 30 amp breaker first. manufacturing tolerances, age, etc. all contribute to how hot a breaker can get and the temperature difference between two different breakers operating at the same amperage can be significant. a 30 amp 2-pole breaker is, what, $10? $15? might be a worthwhile "bet" to see if it gets you a lower temp.

 

[rburrelli]

Thanks, I torqued the screws when I installed the breaker as tight as I could. The conductive paste is a good idea.

Are you using 10 gauge wire?

 

[day_trippr]

The jacket color indicates 10 gauge Romex...

Cheers!

 

[rburrelli]

The jacket color indicates 10 gauge Romex...

Cheers!

Sorry. I never looked at the pictures. Orange jacket indicates 10 gauge.