Conduit with 60 amp service getting warm

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Old 09-07-19, 03:14 PM
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Conduit with 60 amp service getting warm

I completed the Tesla Wall charger installation. Thanks for everyone's help on this forum.

Interesting to observe that conduit actually gets warm. 60A circuit breaker even slightly hot when touched on front. Assuming this is expected?

I used 3/4" EMT conduit, 6AWG hots and 8AWG ground. Car can charge max at 48A
 
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Old 09-07-19, 03:31 PM
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You're ok. You're limited to four #6 wires in a 3/4" conduit.
 
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Old 09-07-19, 03:40 PM
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Took out a simple IR thermometer. The breaker was at 40C
 
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Old 09-08-19, 05:32 AM
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Also, I fed the stranded wire directly into breaker terminal. Should I use crimp?
 
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Old 09-08-19, 06:10 AM
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No need for a crimp. .
 
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Old 09-08-19, 07:56 AM
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Most home breakers have a thermal element that is responsible for small overloads. This will warm the breaker a bit. Also, the wire screws have a torque spec that should be followed. They are to be surprisingly tight.
 
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Old 09-12-19, 05:10 PM
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I conducted some additional measurements with my IR thermometer.
I was somewhat surprised that there is a significant temperature difference between the two breakers of my 60A breaker assembly.
The one at the bottom gets to about 35C; the one on top 45C. I would expect top to be a bit hotter as heat raises, but 10C ??
 
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Old 09-13-19, 03:14 AM
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There is a lot of current going through the conductors. It is not surprising that the pipe is getting warm when the charger is at full load.

At 45C the breaker is within the rating of the breaker and terminals. Most newer breakers are rated at 60C or 75C.
 
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Old 09-13-19, 04:20 PM
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I guess my surprise is that the one of the breakers of my dual pole gets much warmer than other.
 
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Old 09-14-19, 05:42 AM
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Is the conduit uniformly warm over its entire length or just at the ends?

If one half of the two pole breaker is somewhat warmer than the other, the breaker unit could be worn out or defective, with a loose connection inside. Or somehow the load out of that half of the breaker is greater, which would only occur if there was some 120 volt usage on the branch circuit.

Double check tightness of the terminal screws on the breakers (actually for all breakers and set screws in the panel) But do not use stupendous strength that could strip the screw threads.
 
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Old 09-14-19, 06:54 AM
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The conduit is evenly warm over the entire length.
I will double-check the terminal screws.
The breaker is brand new..... (Siemens Siemens Q260)
 
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