I just had 2 of these 30 amp 240 volt lines with 10 gauge wiring installed and running the APC 9571 PDU on each of them. This past weekend when the temperatures got in the 80s the circuit breakers got really warm (I could still hold my hand to them, but barely) to the touch and the plugs at the wall were each very warm. Should I be worried about this? I can't imagine what will happen when the temps get up to 100 degrees. Now that it's cooled off again everything is nice and cool. I'm running 19 amps on each one.
19amps? as in you measured it?
Also, What does the outdoor temp matter? Do you not air condition your house?
Yes I measured it with one of those things with a claw that goes over the wire and tells you the amperage. The fuse box is outside and I set the AC to 85. How does any of this help answer my question?
Wire and breakers will get warm when running large current(proportionate to their diameter) even within the range that is considered safe or acceptable.
If wire is running in an unconditioned space, and is subject to high ambient temperature, then it should be derated in addition to the derating for a constant load.
The wire in normal conditions is rated for 30amp, derated 20 percent for constant load is 24amp if your setup is properly installed, not exposed to excessive ambient temperature and your reading of 19amps is accurate, then it would be my opinion that it is probably ok, your idea of warm could be different than mine.
The best advice that I can give without actually looking at it myself would be that if it concerns you, call your electrician back over on a warm day. A service call is a very inexpensive piece of mind.
