Cable reaches 120 F - OK?

Rick Danya

I have a 100 amp breaker panel feeding an electric furnace through ~ 30 feet of aluminum cable specified as "PRIORITY 3C 2AWG AA8000 1C 4AWG AA8000 TYPE SE STYLE R XHHW-2 600V XIPE (UL) 2008 05323 FT".

When the furnace is running, the outside jacket of the cable reaches 120 degrees F. Is this indicative of a problem? From what I've been able to look up on the cable I believe it is OK for the 100 amp service.

Any advice is appreciated.

Stubbie

I hope that breaker panel is dedicated to the furnace and is fed from service equipment panel that is 200 amps or so.

That temp. is not excessive XHHW-2 is rated 90C or 194F

The wire size would suggest a amperage requirement of the furnace to be in excess of 65 amps.

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Stubbie

Rick Danya

Thanks for the quick reply. The breaker panel is dedicated to the furnace and it's connected directly to the meter as a separate 100 amp service.

The furnace manual says the max current draw could be 97 amps. It's a 22.5KW unit.

mpoulton

#2 Aluminum XHHW-2 is good for 100A if the equipment is rated for 90*C terminations. Which it's almost certainly not. So it's good for 90A. The furnace is a bit of an overload for that cable in that installation, but I would not change it.

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rrolleston

I also agree with mpoulton but you could always get someone in there to check to make sure all the connections are good and maybe check how much it's drawing. Just a few bucks to have the extra insurance that everything is checked over and OK.

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