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Hello, I'm installing a Kohler steam generator and the plate on the generator specifies 8 gauge wire. I'm puzzled by that because I would expect the distance from the breaker panel to dictate the size of the wire.


If I use a wire gauge calculator with the other specs on the plate (240V, 45A, 1 phase), the calculators suggest using 6 gauge wire. I haven't done the exact measurement yet, but I'm guessing that I'll need to run the wire about 100 to 150 feet to get to the circuit breaker panel.



Does anyone know why they're specifying the wire size and what value that has to me? I assume I need to use 6 gauge for my installation.



Thanks!
dwaun
 

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Hello, I'm installing a Kohler steam generator and the plate on the generator specifies 8 gauge wire. I'm puzzled by that because I would expect the distance from the breaker panel to dictate the size of the wire.
The required gauge is based on ampacity, the current carrying capability of the wire. The distance is a separate issue. Longer runs will sometimes require a larger conductor to minimize voltage drop.


Does anyone know why they're specifying the wire size and what value that has to me? I assume I need to use 6 gauge for my installation.
Different insulation types and cable configurations have different limits on the amount of current they may carry. An 8 gauge type NM cable (Romex) is limited to 40A, not sufficient for your application. You would need to use #6 if you chose to use NM. But 8 gauge copper SER or copper THHN are permitted to carry 50A which would be fine. That's mainly the reason for the discrepancy.

At the 150' distance you mentioned #6 copper would be preferred, but not completely necessary. The voltage drop with #8 would be around 4.5% which isn't great but nor is it intolerable to a heater. It's a moot point if you're using NM.
 

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Thanks for the comments.


I did forget to mention that they also have a note on the steam generator saying:

"Note: Use 60 amp breaker. For supply connection use 90degree C copper wire."


I attached a copy of the plate below. I also measured my distance last night and it appears to be around 150-160 feet. Since I don't want to deal with conduit, I assume 6 gauge NM is what I need. Does that seem right?



dwaun
 

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6 gauge on a 60A circuit is fine.

The reason I asked about your location is the label plate makes no sense. There are no suitable 8 gauge copper conductor types for use on a 60A circuit. But I believe there are circumstances under Canadian code which would allow it.

If you have time, and just for my own curiosity, could you check the generator to see which testing lab approved the Listing for this thing?
 
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