continuous load

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The electron man

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Electrician
If I have a 37amp continuous load conductor
sized to * 1.25 = 46.25

so I would use #6 rated at 55amps

But what about my ocpd

Would I take my load of 37 * 1.25 = 46.25

There in no breaker rated at 46.25 so I would use a 50amp breaker correct ?
 
What is the wiring method (conduit and wire, MC cable, NM cable, Etc.)? In the list I mentioned all but NM cable can be used as a 75° C conductor meaning that #8 AWG is sufficient for 50 amps.
 
infinity said:
What is the wiring method (conduit and wire, MC cable, NM cable, Etc.)? In the list I mentioned all but NM cable can be used as a 75° C conductor meaning that #8 AWG is sufficient for 50 amps.
Click to expand...
Don't we use the 60° column for anything under 100amps and its conduit and wire
 
The electron man said:
If I have a 37amp continuous load conductor
sized to * 1.25 = 46.25

so I would use #6 rated at 55amps

But what about my ocpd

Would I take my load of 37 * 1.25 = 46.25

There in no breaker rated at 46.25 so I would use a 50amp breaker correct ?
Click to expand...
Yes! For Nonmetallic Sheathed Cable with a 60 degree C rating!
 
The electron man said:
Don't we use the 60° column for anything under 100amps and its conduit and wire
Click to expand...
The electron man said:
Its thhn so what column would I use and was the calculation for my ocpd correct ?
Click to expand...
THHN is 90° C conductor and can be used at its 75° C ampacity when the wiring method is conduit and wire. NM cable is limited to the 60° C ampacity due to 334.80.
 
The electron man said:
Don't we use the 60° column for anything under 100amps and its conduit and wire
Click to expand...
Yes as a default if terminal ratings are unlabeled. But in practice most equipment terminals are rated for 75C wire. So if you are using a 75C wiring method (not NM, not LFNC or LFMC in a wet location), and you confirm that the terminals are labeled for 75C wire, you get to the use the 75C column, even under 100A.

And yes, you need a 50A breaker with conductor ampacity of at least 46A.

Cheers, Wayne
 
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