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#88063 05/07/04 08:07 PM
Joined: Oct 2001
Posts: 20
I would like to back up a second. Why do you have to run a #6 wire? It's a 50 amp circuit, why not run #8 THHN?

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#88064 05/07/04 09:20 PM
Joined: Oct 2001
Posts: 172
Take a look at 110.14(C)(1)(a) and then go to 310.16. The unit may not be listed and identified for 75C wire.

#88065 05/08/04 12:02 AM
Joined: Aug 2001
Posts: 545
aldav53 Offline OP
# 8 is good for 48 amps, and it is a fairly long run anyway.

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#88066 05/09/04 05:34 AM
Joined: Feb 2003
Posts: 198
Most of the Hot Tubs I have wired required # 6 cu conductors,as per manufacturer instructions.
How hot are the attics in your area? You will need to adjust your amps. Also you cannot sleeve NM outdoors, it is still a wet location,even above grade.

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#88067 05/09/04 09:47 PM
Joined: Apr 2002
Posts: 195
334.80: NM must be used at the 60* ampacity which is 40A for #8 and 55A for #6. If you run thhn in conduit then the ampacity will be 50A and 65A respectively if the terminations are marked 75*. I'm assuming that no other derating will be necessary.

#88068 05/09/04 10:02 PM
Joined: Jun 2003
Posts: 681
If you are running it in the attic (typical here in NY for the summer is about 120 degrees F), that would take a multiplier of .75 times 65 amp (for 6 AWG) which is now rated for 48.75 amps.


Pierre Belarge
#88069 05/10/04 12:21 AM
Joined: Aug 2001
Posts: 545
aldav53 Offline OP
The attics here in AZ do get hot, probably more than 120 deg. The spa calls for a 50 amp circuit. Derating the #6 might put it close. It would not make sense to do a splice just to run THHN through the pipe in that short run too the disc from the attic.

The Golden Rule - "The man with the gold makes the rule"
#88070 05/10/04 01:05 AM
Joined: May 2004
Posts: 4
Junior Member
I agree splices could create possible unwanted problems in the future.Best to not
splice the wire if possible.


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