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View Full Version : 6ga Wire for 60A Sub-Panel?



Bob Sisson
12-19-2012, 03:43 PM
Ok... in the Main panel there was a "Pool Circuit" that feed (via 4-wire) the Pool sub-panel.

The Wires were 6ga Cu Black THHN/THWN type wires and were re-marked with White & green tape to identify the Neutral, Gnd and the Two Black Hots and were in a Grey PVC conduit.

The question is: Is a 60A Breaker appropriate?

iN MY BOOK, 6ga is listed as 55A for Branch Circuits, and not listed for Service Conductors. I show #4 for 60A Service conductors...

I flagged it, but wanted to check anyway...

Is there something special about THHN/THWN type wires or seperate wires in a conduit that would allow this, or is it just wrong like I think it is.

PS...according to another forum you can "re-identify" anything smaller than #4 and it should have been in METAL coduit, not plastic and...and...
So I think that this is just WRONG on several layers...

Bob Sisson
12-19-2012, 04:47 PM
I wasn't sure...the cheat sheet in my Report binder says 55A...

Thats why I was checking...

Jim Port
12-19-2012, 04:50 PM
The wires need to be larger than #6, not smaller. The smaller sizes are easily available in the correct colors.

Mike Kleisch
12-20-2012, 12:19 AM
Check Art 240 based on the 2008 NEC

You have that goofy situation in the code where you can round up to the next "standard ampere rating" NEC 240.6(A) . The NEC lists 50 amp and 60 amp but not 55 amp, so NEC 240.4(B) allows you to use the next standard ampere rating which is 60 amp, if you comply with the 3 other requirements in section 240.4(B).

We have not adopted the 2011 NEC, so I'm not sure if it the same, but guess it is.

ken horak
12-20-2012, 06:45 PM
# 6 THHN / THWN Copper is rated for 65 amps in the 75 degree column. Seeing how you have #6 THHN / THWN conductors the 60 ampere overcurrent device is correct.

PVC conduit is allowed to be used for the feeder to the pool subpanel.

See: NEC article 680.25(A)(1)