I was set to replace a 60 amp breaker, until I opened the panel and noticed that the wire going out of it was only an 8 gauge wire. I would have expected to see at least a 6 gauge wire. I was thinking of putting in a 40amp breaker instead. This breaker runs to another suppanel, which has a clothes dryer and seven 60-watt lights running off of it.
Should I install a 40 amp or is replacing with a 60 amp with AWG 8 gauge OK?
Tark
Replies
#8 - 90ยบ C wire is rated for 55 Amps with no more the three current carrying conductors in a raceway....how far is the sub from the main panel?
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, wer ist jetzt der Idiot ?
Maddog3-- Don't overlook NEC 2005 Article 110.14[c](1)(a)."Terminations provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors. shall be used only for one of the following:
(1) Conductors rated 60*C (140* F)
(2) Conductors with higher temperatures ratings, provided the ampacity of such conductors is determined based on the 60*C (140*F) ampacity of the conductor used.
(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.I believe that the ampacity of the wire must be determined by the temperature listing of the breaker. Most are listed for 60* if I recall correctly, thus limiting the #8 to 40 amps.
Chuck
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Thanks Chuck, I try not to overlook that section especially with transformers.....#6 would be appropriate,.
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., wer ist jetzt der Idiot ?
Thanks to everyone that responded.The sub panel is about 20 feet away. There are four circuit breakers, 30amp for the dryer, and 2 - 20amp (exterior recepticle and garage), and 1 - 15amp for the exterior lights.The building is identical to other buildings on the block (multi-residential units all built by the same developer) From what I've checked, this particulat circuit has a 60amp breaker in the other building. That said, it sounds like 40amp breaker is the safer way to go.Thanks again!
What breakers are at the subpanel?
I suspect the dryer breaker is 40amp or less. The breaker for the lights doesn't really matter.
If the dryer does have a 40amp or smaller breaker, I would not worry about it.
#8 wire will carry 40 amps unless it is through the air.
Normally a dryer uses a 30 amp breaker and #10 wire.
Edited 2/14/2007 7:35 pm by gb93433