10 guage 40 amp?

[saiprem]

Can I run 8 feet of 10 guage copper wire safely on a 40 amp breaker? Please email me at saiprem2@hotmail.com Thanks.

 

[roger]

Re: 10 guage 40 amp?

Saiprem, yes, but is it code compliant, it depends on what this is serving.

If you are only talking 8' why couldn't you just run #8? the cost difference would be pennies.

Roger

 

[dereckbc]

Re: 10 guage 40 amp?

I agree with Roger, use a #8 AWG. I doubt your terminal rating is 90 degree C.

 

[bphgravity]

Re: 10 guage 40 amp?

If this is a motor load, it may require the higher breaker for starting inrush. Still best to run the #8's though.

 

[saiprem]

Re: 10 guage 40 amp?

Thank you for your replies. I had to replace a burned out antiquated Federal Pacific 40 amp breaker, with a CH 40 amp breaker on another box 8 feet away. For the time being I ran 8 feet of 10 guage wire to connect it to the old 8 guage wire. I know it draws more than 30 amps, but I thought a very short length like that could handle it. Any more feedback?

 

[hurk27]

Re: 10 guage 40 amp?

If this wire is being used to feed a resistance load like a heating elements. it would be wise to monitor the wire to see if there is any heating and change it A.S.A.P.
If this is a continuous load then I would install the right wire.

 

[mkbuck]

Re: 10 guage 40 amp?

Read 240.4(D)

The overcurrent protection shall not exceed 30 amperes for a 10 AWG conductor, unless covered by the conditions described in 240.4(E),(F) or (G).

This does not seem to be the case here.

I would install an 8 AWG A.S.A.P.

 

[iwire]

Re: 10 guage 40 amp?

It worries me that a wire that apparently needed replacement due to overheating was replaced with a smaller wire, I would get a #8 in as soon as possible.

Originally posted by mkbuck:
Read 240.4(D)

The overcurrent protection shall not exceed 30 amperes for a 10 AWG conductor, unless covered by the conditions described in 240.4(E),(F) or (G).

Do not forget as BPH pointed out motor loads may have much larger breakers then the rating of the conductors feeding them.

For motor loads it is possible to have #12 on a 60 amp breaker and still be code compliant.

Refer to 430.52 and the rest of Part IV of 430, also parts of 440

 

[saiprem]

Re: 10 guage 40 amp?

Thank you. I am now connecting the 40 amp breaker to the 8 guage wire with two 10 guage wires. That oughta do it.

 

[don_resqcapt19]

Re: 10 guage 40 amp?

You are not permitted to parallel #10 wires, the smallest that you can parallel pre 310.4 is 1/0.
Don

 

[luke warmwater]

Re: 10 guage 40 amp?

You can't do that, besides, if you could run another #10, why not run the required #8??

 

[saiprem]

Re: 10 guage 40 amp?

Thank you all. I've just been lazy. I will fix it asap.

 

[electricmanscott]

Re: 10 guage 40 amp?

 

[saiprem]

Re: 10 guage 40 amp?

I'm glad I found this forum!