50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center?

06-03-2012, 10:40 AM	#16
LooseSCruz Member   Join Date: Feb 2012 Location: Central Coast, Cali Posts: 105	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by mgambino I just (quickly) looked over art 525 and the only thing that might be an issue is how you connect to power and the amps city of #8 SOW. You may be required to connect to power via a receptacle instead of hard wiring to a breaker. 8/3 SOW is only rated for 35a. Since 35a is considered a common breaker size, you couldn't fuse it at 40a. Its a 50amp 220 box at fairground to 8/3 grounded to my trailer where is goes to 40 amp main then individual breakers. 8/3 is rated for 40 amp. I have provided my draw which totals @35 amps. Maybe I am not understanding what you said? He's saying your cable isn't rated for 40A but rather 35A. See NEC Table 400.5(A)

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06-03-2012, 10:42 AM	#17
LooseSCruz Member   Join Date: Feb 2012 Location: Central Coast, Cali Posts: 105	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by mgambino The 400.5 A state 40 amps with 2 conductors. GFI is not the issue at hand. Next? You have 3 current carrying conductors. Two hots and the neutral. The 35A limit applies.

06-03-2012, 10:43 AM	#18
Jim Port Licensed electrician   Join Date: Sep 2007 Location: Maryland Posts: 5,961	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? 8-3 flex cord would only have one hot, one neutral and a grounding conductor. How do you plan to feed the second leg of the panel? 8-4 would have two hots, a neutral and a grounding conductor. __________________ Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.

06-03-2012, 10:46 AM	#19
mgambino Newbie   Join Date: Jun 2012 Posts: 19	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: You have 3 current carrying conductors. Two hots and the neutral. The 35A limit applies. Ok but when breaker one is on breaker 2 is off. When breaker 2 is on breaker 1 is off. Reducing my load to less than 35.

06-03-2012, 10:47 AM	#20
mgambino Newbie   Join Date: Jun 2012 Posts: 19	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: 8-3 flex cord would only have one hot, one neutral and a grounding conductor. How do you plan to feed the second leg of the panel? 8-4 would have two hots, a neutral and a grounding conductor. Its a 8/3 WITH GROUND.

06-03-2012, 10:51 AM	#21
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,071	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by LooseSCruz You have 3 current carrying conductors. Two hots and the neutral. The 35A limit applies. The neutral is only carrying the unbalanced current, so technically he only has two current carrying conductors. If i'm reading that correctly anyhow.

06-03-2012, 10:52 AM	#22
mgambino Newbie   Join Date: Jun 2012 Posts: 19	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by stickboy1375 The neutral is only carrying the unbalanced load, so technically he only has two current carrying conductors. If i'm reading that correctly anyhow. YES! 2 hot 120s 1 neutral and one ground.

06-03-2012, 10:52 AM	#23
LooseSCruz Member   Join Date: Feb 2012 Location: Central Coast, Cali Posts: 105	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by mgambino Its a 8/3 WITH GROUND. Stop yelling. It's not Jim's fault you didn't know that the appropriate term was 8/4. As for your reply to my post, the issue here is not whatever your actual load may be. The issue is that you can't protect 8/4 SO with a 40A breaker, you need a 35A.

06-03-2012, 10:56 AM	#24
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,222	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Neutrals count as current carrying conductors. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

06-03-2012, 10:56 AM	#25
LooseSCruz Member   Join Date: Feb 2012 Location: Central Coast, Cali Posts: 105	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by stickboy1375 The neutral is only carrying the unbalanced current, so technically he only has two current carrying conductors. If i'm reading that correctly anyhow. I've always been under the impression that the neutral is factored in as current carrying. If that's not the case, I'm happy to be corrected but that's just how I've always seen it done.

06-03-2012, 10:57 AM	#26
mgambino Newbie   Join Date: Jun 2012 Posts: 19	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by LooseSCruz Stop yelling. It's not Jim's fault you didn't know that the appropriate term was 8/4. As for your reply to my post, the issue here is not whatever your actual load may be. The issue is that you can't protect 8/4 SO with a 40A breaker, you need a 35A. YES! Was an expression of happiness that someone read my original post that stated 8/3 with ground. The invoice from the electrical supply says 8/3 with ground. I was thinking 8 gauge 3 shielded with one unshielded ground.

06-03-2012, 10:58 AM	#27
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,071	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by k_buz Neutrals count as current carrying conductors. If you read 400.5 (B) A neutral conductor that carries only the unbalanced current from other conductors of the same circuit shall not be required to meet the requirement of a current-carrying conductor.

06-03-2012, 11:03 AM	#28
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,071	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by LooseSCruz I've always been under the impression that the neutral is factored in as current carrying. If that's not the case, I'm happy to be corrected but that's just how I've always seen it done. It depends, check out 310.15(B)(4) as to when a neutral IS to be counted as a current carrying conductor....

06-03-2012, 11:07 AM	#29
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,222	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? You make a valid argument. However, I have never been able to exclude neutrals from the count and I'm not quote sure why this would be the case. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

06-03-2012, 11:10 AM	#30
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,071	50 amp 220 over 8/3 with ground to 40 amp double breaker feeding into load center? Quote: Originally Posted by k_buz You make a valid argument. However, I have never been able to exclude neutrals from the count and I'm not quote sure why this would be the case. Because code says so. The neutral ALWAYS carries current, were just allowed to ignore it in some situations.... that's the best answer I can give you. Check out section 310.15(B)(4), This applies to more than just flexible cords and cables.