Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker?

08-11-2012, 10:51 PM	#1
crankcase Member     Join Date: Sep 2010 Location: Minnesota Posts: 127	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? If I'm reading my instruction sheet correctly my QO 15A CAIF it will trip instantly for a shared neutral. Does that mean that I am not allowed to use it to feed 1/2 of a MWBC?

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08-11-2012, 11:00 PM	#2
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,220	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? That is correct...and one of the huge downfalls of AFCI's. Although some manufacturers are starting to produce 2 Pole AFCI breakers. I think Siemans is one and I forget the other one. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

08-11-2012, 11:18 PM	#3
crankcase Member     Join Date: Sep 2010 Location: Minnesota Posts: 127	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Thanks, I didn't realize it right away. Going to have to run those 2 a little different then.

08-12-2012, 06:10 AM	#4
kbsparky Electrical Contractor     Join Date: Sep 2008 Location: Delmarva Posts: 3,125	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Quote: Originally Posted by k_buz ... I think Siemans is one and I forget the other one. Cutler-Hammer comes to mind .... __________________ -KB Life is uncertain -- eat dessert first!! To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

08-12-2012, 11:13 AM	#5
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,069	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Square D makes 2pole AFCI's.... QO style too. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

08-12-2012, 11:15 AM	#6
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,220	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Link? A quick Google search did not provide any matches. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

08-12-2012, 11:19 AM	#7
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,069	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Quote: Originally Posted by k_buz Link? A quick Google search did not provide any matches. I cant find a link either, but Im almost positive we just did a job with a panel full of them. I will verify this on monday... Sq D's website is pretty bogged up.... __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. Last edited by stickboy1375; 08-12-2012 at 11:31 AM.

08-12-2012, 12:08 PM	#8
Jim Port Licensed electrician   Join Date: Sep 2007 Location: Maryland Posts: 5,942	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? I thought Cutler was one of the few making a 2 pole AFCI. __________________ Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.

08-12-2012, 12:11 PM	#9
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,220	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Quote: Originally Posted by Jim Port I thought Cutler was one of the few making a 2 pole AFCI. I have found CH and Siemans. This is the interesting thing, the code has been around for a long time now and only two types have been produced and nobody has came out with a listed AFCI receptacle. Why? Seems like the code is ahead of the technology. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

08-12-2012, 12:27 PM	#10
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,069	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Quote: Originally Posted by k_buz I have found CH and Siemans. This is the interesting thing, the code has been around for a long time now and only two types have been produced and nobody has came out with a listed AFCI receptacle. Why? Seems like the code is ahead of the technology. AFCI receptacles would be a sweet deal, and fix the multiwire branch circuit issues... Of course, I just rough in with 14-2-2 or 12-2-2.. so it's a non issue for me. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

08-12-2012, 12:32 PM	#11
k_buz Licensed Electrician     Join Date: Mar 2012 Location: SE Wisconsin Posts: 3,220	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? The problem with AFCI receptacles is you have to meet a number of criteria to install them. From 2011 Quote: Exception No. 1: If RMC, IMC, EMT, Type MC, or steel armored Type AC cables meeting the requirements of 250.118 and metal outlet and junction boxes are installed for the portion of the branch circuit between the branchcircuit overcurrent device and the first outlet, it shall be permitted to install an outlet branch-circuit type AFCI at the first outlet to provide protection for the remaining portion of the branch circuit. __________________ Location...Location...Location Answers based on the National Electric Code. Always check local amendments.

08-12-2012, 12:34 PM	#12
stickboy1375 E2 Electrician     Join Date: Apr 2012 Location: Litchfield, CT Posts: 3,069	Can I feed 1/2 a MWBC from a combination arc fault interrupter(CAIF) breaker? Quote: Originally Posted by k_buz The problem with AFCI receptacles is you have to meet a number of criteria to install them. From 2011 Im betting there is no market place for the device, meaning, too expensive to produce for such little demand. I could be off on this of course. Not sure as a manufacture I would invest in this product though. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.