Master Bed/Bath Remodel w/ Subpanel?

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  #1  
Old 11-23-15, 07:36 PM
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Master Bed/Bath Remodel w/ Subpanel?

I'm remodeling my master bedroom/bathroom and got busted by local city building inspector for working without a plumbing and electrical permit. He didn't zing me with any fines and knows I'm already well into the job, but hasn't been in the house to know exactly how far. I'm currently waiting on permit approval and would like to keep plugging away at the job without covering any of the work before rough inspection.

My home is built on a crawl space, so the electrical panel is on the main floor with finished trim/drywall surrounding it. My home was built and plumbed for all natural gas appliances, but it was also built with a 30A 220V breaker with 10/3 w/ ground wire leading to and terminated inside a junction box in the crawl space. The junction box has "DRYER" written on it, so I assume this was intended to possibly be used for an electric dryer in the future.

My question is:

Rather than disturb all the drywall around my main panel. Can I label this 220v 30a breaker "MASTER BED/BATH" and feed a sub-panel in the master bedroom with 10/3 w/ ground rather than add five circuits to my main panel to feed my remodel? I'm looking at a total length of about 20-25 feet of 10/3 wire, including the existing jbox in the crawl. From the sub-panel in the bedroom, I'd like to feed the remodel with five circuits:
15a bedroom lights
20a bedroom outlets
15a bathroom lights
20a bathroom outlets
20a bathroom heated floor

Does this raise any flags for anyone with more NEC or home inspector familiarity?
 
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Old 11-23-15, 07:51 PM
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The panel cannot be in a clothes closet or in any part of the bathroom. IMO - your plan sounds fine.

I would not bother with two circuits for the bedroom and bathroom lights, they could likely be combined as the same circuit.

You likely do not need a 20 amp circuit for your floor heat unless it is quite large, the load of the heat mats/cable will determine the size of the circuit. A 15 amp circuit will likely suffice.
 
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Old 11-23-15, 08:06 PM
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Thanks, Tolyn.

The entry door to the bedroom will swing into the room and I was planning on installing the panel behind the door... so the door covers the panel when it's open.

In regard to combining the light circuits, point taken. The sub-panel I've purchased has 8 spaces and I don't think I'll ever use more than my five I previously mentioned, so I figured what the heck.

The bathroom is relatively large. Based on the mfr. specs for the cable length, the current requirement is 14.2 amps. I figured I should play it safe and feed it with 12ga/20a.

Thanks again!!!
 
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Old 11-24-15, 07:25 AM
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You will need to use AFCI breakers, especially since you're on the BIs radar. Their cost may "encourage" you to combine circuits where you can.
 
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Old 11-24-15, 07:40 AM
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Interesting... wasn't aware of these.

So are all new circuits required to be AFCI? It sound like they're required in new construction. If I added circuits to my existing panel, would they also need to be AFCI?

Also, is there such a thing as two-pole AFCI breaker? If so, can I swap out my existing 220V 30A breaker breaker that will feed the sub-panel with an AFCI breaker to provide AFCI protection on all sub-panel circuits?

Thanks for sharing!
 

Last edited by bajafx4; 11-24-15 at 08:01 AM.
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Old 11-24-15, 08:57 AM
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In my area, adding a new circuit, whether wired into existing panel or via a new or existing sub requires an AFCI breaker, if the current code requires an AFCI for that type/location of circuit.

Which locations/types of circuits that require AFCI depend on which version of NEC has been adopted in your area. The AFCI requirement has expanded pretty much with each version of the NEC, so the specifics are region-dependent. But bedroom outlets and, I think, lights, were one of the first areas they were required. Really only your AHJ can give you the final word.

They do make 2 pole AFCI breakers, but they are designed for shared neutral multiwire circuits, not to protect an entire subpanel. Also, I don't think anyone makes a "mini" AFCI, so make sure your sub has room for enough full size breakers.
 
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Old 11-24-15, 11:58 AM
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Thanks, Carbide Tipped.

After doing some research, it sounds like the sub will require all AFCI breakers with the exception of the bathroom outlets requiring a GFCI.

One thing I'm not sure of yet is if I can/should use an AFCI breaker for the bathroom outlets and install GFCI outlets on this circuit? Double protection or problem?

Also, the sub panel it a Square D QO w/ 8 spaces (16 circuits), so there's plenty of room there.
 
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Old 11-24-15, 12:29 PM
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It is a different kind of protection. AFCI monitors for the type of sparking from frayed cords or loose connections which can start a fire. GFCI monitors for current leakage to ground which can be due to a person with wet hands getting shocked. A couple manufacturers make breakers that offer both functions in one unit, otherwise you can use a standard GFCI receptacle on the AFCI breaker circuit.
 
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Old 11-24-15, 01:31 PM
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Thanks, Ben!

So with AFCI... let's say I'm vacuuming and I accidentally pull the cord/plug out of the outlet while the vacuum is running. Would this arc at the outlet trip an AFCI?
 
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Old 11-24-15, 01:45 PM
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It might although they are generally pretty good at ignoring single arc "switching actions". If you vacuum over a lamp cord and the beater brush breaks open the insulation causing multiple sparks, the AFCI should trip. Or a sofa that gets jammed against the wall and breaks a plug. Multiple sparks in a row that could cause a fire like a flint in a campfire.
 
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Old 11-24-15, 01:45 PM
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It shouldn't, but it might. The early versions were more prone to false tripping; they've gotten better. But its a pretty sophisticated task to discriminate between the situation you describe and what happens when you have a loose connection to the outlet, so they are not perfect. But most of the whining these days seems to be about the cost and expansion of where they are required to be used, and less about false tripping.
 
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Old 11-24-15, 06:06 PM
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Behind the door is an excellent place for your panel. I had a customer once who couldn't find their main service because it was behind the door.

I would recommend going with the Homeline of Square D. The AFCI breakers will be less expensive.

I do agree with the floor heat being on a 20 amp circuit if your load is 14.2, continuous load and all.

Some manufactures do make two pole AFCI's but I have not seen them in 30 amp.
 
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Old 11-24-15, 06:21 PM
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Originally Posted by Tolyn Ironhand
Behind the door is an excellent place for your panel. I had a customer once who couldn't find their main service because it was behind the door.
Haha... maybe that's not a good place for it. I can already hear my inspector saying that he can't find it.
 
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Old 11-24-15, 07:03 PM
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Found some more AFCI information regarding AFCI vs CAFCI (Combination AFCI).

[ATTACH=CONFIG]59288[/ATTACH]

The standard AFCI just protects from parallel arcs. Those would be arcs between line and neutral and line and ground.

The CAFCI protects the same as above plus it also protects from opens in a current carrying conductor which would be a series arc.
I assume I only need AFCI and not CAFCI at this date?

Also, maybe the CAFCI would be more prone to trip in my vacuum cord unplugging example???
 
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Old 11-25-15, 04:40 AM
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I assume I only need AFCI and not CAFCI at this date?
No. All AFCI's installed now are required to be combination AFCI's.

Also, maybe the CAFCI would be more prone to trip in my vacuum cord unplugging example???
No. CAFCI's are better at ignoring arcs that cause nuisance tripping.
 
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Old 11-25-15, 12:52 PM
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I am not sure the older AFCIs are even made anymore. All I have seen for several years are the newer combination AFCI breakers.
 
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