OK, so I am wiring my cabin (actually a small house, 16x24), and I have a 6x8 room that will eventually become a bathroom, and a nook that will be a kitchenette. All the wiring in the house is surface mounted EMT conduit & metal boxes (long and goofy story about why this is so and not romex in the walls)

In the bathroom, is there that much of a safety advantage to running PVC conduit? Or is EMT and metal boxes okay? Of course all outlets/switches/boxes are to be grounded. My worry is the steamy shower air settling and condensing to drops on the parts inside the boxes.

Also, after some research, I have interpreted that:

  • In a single bathroom, outlets/lights/and fan may be on the same breaker and it must be GFCI protected.
  • In kitchens, the convenience receptacles must be on their own 20A GFCI-protected breaker with 20A outlets, separate from lighting. (not including fridge/oven etc which must be separate)
  • In kitchens the lighting circuit does not have to be GFCI or CAFI protected.

So (assuming I'm correct in my research above) my plan is:

  • One CAFI/GFCI 20A circuit to the bathroom with two 20A outlets, a vent fan, and a surface-mount LED light fixture.
  • One CAFI/GFCI 20A curcuit to the kitchen convenience outlets, in EMT conduit with 20A outlets in metal boxes
  • One CAFI 15A circuit to the kitchen light fixture (same fixture as bathroom). I know CAFI isn't necessary (right?) but I assume it can't hurt to have the extra safety margin.
  • One CAFI/GFCI circuit to power the fridge.
  • 2
    The point of codes separating the GFCI and general lighting circuits in the bathroom and kitchen is so that when the blender/hair dryer trips the GFCI the lights don't also go out on you. There is an exception in the code for a single bathroom. This is mostly to enable retrofits. In a small cabin with new wiring I would think you can probably engineer the kitchen lighting circuit to also service the bathroom. This is not required but will give you a better setup overall. Keep in mind that newer codes require a neutral at the switch box even if you are running a switch loop.
    – Stanwood
    Mar 27, 2018 at 22:35
  • AFCIs might be required in the kitchen depending on which version of the NEC is in effect where you are. As for, "It can't hurt," that depends on whether nuisance trips constitute "hurt" or not. I personally have zero experience with AFCIs, so that part is completely anecdotal
    – Hari
    Mar 27, 2018 at 23:03
  • 2
    2 ea 20 amp counter top branch circuits are required for a kitchen even if you only have 2 outlets 2 circuits are required.
    – Ed Beal
    Mar 28, 2018 at 0:13

3 Answers 3

  • if a circuit powers receptacles in 2 bathrooms, the only other things that can be on it are receptacles in any number of bathrooms.
  • if a circuit powers receptacles in only 1 bathroom, the only other things that can be on it are other (hardwired) loads in that same bathroom.

The reverse is not true; a hardwired load in a bathroom can be powered off any convenient circuit (unless its rules prohibit that). That is a good idea so you don't plunge the bathroom into darkness when you trip a GFCI/breaker. Those hardwired loads do not need GFCI protection.

One thing I would do in bathrooms is run a ground wire in the conduit. That gives you "belt and suspenders" grounding in the off chance of an EMT rust-out or physical damage. Just because good grounds are so helpful there.

There need to be two 20A circuits that serve kitchen countertop/convenience receptacles, as described in RME's answer.

There is nothing wrong with more. Any kitchen appliance which uses heat aims to use 1500W - that means a 20A circuit will trip with two of them, and the savvy chef must learn his kitchen's circuits and put his appliances in possibly awkward positions. Therefore, it is not excessive to have a breaker per socket - done by feeding it from two 1-pole GFCI breakers handle-tied, or a 2-pole GFCI (as MWBC). The handle-ties are required due to common-yoke rules.

This kind of thing is why we say "get panels with lots of spaces".

It's not illegal to put the fridge on one of the two kitchen general countertop circuits. However...

I generally do everything I possibly can to assure that the refrigerator is on a dedicated circuit.

GFCI and AFCI protection has specific reasons for existing; these reasons being the use case. An all-steel refrigerator with all its mechanical equipment shielded, on a dedicated homerun 1-socket circuit, is not a reasonable use-case for GFCI or AFCI. They provide a negligible safety margin, and introduce a different safety problem: spoiled food. As such I recommend using every trick possible to avoid a fridge being on a GFCI or AFCI.

Being a dedicated circuit averts the nightmare scenario: the GFCI trips, fridge warms up, is reset because other loads are interrupted, the resetter is oblivious that the fridge is also on that circuit, fridge re-chills, and food is used as if it's good.

A dedicated circuit reduces the worst-case scenario to a GFCI nuisance trip causing a warm fridge and a bunch of spoiled food.

AFCIs are designed to catch two types of defects: first, electric blankets - did I say electric blankets? I meant arc-faulting wiring inside any appliance... and second, faulty wiring in walls (i.e. backstabs). EMT conduit and steel boxes greatly ease the latter. EMT doesn't stop it from arcing, but it's a good thermal conductor and will spread heat away from the arcing point before it can reach combustion temps. When insulation melts enough to let a melting "hot" touch the conduit, it will cause a bolted fault and trip the breaker. This is no help if it's a melting neutral.

All that to say, in EMT, AFCI is not my highest concern, unless I have a reason to doubt the appliances.

  • OK, so new plan: -- two 20A GFCI/CAFI circuits to kitchen countertop outlets. Total of five, one circuit to 3 outlets, another to the other 2 outlets -- one 20A CAFI/GFCI to the bathroom outlets -- one dedicated 15A CAFI to both the kitchen and bath lights/fans -- one dedicated 20 plain-jane (no GFCI or CAFI) breaker to a single outlet marked for refridgerator (which is at least 6ft away from sink). How's that sound? Mar 28, 2018 at 14:43
  • Oh yeah ... and regular EMT/metal boxes in the bathroom with ground wires installed at each outlet Mar 28, 2018 at 14:51
  • 1
    Sounds good... check with your AHJ on the refrigerator outlet, when I say "avoid GFCI/AFCI at all costs" I mean there is sometimes friction with the AHJ about that. Mar 28, 2018 at 14:53

EMT is okay for wet areas, in fact it's widely used in outdoor settings. If you're concerned about moisture, you could use compression fittings and metal boxes intended for wet settings. However, they'll likely be more expensive and may not be needed (others may confirm/deny).


It's not a bad plan except NEC requires at least 2 - 20A circuits in the kitchen for small appliances. These circuits can also be used in the dining area, pantry and breakfast nook. That's Article 210.52 (B)(3).

Good luck.

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