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I'm looking for input on the safety and code compliance of the wiring plan i've detailed, shown in the photos below.


Description of the broader project

My jurisdiction is subject to the 2014 NEC. I'm planning to install downlights throughout my house, on one circuit, power at light, with groups of lights on separate switches (led fixture housings rated for max 25 watt bulbs, and airtight-ic Halo Model #H750ICAT). There will be nearly 50 of these fixtures on this one circuit (intending to install with 20 amp dual CAFCI+GFCI breaker (Square D Model #QO120DFC, using 12ga nm-b cable).

Description of this portion of the project detailed in the photos below

This particular portion of the project is for a bathroom; one of the light housings will be installed above the shower (thus the AFCI+GFCI protected circuit for interior lighting, to provide both AFCI and GFCI protection).

Photos of Electrical Diagrams

The first pic shows the switches in the room I'm focusing on with this first stage. Please ignore the fan/heater/light/night-light unit; I'm specifically looking to get input on the safety and code compliance of the downlight wiring.

1 - switch plan src

The second pic shows the general principle I think will allow me to carry power across the light fixtures, while switching groups separately.

2 - wiring diagram in principle src

The third pic details the principle in the second pic in greater detail

3 - wiring principle -- detailed diagram src

Thank you!!


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    As far as the load on the circuit you will be fine if the fixture is rated for the 25w as a max. if the fixtures are standard 60w cans then no, that will be beyond the allowed load because you could put 60w in each can and draw 3000w. The fixture for the shower will need to be listed for a damp/wet location in a shower but that is allowed. I can’t see the schematics well on my phone but if the total load is only 80% of the 20 amp load it will be ok as lighting is considered a continuous load so you use 125% of the load values and keep them below 20 amps 20x120v=2400w 2400w x .8= 1920w max – Ed Beal Jan 21 at 20:04
  • It's common to use 15A circuit breaker and 14AWG cable for light fixtures. 14AWG is easier to pull / install, more of it fits in boxes (box fill limits), and saves you money. – Jeff Wheeler Jan 21 at 21:03
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    @Harper-ReinstateMonica OP said "12ga nm-b cable". See the highlighted items in picture 3. – manassehkatz-Moving 2 Codidact Jan 21 at 21:16
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    I took a swing at brightening up the pix. – Harper - Reinstate Monica Jan 21 at 23:24
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    @manassehkatz-Moving 2 Codidact -- you might have seen it earlier, but I edited my post after seeing your comment because you reminded me I hadn't included the correct details for the breaker I was planning to use (a DF C/AFGFCI, pricey little thing)... thanks for jogging my brain! – The Ghost of Jon Jan 22 at 1:43
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This looks good, although you'll have to pay attention to keeping your neutrals separated in the switch boxes!

Your plan for the light circuit should not be an issue at all; you're running proper NEC 2011 new-style switch loops with neutrals provisioned for future use, and your fixtures are designed to take LED modules, not Edison-base bulbs, so some dim bulb incandescenthead can't go in and overload the circuit with their heat globes, either.

The one caveat, though, is that you can't just glom all the neutrals together in the switch boxes like you're used to. You'll need to keep the lighting neutral strictly separate from any other neutrals present there to avoid falsely tripping your GFCIs, if nothing else.

Also, in an unrelated note, I'd consolidate the two apparently-adjacent switch boxes in your plan into a single six-gang box. If that's impossible, though, I'd at the very least get all the fan switches into one box and move the switches for the rest of the lighting out by themselves so that you don't have awkward problems with crossed wires. Another aid to dealing with that is using individual THHN wires in ENT ("smurf tube") between the fan and its light switch box; that way, you're no longer constrained by cable configuration limitations.

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  • Thanks @ThreePhaseEel !! Great points, I like the smurf tube with individual conductors and appreciate the note on the neutrals, though I try to avoid it so I don't inadvertantly overcurrent – The Ghost of Jon Jan 22 at 2:54
  • @Jon now that you've taken the tour, you'll know to click the up arrow (if you haven't already) to say "thanks" for any answer that you find useful and helpful, and (give it 24- to 48-hours to see if anyone else is interested in chiming in), click the check mark on the answer that helps you the most. – FreeMan Jan 22 at 14:54

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