This is my first DIY electrical project, so I am looking for some advise about the proper way to run the following 3 new circuits that I'll need for a basement kitchen that I am building: enter image description here

I am currently reading the "Canadian Electrical Code, Part 1" in preparation for this DIY electrical work, but it creates a lot of questions that I am hoping someone with experience can help me with.

Most of my ceilings in the basement is drop-ceiling, covering exposed joists above. All the existing wiring is stapled to the bottom face of the joists, which according to CEC is not allowed anymore, so I cannot do it that way, correct? I am basing this on Rule 12-514-b:

Cables shall not be run on or across the lower faces of basement 
joists, unless suitably protected from mechanical damage.

So I guess that means that my only option is to drill holes through all the joist and run the cables that way. This creates 2 questions:

Q1) What do I do when joists have HVAC ducts taking up the space between the joists that I need to cross? I know that cables require a minimum separation of 25mm from heating ducts, so what are my options? What kind of "mechanical protection" do I need to use, if I do need to staple to the bottom of the joist?

Q2) I have one 3-wire circuit and two 2-wire circuits to run. Can they all be run in the same hole? I can't find any info in the code about how many NMD90 wires are allowed in one joist hole...

Next, there's the question of how to run the wire over the part of the ceiling that is not accessible to me. There's a dry-walled, dropped section of the ceiling running along the entire length of the basement, and that I need to cross before I can get from the panel to the side of the house where the drop-ceiling is. What are my options for crossing that space, considering that I cannot support the cable every 1.5m as per Rule 12-510-1-a, without completely opening up the ceiling?

I found this rule about fishing wire:

== 12-520 Fished cable installation ==

Where the cable is used in concealed wiring and it is impracticable to 
provide the supports required by Rule 12-510, and where metal sheeting 
or cladding, metal joists, metal top or bottom plates, or metal studs 
are not used, the cable shall be permitted to be fished.

So my last question is:

Q3) Did I understand correctly that I can simply fish the wire over the obstruction w/o any sort of conduit? What if that space contains metal HVAC ducts? Do I need to use some sort of conduit then? Is NMD90 wire even allowed to be run through conduits? What are my options?

Any advice would be greatly appreciated!

  • 1
    BTW: is there a reason you have an AFCI outlet past the GFCI outlet, instead of using an AFCI breaker? – ThreePhaseEel Nov 3 '18 at 4:19
  • 2
    Yeah, that caught my eye too, it is fairly pointless. The real purpose of AFCI is to protect in-wall wiring, and it won't be doing any of that if it's all the way at the end of the wire run! A lot of people go "AFCI rhymes with GFCI therefore it must install the same way", nuh-uh. – Harper - Reinstate Monica Nov 3 '18 at 7:44
  • @ThreePhaseEel My thought there was to comply with Rule 26-656-1-a-ii/26-724-d-iii. It says that receptacles along the wall at counter work surfaces SHOULD NOT be protected by AFCI. But since I couldn't find any exemption for the opposite wall plug, I thought I had to provide separate AFCI protection there. Did I read that wrong? – Val Blant Nov 3 '18 at 20:07
  • @ThreePhaseEel btw, my intention for that AFCI outlet was for it to be GFCI protected as well, which I thought I achieved by connecting it to the GFCI outlet upstream, which is also the first on the circuit. Is that right? – Val Blant Nov 3 '18 at 20:09
  • @ValBlant -- but the GFCI outlet isn't AFCI protected in your current setup – ThreePhaseEel Nov 3 '18 at 21:39

Another option is run EMT conduit across the bottom of joists. EMT can be used in one of two modes:

  • as a simple protective shield for the Romex style cables. In this case, contemplate larger conduit diameters such as 3/4" for a single cable or 1-1/4" to 1-1/2" for multiple cables. The "conduit fill rules" require fairly large pipe when flat Romex is involved, because it can't be counted on to lay flat. In this case you do not need steel boxes at the end of the conduit run, but the end of the run needs to be protected.

  • as the Conduit Wiring Method, requiring steel junction boxes at both ends. In this case you can pull cables through large conduit as above, but instead, may make a splice inside the junction boxes to wires more appropriate to the Conduit wiring method.

The EMT Conduit Wiring Method is a great way to wire, when you are able to do it. You don't need a ground wire (the EMT is the ground) and you can run individual THHN type wires, which also can be stranded wire, for much better handling and flexibility. It allows you to carry as many as 4 circuits inside a 1/2" pipe.

In any case, if several circuits are running together in a conduit pipe or simply bundled together for 600cm or farther, assure there are no more than 3 circuits together. However 4 circuits is allowed if all of them are #12 (20A) or smaller.

If you ever envision having 3 or more circuits, make the steel boxes at the end of the conduit run be 4-11/16 (120mm) boxes that are 55mm deep. That provides enohgh space for up to 4 circuits worth of splices.

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  • That sounds like a good idea. So what do I do if I can't support the EMT conduit every 1.5 meters, as required by Rule 12-1010? That closed off ceiling area in my basement is wider than 1.5 meters. I can easily fish the conduit through and support it on both sides of the obstruction, but the supports would be more than 1.5 meters apart. The rules say that with #41 conduit (1.9" OD), the supports can be 3 meters apart, which is long enough. Does it make sense to use the really thick conduit just to clear the obstruction, and then use smaller conduit everywhere else? – Val Blant Nov 5 '18 at 21:37
  • Mechanically protection could be as simple as stapling the wires on the side of wood that is nailed to the underside of the joists. The wires are protected because the wood gets hit first before the wires. Or run armoured cable(bx) for the main runs across the joists. – user68386 Nov 6 '18 at 18:51

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