By far, this is the most dangerous DIY project I have ever attempted, it’s done, I am still alive. Installing Sub Panel is something you should hire a licensed electrician to do it, but it is so easy and I strongly recommend and encourage serious DIY people to do it. Well, can it pass inspection and is it 100% up to code? I cannot guarantee. But is it safe? Well, I studied a bit of NEC and CEC on selected topics before doing this. Let me know if you find any mistakes and I will try to correct it.

What do you need to know?

In Canada, our receptacles are 110-120V. But stove, air conditioner, cloth dryer are 220V, before you start the project make sure you understand all the following. Information on the Internet can be confusing because many articles are in U.S. (NEC) which has different standard than in Canada (CEC).

  • Pay attention to Sub Panel’s neutral and ground bonding, according to NEC 250.24(A)(5), they have to be not connected on the sub panel. Google it for more information.
  • Single pole, Double pole, Tandem circuit breakers
  • Load calculation
  • Hot(s), Neutral, Ground in 120V/240V
  • Wire size gauge (14, 12, 10, 8, 6 awg)
  • Circuit breaker amp (15, 20, 30, 50, 60, amp)
  • Wire NMD90 vs NMWU (90c vs 60c temperature rating)
  • Brand of main panel and sub panel (Cutler Hammer Eaton, Siemens, etc)
  • NMD90 (Canada) vs NM-B (USA)
  • NEC vs CEC

Sub Panel vs Tandem circuit breakers and cable selection

In our house, the main panel ran out of space from day one after we installed AC, recessed lights, dedicated breaker for my servers. I could have used Tandem circuit breakers to free up some space, but I do not like the idea honestly speaking. So, I bought a 100 Amp Siemens EQL8100D Sub Panel from Home Depot with 1.5 meters Romex NMD90 6/3. After load calculation, the maximum I would put on the sub panel is 60 Amp in total.

Why 6/3? As per Southwire Canada and US official specification, here are the important information on wire gauge selection. You have to study VERY carefully, selecting the wrong cable can cause fire. In this case, NMD90 6/3 is my selection.

In Canada:

  • NMD90 6/3 – 65 Amp
  • NMD90 3/3 – 105 Amp
  • There seem to have no Romex NMD90 4/3 or 2/3 in Canada

In U.S:

  • NM-B 6/3 – 55 Amp
  • NM-B 4/3 – 70 Amp
  • NM-B 2/3 – 95 Amp

Installation Process

The installation process was easy, took me around 2 hours totally. My UPS for my servers were up and running during the whole time when I turned off the main breaker. I had to re-wire a 20Amp (12 awg garage receptacle) and a 15Amp (14 awg recessed lights) to the sub panel, the rest is pretty much self explanatory in the photos.

Tesla or Hot tub?

Originally my wife wanted to buy a hot Tub as part of the backyard project, we even bought the hot tub GFCI disconnect spa panel. But we changed our plan and returned the GFCI spa panel. Now, the next plan is to use this 240V 50A double pole breaker for Telsa Model 3 as it becomes more affordable.

Do I need permit and inspection?

Before I answer this, let me tell you a story. When we hired the guys who installed the pot lights (recessed lights) several years ago, the person is a licensed electrician. At the end of the installation he gave me a ESA form and I needed to pay extra $200 for inspection, but he offered an option to opt out and deducted $200. So I took the offer, all cash transaction for around 30 lights at $2300 cash deal. No tax and no receipt it’s a win-win situation. Did he pull any permit? No. Did we get inspected? No. I inspected his team’s craftsmanship and it was great, of course we just trusted his work on electrical code. They were rated 10/10 on back then. If a licensed electrician did that, my simple answer for my project is – No.

Disclaimer for DIY: This article is for reference only, hire a licensed electrician if you are not comfortable. You can get killed if you do not know what you are doing, I mean you deserve to die if you connect ground as hot, or you deserve to get your house burned if you wire a 60 amp breaker with a 12 awg. I hold no responsibility for the use of this information. If you have heard about “Isaac Lawrence Improper Electrical Wiring” case (Google it), you better be very careful when you hire the professionals, do proper screening and read the online reviews. Make sure you get top quality professional in the industry locally. Good Luck.


  1. Thanks for posting this!! I was looking at the same panel (garage sub panel for car and tools) and was looking for inside photos to confirm the neutral and ground bar locations. Regarding an inspection… I understand why you didn’t get one done. The only concern I’ve really heard around this is related to insurance invalidation (should anything happen).

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