Detached garage 40 amp feed

[Hibou]

I've been reading this board for a bit, but I can't seem to get a definite answer for my situation, as strait forward as many will likely see. Sorry in advance for the "grounding question" that seems to come up quite a bit. I'll try to be as detailed as possible without being too wordy...

I've newly built a detached 20x24 detached garage with light loft. It's situated 22 feet from my house, and the main panel in my house is another 20 feet away. The house is 3 years old, 200 amp panel with lots of room. I live in Canada.

I have installed a 8/3 wire (2 hots, 1 neutral, 1 ground) into a 1" pvc conduit undergroud from the house to the garage. I also have a 14/2 wire going from the garage to the house to controle the garages exterior lights from the house (switch in house). I have a 40 amp double pole breaker for my main house panel (not installed) to feed the garage. I have 2 15 amp breakers for my 100 amp sub-panel (not installed). I'm not planning to run anything extreem, but I will eventually have a 240v outlet for utility (occasional use) heater or tools. At the moment, I will be running lights and outlets.

My understanding is the install is strait forward. Run the 2 hots, the neutral and ground from the main panel to the sub panel. In the sub-panel, the 2 hots go to their respective spots, and the neutral goes to the neutral bus, the ground to the ground bus. Am I right? Will this setup be safe? Or, should I look into installing a ground pin? Isn't the ground through the 8/3 feed from the house enough? If a ground pin is needed (or highly recommended), does that alter the sub-panel feed and how?

Many thanks!

 

[Falcon67]

Not sure about Canada, but here I have the same setup with a 100A feed and I used 30' of $4 copper in the slab as a ground. I would ground the building and make sure you keep the neutral buss separate from the breaker box frame.

 

[MrMark]

You are all correct. The ground is back through the main panel to the neutral on the utility. The ground pin has nothing to do with clearing ground faults. It is for lightning )(mainly) and so the neutral stays clamped to Earth potential. Don't get worked up about the stupid ground pin! Just drive it in and be happy.

 

[tfi racing]

Up here a "ground pin"(no such thing,BTW) is not required and is in most cases against code for a detached building subfed from your main service.The bonding conductor in your cable is sufficient.Hopefully you have used the required NMWU cable,if so,it must have been fun jamming it through that 1" PVC with a 14/2...

 

[acer66]

I hope I do understand this right, it is okay to run a wire back to the house from the garage
because it is dead when you hit the main breaker at the house?

 

[Hibou]

Thanks for all the replies.


So, the final question is: do I need a "ground pin" (or whatever it's called) or don't I?


The 14/2 wire running back to the house is fed from the garage sub-panel for the purpose of controlling outside garage lights only from the house.


Yes, it was quite fun to fish both the 8/3 and 14/2 into the 1" pvc conduit. Looking back, 1.5" conduit would have been better. Good thing it's not a long run (22 feet).


The 8/3 wire supplied by the store is standard NMD90 (white), and not NMWU (black). They told be that as long as it's in a conduit then it is fine. I got this same info from a few places in town.

Again, many thanks!

 

[jvitez]

The 8/3 wire supplied by the store is standard NMD90 (white), and not NMWU (black). They told be that as long as it's in a conduit then it is fine. I got this same info from a few places in town.

NMD-90 stands for non metallic sheathed cable, DRY, rated to 90 deg. NMWU is non metallic sheathed cable, wet, underground. NMD-90 is only for above ground dry indoor use. Methinks you'll need to replace the cable.

Check this out for Winnipeg's regulations:

http://www.winnipeg.ca/ppd/pdf_files/HOElec.pdf

Anything underground will get wet, conduit or no.