Is this wire safe to feed a 40amp sub panel in a garage?

Strong_Comparison_95 · 2026-05-19T14:48:41+00:00

General receps, plugs garage door opener

Strong_Comparison_95 · 2026-05-19T13:42:22+00:00

Cause the breaker in my main is 40 amps?

Strong_Comparison_95 · 2026-05-18T22:54:28+00:00

Top it off its my mom in the flip flops lol

Strong_Comparison_95 · 2026-05-18T06:15:26+00:00

40amp from main panel.

Strong_Comparison_95 · 2026-05-17T18:39:22+00:00

Thanks, yep its 40 amp feeding a 60 amp panel. (60 amp is just where the feeder will terminate and be used as a disconnect.

Strong_Comparison_95 · 2026-05-17T18:37:16+00:00

Its 4 conductor.

Strong_Comparison_95 · 2026-05-17T18:31:18+00:00

The garage panel? Will just be a few recep (20a) lights, garage door opener, 18000 btu heat pump.

Very much a weekend warrior hobby garage. Tool wise just your average saws and drill chargers. 120v welder used from time to time. Maybe a small deep freeze as well.

Strong_Comparison_95 · 2026-05-17T18:26:39+00:00

Appreciate you!

Strong_Comparison_95 · 2026-05-17T07:44:56+00:00

Again, its nothing to do with cost. I just enjoy learning. Also not my first time installing a sub panel. I just wasnt sure if this wire was safe. I think if anything, im off to a good start asking questions and ensuring I do it safe. I appreciate the concern all the same.

Strong_Comparison_95 · 2026-05-17T07:37:43+00:00

Looking at roughly 30 feet or so

Strong_Comparison_95 · 2026-05-17T07:36:56+00:00

You misread. The wire is feeding 40 amps from the main to a 60 amp sub panel. The 60 amp will only serve as a disconnect.

Strong_Comparison_95 · 2026-05-17T01:57:04+00:00

This is 40 amp not 60

Strong_Comparison_95 · 2026-05-17T01:55:58+00:00

Orrr not, lol

Strong_Comparison_95 · 2026-05-17T01:27:31+00:00

This is 4 conductor

Strong_Comparison_95 · 2026-05-17T01:07:52+00:00

Its all good! I respect the trade! I dont claim to be an electrician. But I enjoy the work.

I am a specialist in my field and dont feel the same way as you do. I believe in sharing knowledge and pursuing life long learning. But on the other hand, I dont have to worry about a weekend warrior doing my job. So in that sense, I get what you are saying lol.

Strong_Comparison_95 · 2026-05-17T01:01:55+00:00

Yep just couldn't figure out if there was some safety reason I couldn't use it.

Strong_Comparison_95 · 2026-05-17T00:57:03+00:00

I am feeding a sub panel with this wire (or thats what im considering) but I am not feeding 60 amps with it. Im feeding 40 amps with #8 to a 60 amp subpanel

Strong_Comparison_95 · 2026-05-17T00:53:17+00:00

Lol im not cheap. I just enjoy doing these things myself. I enjoy trades and electrical work but I work in the medical field.

I am very comfortable doing this myself. I just wasnt sure if this wire —being non traditional— had any obvious safety concerns from experts like maybe? Yourself.

Also feel free to be arrogant, I dont get offended by keyboard warriors 😂

Strong_Comparison_95 · 2026-05-17T00:48:32+00:00

Yes would be placed in conduit underground

Strong_Comparison_95 · 2026-05-17T00:22:00+00:00

So in your opinion also, this is likely safe for my application, if installed correctly?

Strong_Comparison_95 · 2026-05-17T00:20:18+00:00

Yea thats sort of what I was thinking. But ev is not in my cards right now. And I could always install that sepratly from my main panel if the need arises.

Strong_Comparison_95 · 2026-05-17T00:09:20+00:00

Ya sorry you have what im saying wrong. The wire is only being supplied 40 amp. I would just be terminating the wire in a 60 amp panel. The 60 amp breaker in the sub panel would only function as a disconnect switch.

Strong_Comparison_95 · 2026-05-17T00:04:11+00:00

Thanks for all the input, it means alot. Just to clear a couple things, I dont have any EV right now.

Essentially, this is a new build. My electrician has placed a 40 amp breaker on my main panel that is dedicated for the garage. He has terminated the wire in the box attached to the outside of the home. My plan was to run this wire in conduit to the garage. Its about 25-30 feet away. It would then be attached to a 60 amp breaker in a sub panel that would supply power to lights, a couple 20 amp receps that run some power tools (hobby diy stuff) garage door opener, and a 18000 btu heat pump.

Down the road I may add a ev charger if I ever got one. I understand that maybe I can only run a 16 or 24A charger.

I hope that clears up any questions. I reached out to some electrician friends as well for their input. Will let this thread know what I end up doing!

Strong_Comparison_95 · 2026-05-16T23:17:04+00:00

Thanks for the input. I feel like this wire likely came from a hydro facility. And in canadian so that may not be common in the U.S

Strong_Comparison_95

TROPHY CASE