To avoid these ads, REGISTER NOW!

Passed Cover Inspection

Kevin C

Well-known member
Joined
Aug 4, 2011
Messages
1,653
Location
Portland OR
Yesterday, the garage passed the cover inspection for the wiring on my 640 sq ft garage / gym / workshop. I got the inspector that is notorious for failing people. The only issue he had, was that I could swapped in duplex breakers after he left and then have more circuits than is allowed without a main disconnect.

Really? I could swap anything out once he left and be out of code. He let my "possible" violation go and commented that I didnt have to do all that work (I could have used Romex and not conduit).

He never asked any other questions about percentage box fill ( I added extension rings on two ceiling lighting boxes to meet code for box capacity), number of conductors per run... Just looked at it and said looks like you have the grounds tied, did you get all of them?

Why conduit? Besides being tough, if you want to upgrade your system its not that hard to pull another set of wires. Since I ran 3/4" in two loops, I should be able to easily expand. Also conduit has very low EMI, like 97% lower than Romex.

Since I like to tinker with electronics I'm kind of curious to see if I get any less 60 cycle noise when testing.

It did take a while but I think it was worth it. In the end I used about 260 feet of conduit and about 1200 feet 12 gauge wire. I have 15 outlets located in the work area (one 220V), 3 outside, six ceiling mounted for lighting and door openers and three in the attic.

I also mounted motion lights front and back, flood lights for the garden area and an entrance light for the patio.

One thing the inspector asked was what size breaker I had to power the panel in the garage. He looked at the wire gauge and asked if it was a 60 amp.

I said no, I used a 50 amp breaker. I'm surprised, because I thought that 6 gauge would be limited to 55 amps at 60°C, but he seemed to imply I could have used a 60 amp breaker. Is there some rule in the NEC that I missed?

Very glad that's done!

What I did learn is that it takes a lot longer to put in conduit. I have done small projects doing conduit but never a complete new building. The materials cost was not a big deal, but I'm sure glad I didnt have to pay for labor.

Now to pass the plumbing inspection.

Kevin
 
To avoid these ads, REGISTER NOW!
OP
K

Kevin C

Well-known member
Joined
Aug 4, 2011
Messages
1,653
Location
Portland OR
Why were you using the 60c rating?

I just figured it out....

The wire is rated for 90°C, I was de-rating for the termination at the breaker. I assumed that the breaker was rated at 60°C. I just went down and checked, my breakers are combo rated for 60°C / 75°C.

Assuming the panel meets the same 75°C rating and there are no other issues (like some rule that I dont know about that all the breakers need to be 75°C rated, you just never know), it looks like I can rate my wiring at 75°C / 65 Amp's.

http://www.iaei.org/magazine/2000/03/wire-temperature-ratings-and-terminations/

Good read.

Kevin
 
Last edited:

jeanty

New member
Joined
Apr 5, 2012
Messages
1
your idea is good . but why did use 260 feet of condiut about 1200 feet 12 gauge wire?:confused:
 
To avoid these ads, REGISTER NOW!
OP
K

Kevin C

Well-known member
Joined
Aug 4, 2011
Messages
1,653
Location
Portland OR
your idea is good . but why did use 260 feet of conduit about 1200 feet 12 gauge wire?:confused:

I was referring to the individual wires that pulled inside the conduit. As a minimum, each run has a ground wire and two power conductors. On my 26' x 24' shop it took about 100' of conduit to run the circumference. I figured that was at least 300 feet of wire pulled (ground white and black) for just one circuit.

The ceiling was another 70' of conduit for two openers and 10 four foot lights. The attic space used the rest.

What got me thinking about how much wire I used was that a couple of my 500' spools are just about empty. I thought that I had totally overbought when I got the larger spools, but it made sense since the cost per foot was a lot lower.

Running three lighting zones ate up a lot of material. Those runs got a ground, black ( for constant powered outlets used on the openers) three red wires for switched and a neutral.

I have done a lot of smaller projects but I have never wired a new shop from ground zero. As a newbie I was surprised at how much material it took to complete the job.

The upside is its done. It's great not having to navigate the driveway in the dark (motion sensing flood lights on the front of the shop).

I even set up an outdoor light on the side of the shop that's tied to the garage door remotes third button.


Kevin
 

PRH44

Well-known member
Joined
Dec 25, 2009
Messages
563
Location
Indiana
I just figured it out....

The wire is rated for 90°C, I was de-rating for the termination at the breaker. I assumed that the breaker was rated at 60°C. I just went down and checked, my breakers are combo rated for 60°C / 75°C.

Assuming the panel meets the same 75°C rating and there are no other issues (like some rule that I dont know about that all the breakers need to be 75°C rated, you just never know), it looks like I can rate my wiring at 75°C / 65 Amp's.

http://www.iaei.org/magazine/2000/03/wire-temperature-ratings-and-terminations/

Good read.

Kevin

Did you use #6 THHN/THWN copper in PVC conduit to feed your panel?
 
OP
K

Kevin C

Well-known member
Joined
Aug 4, 2011
Messages
1,653
Location
Portland OR
Yes, I used #6 copper THHN/THWN-2 in the PVC conduit to the panel.
 
Last edited:

Highbeam

Well-known member
Joined
Feb 15, 2011
Messages
2,292
Location
Mt Rainier foothills, WA
I used 6 gauge copper and a 60 amp breaker. That is acceptable because it is normally limited to 55 amps and you are allowed to use the next higher common size breaker.
 
To avoid these ads, REGISTER NOW!
Top Bottom