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Another Sub-Panel Question

countrysquire

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League City, TX
Looking at running a sub-panel from my main breaker panel to my detached garage, which, naturally, is on the complete opposite corner of the house from the service entrance. I think that I can easily get by with 60 amps, though more might be better. Looking at my city's website, it states that "No aluminum wire shall be used past the supply side of the meter at any premises, except for temporary services and construction feeders." Based on that, it sounds like I will be using copper, so is NM-B what I need or something else?
 
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Stuff

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Detached means cable has to go outside so you can not use NM. UF-B is is available in 6 gauge for 55 amp feeder on a 60 amp breaker. Better to use conduit and individual conductors.
 

wyliesdiesels

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Modesto, CA
Looking at running a sub-panel from my main breaker panel to my detached garage, which, naturally, is on the complete opposite corner of the house from the service entrance. I think that I can easily get by with 60 amps, though more might be better. Looking at my city's website, it states that "No aluminum wire shall be used past the supply side of the meter at any premises, except for temporary services and construction feeders." Based on that, it sounds like I will be using copper, so is NM-B what I need or something else?

Agree with above. Run conduit and individual THWN conductors.

U will need 2 ground rods, an isolated neutral bar in the subpanel along with a ground bar, usually purchased separately.
 
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countrysquire

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Yes, I can use conduit. The garage is attached, but is really separate from the house. Conduit from the breaker box to the garage, routed under the eave should be straight forward. I didn't consider the option of using individual conductors.

Is 1" conduit large enough for four individual #6 conductors?
 
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ddawg16

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Is your garage attached or detached? Big difference on wiring.

If the garage is physically touching your house (excluding a covered walkway), it's attached. In other words, is there a shared wall? If no shared wall, then it's detached.

A sub panel in an attached structure does not need the ground rods. You use the ground from your main panel.

Detached....do it as wd noted above.

Yes, 1" is ok....personally, I'd go 1 1/4". Cost difference is minimal and makes the pull a lot easier.

And personally, wouldn't run it under the eves....unless that is the only way. I'd want it in the ground or attic. If the garage is detached, then it will have to be in the ground.

For your wire, 2 black #6's, THHN/THWN, 1 white #6 and a green or bare ground wire. I think #10 is enough.

And if you are going to be running conduit....consider a second one for Ethernet cable.

BTW....if you have more than 4 turns (elbows), then you will need a pull box along the way.
 

wyliesdiesels

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Yes, I can use conduit. The garage is attached, but is really separate from the house. Conduit from the breaker box to the garage, routed under the eave should be straight forward. I didn't consider the option of using individual conductors.

Is 1" conduit large enough for four individual #6 conductors?

So which is it? Attached or detached.

Yes u should be able to fit 3 #6 and a #10 for the EGC in 1" using a 60a breaker.

Is your garage attached or detached? Big difference on wiring.

If the garage is physically touching your house (excluding a covered walkway), it's attached. In other words, is there a shared wall? If no shared wall, then it's detached.

A sub panel in an attached structure does not need the ground rods. You use the ground from your main panel.

Detached....do it as wd noted above.

Yes, 1" is ok....personally, I'd go 1 1/4". Cost difference is minimal and makes the pull a lot easier.

And personally, wouldn't run it under the eves....unless that is the only way. I'd want it in the ground or attic. If the garage is detached, then it will have to be in the ground.

For your wire, 2 black #6's, THHN/THWN, 1 white #6 and a green or bare ground wire. I think #10 is enough.

And if you are going to be running conduit....consider a second one for Ethernet cable.

BTW....if you have more than 4 turns (elbows), then you will need a pull box along the way.

not always the case. Some AHJs consider a garage connected by a breezeway roof as attached.
 
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countrysquire

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I guess it depends on the definition of detached. There is a short section about 6 foot wide and attaches the house to the garage, but also about a 25 foot section of roof that they share. The existing wiring feeding the garage is Romex and goes through that six-foot wide section.


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countrysquire

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Hopefully a photo will help.
9a670da1ed3d1f43e7ff9ca5927c85c6.jpg




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Beemer533

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If the existing wiring is nm-b then it seems likely that it would be considered attached, assuming the wiring was permitted..
 

theoldwizard1

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SE MI
The existing wiring feeding the garage is Romex and goes through that six-foot wide section.

If you can run your new wire in the same route, then you can use NM-B.




Never hears of a local code that bans aluminum wire. IIRC, a sub panel is treated as a branch circuit.
 

ddawg16

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So which is it? Attached or detached.

Yes u should be able to fit 3 #6 and a #10 for the EGC in 1" using a 60a breaker.



not always the case. Some AHJs consider a garage connected by a breezeway roof as attached.

True.

I'm inclined to say the above garage is attached based on the pic. Not much a separation.
 
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countrysquire

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Thanks guys. So considering it as an attached building, then no additional ground rods at the sub panel end, just an isolated neutral bar, correct?


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Aceman

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Eastern Oregon
Is there an attic between the house and garage where a cable could be fished in? I would never run a conduit down the exterior of a customers home unless they held a gun to my head and there was no other way.

1. Attic/crawlspace
2. Underground
3. Surface mount conduit

That would be my preference, in order.
 

theoldwizard1

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SE MI
Is there an attic between the house and garage where a cable could be fished in?

If there is an attic between the house and garage the MUST be a fire rated wall. Any hole in a fire rated wall must be sealed with fire resistant caulk/foam.
 
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