[Boss hog]

Hello... I have questions about installing a sub panel to detached garage. The garage already has the wiring ran but the sub panel needs replaced and I'm rewiring the entire garage.

Here are the details:
- garage will only run lights, table saw, compressor, etc ( nothing much more than that)
- pre existing wiring from shop to house is 4 awg ( 3 wires = 2 copper hots, 1 aluminum neutral?) on a double pole 50 amp breaker at the house panel.

The plan:
- install 100 amp sub panel (with grounding bar and neutrals separated )
- install copper grounding rod

The questions:
- sub panel : main breaker or main lug ?
- is the wiring size and type ok?

I appreciate it !!

 

[jbfan]

You need a 4th wire from the main panel, other wise your plan is sound.

How far from the main?

I would use the al to pull a new cooper neutral and ground wire.

Main breaker, and it is used as a disconnect.

 

[Boss hog]

Thanks.
The garage is about 50 if I had to guess.
The 3 wires that are ran are sorta twisted together, I guess to pull the wires easier ... So I doubt I'd be able to pull new wires using the al wire. Any other ways to run a ground wire? Or should I just pull all the wires and replace with new?

 

[jbfan]

Thanks.
The garage is about 50 if I had to guess.
The 3 wires that are ran are sorta twisted together, I guess to pull the wires easier ... So I doubt I'd be able to pull new wires using the al wire. Any other ways to run a ground wire? Or should I just pull all the wires and replace with new?

Depends on the money you want to spend.

Myself, I would pull it out, sell the wire and buy 2 black, 1 white #6, and a green #10.

I don't know how long it has been there or the size of the pipe, so pulling it out may not be the best idea,.

 

[Oso954]

- install copper grounding rod

You should install 2 copper ground rods at least 6ft apart.

 

[Boss hog]

I def don't want to spend money that's not needed but pulling new wires may be the only way to get a ground from house to garage.

The pipe size is 1 1/2 - 2 ".... I'd have to look again.
Not sure how hard it would be to pull new wires , I've never pulled wire that size that distance before.

 

[Boss hog]

Thank u sir... Yea I knew some places require 2 ground rods... I haven't check ours to see what's required (Alabama). But I'd def check before I install it.

 

[Oso954]

Assuming Alabama is on the NEC, you can have one ground rod if it tests less than 25 ohms. Otherwise you must drive the second rod.

As the test costs a lot more than a 2nd rod, most people just drive 2 and done.

 

[Boss hog]

Thanks.. That will be in my check list.

Apparently it was code to run 3 wire feeders when this was run... Code changed to 4 wire in 2008.
(Which I'm prob stating fact you all know already)
With a 4 wire feeder (which is code now) u would separate neutral and ground at the sub panel.
3 wire feeder u would keep both neutral and ground bar intact.

Would this be wise to keep the 3 wire feeder?

If not any pointers to pull new wires?

 

[Oso954]

You should upgrade to the 4wire feed. Like Jbfan, I would replace all 4 conductors.
With the newer slick coatings on the THWN, I think you'll find the new wire easier pulling than the old conductors.

Attach a pull rope to the old conductors so you will be pulling it thru as you pull the old conductors out.

 

[Boss hog]

Ok sounds good... Id like to run new wiring anyways just didn't wanna spend $500 bucks on wire lol

Would 6 awg be sufficient ?
100 amp sub panel?
Main breaker instead of main lug? (Even tho the 50amp breaker at the house is the disconnect for the sub panel)

Just trying to make a list of things .

 

[Jim Port]

The #6 would be fine as long as you limit the feed breaker to 50 or 60 amps.

If you have a subpanel you need a disconnect at the shed also.

 

[Boss hog]

I appreciate it... I got all new cables ready to go and will pull them threw soon... There is only one underground conduit and it runs under the concrete driveway... I want to get Ethernet cable ran to the garage and that's the only path... So if I ran an Ethernet cable with the feeder wires what would happen? Interference with data? Just wondering if there is a danger to it. I'd rather run it now if there is no danger. If I were running conduit I would separate them but under this circumstance not sure what else to do.