Running a 220 line out the garage - sanity check!

Ok, so I'm getting really close to taking the plunge and running a 220 line out to my detached garage, and was hoping that someone could point out if there are any no-no's in my plan.

The garage is detached and run will be about 50 feet from main to sub panel. My plan is to run 220 and 110 from this sub. There is also an existing 20 amp circuit in the garage. I'd like to keep this circuit as well, but it won't be used for brewing.

• I'll run 4 - 6 gauge THWN stranded wires in 1 1/4 PVC conduit
• Conduit will be buried at least 18"
• The line will come from my main panel (50amp 2 pole break), to the outside and connect to a 50 amp SPA GFCI, like one of these. Then the cable will go underground to the garage.
• In the garage the line will come up outside to a junction box then through the wall in the garage to a sub panel.
• Ground and neutral will be separated. My understanding is no ground rod is needed.

As far as the load, I'd be looking at a 4500 (maybe 5500) watt element on the 220, and maybe a 2000 element running on 110. I'd like to do as much of work as I can.

Am I missing anything, or any glaring problems / concerns?

ur kinda goin overkill with 4-6 gauge wire... 8 gauge would be sufficient for a 50 amp breaker. i certainly wouldn't use 4 gauge.

It sounds like you have it figured out.Can't see any problems,go for it. Is the garage sheetrocked or going to be?? Because if you are not going to rock, you will have to use bx(armored cable, mc cable) and keep any horizontal runs of cable above 8 feet for the garages internal wiring.If i were closer I'd come by and give you a hand!

#8 is only good for 40 amps

GranillaNutz said:

ur kinda goin overkill with 4-6 gauge wire... 8 gauge would be sufficient for a 50 amp breaker. i certainly wouldn't use 4 gauge.

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Sorry I meant 4 (2 hots, neutral, ground) single 6 gauge wires. I have someone who I can buy the 6 or 8 gauge wire off of for basically the same price, so I figured what the heck. The only difference that I could see was possibly needing a larger conduit.

DemonCleaner said:

It sounds like you have it figured out.Can't see any problems,go for it. Is the garage sheetrocked or going to be?? Because if you are not going to rock, you will have to use bx(armored cable, mc cable) and keep any horizontal runs of cable above 8 feet for the garages internal wiring.If i were closer I'd come by and give you a hand!

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Thanks or the info. I wasn't aware about the 8 foot limit. The entire garage isn't and won't be sheetrocked, but the area where the subpanel and my outlets (for this new 220 line) will be.

Sounds like a plan to me. As far as running to my garage from the main breaker (a 100A unit), I just called the electrician. He told me I might as well get the subpanel for the garage and install it myself, because I could get it cheaper than his contractor wholesale if I bought it at Menards or Lowe's. He ran the cable to the subpanel I'd put in, and I did the other wiring myself.....which I've done before. No sheetrock is involved, but it's a steel Morton building, so there was no trouble with a handy horizontal above 8 feet to run all the wire. I then just used regular conduit to bring the wire down to the boxes, pretty much like any of the photos online showing such installs. This system gives me enough amps that I have the option of running 220V for brewing, welding, plasma cutter, etc. (although not simultaneously, of course).

You may or may not need a ground rod. In Maryland a groundrod is required as well as the ground you bring from your house panel to any detached structure. (MI may be different.). Other than that I think you are doing just fine....Although if your going to run 6 copper....why not just use a 60 amp breaker?......

Hammy71 said:

You may or may not need a ground rod. In Maryland a groundrod is required as well as the ground you bring from your house panel to any detached structure. (MI may be different.). Other than that I think you are doing just fine....Although if your going to run 6 copper....why not just use a 60 amp breaker?......

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Thanks, I'll check out if a ground rod is required. Regarding the 60 amp, it seems the last time I was at homedepot a 60 amp GFCI was quite a bit more than a 50 amp, and seeing that I don't really need it anyway, I was going to just stick with 50 for now.

I'm pretty sure a ground rod and simultaneous disconnecting means is required if you have more than 1 circuit going to a separate building.

I'd suggest going the panel route with a main breaker and recircuiting the existing receptacle (and lighting??) circuit.

Edit: This may require a permit as well. Also, are you sure the load on your main panel can handle this additional load?

If you're going to the trouble of burying the wire, why not set a subpanel out there and run your circuits out of that???


Also, if you are digging a trench, you might as well drop a 3/4 PVC pipe in the trench for phone and cable. As long as you have the trench open, now's the time. You may not want to run the cables at this time, but at least the conduit will be there if you want to do it in the future.

I put an additional ground on the sub panel in my garage. The cost is minimal.

You should verify that 18" meets code for depth. I know here in Ontario is has to be deeper, and dip down where the cable enters the building. I don't know what the building codes are like over there.

dave

Do check codes. I did a similar project recently. I think I had to be down 18" or something like that. I should have run it in conduit but used direct bury cable instead. I put a subpanel out in the garage. I highly suggest running it in conduit so you could pull more later.

I would go directly from your 50 amp breaker in the main panel out to the garage, install the subpanel there, have the 50 amp GFCI breaker there plus the breaker for your 20 amp circuit.

+1 on putting the subpanel in the garage, running an extra piece of 3/4" for phone (internet) connection, as well as the ground rod. I just did a lot of underground for my shop, etc... Most of the literature said use a ground rod in a case like yours and some of them even said to carry an extra ground. I belive the ground could be a couple of sizes smaller but don't remember the specifics. One of the real electricians on the board can explain that to us. I know all of these suggestions sound like a lot but since you've alrady got the trench, it's no big deal. Good luck on whatever you decide - Dwain

Thanks again, fellas... definitely appreciate it.

I am for sure putting the subpanel in garage, sorry if I didn't mention that earlier.

- I know I had read a many people suggesting the GFCI before the cable the entered the ground, in the event you severed the cable. Thinking about this now, this was probably for UF without conduit, or if you weren't able to bury the conduit deep enough. I'll move it into the sub.

- Grounding rod - It turns out I do need one, maybe two in the detached building. I'll add this to the list.

- Also, good thought about the extra conduit. I'll never use it for phone (cell phones only) or internet (wireless), but cable might be a future option. much more graceful than a 60ft RG6 cable across the lawn. Good call.

Bernie Brewer said:

If you're going to the trouble of burying the wire, why not set a subpanel out there and run your circuits out of that???


Also, if you are digging a trench, you might as well drop a 3/4 PVC pipe in the trench for phone and cable. As long as you have the trench open, now's the time. You may not want to run the cables at this time, but at least the conduit will be there if you want to do it in the future.

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+1 This an easier way. Just run the wire and set a panel in the garage, and from there you can get 220/110 from it. I totally agree with dropping a 3/4" conduit for data/phone- if not now, then future.

HomebrewJeff said:

• I'll run 4 - 6 gauge THWN stranded wires in 1 1/4 PVC conduit
  

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I am not at all knowlegable about this, but wouldn't you want solid wire? Forgive the off topic comment, but just curious. Inside the house, walls, I thought needed to be solid.

Like I said I no nothing about it, just something I heard.

u shouldn't need a ground rod if it's a subpanel. you'll only need ground rods at the point of origin (your main service). chances are it's allready grounded sufficiently. i've never heard of having to put another ground rod just because the building is detatched. after all, the wire u run will have a ground that will bond to your original system. are you getting this inspected? you can use 8 gauge copper wire on a 50 amp breaker. just depends on the situation.
According to the NEC
Table 310.16 Allowable Ampacities of Insulated Conductors Rated 0 Through 2000 Volts, 60°C Through 90°C (140°F Through 194°F), Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried), Based on Ambient Temperature of 30°C (86°F)
Types RHW, THHW, THW, THWN, XHHW, USE, ZW
For 60°C (140°F) is 40 amp
And for 75°C (167°F) is 50 amp
Also from the NEC 2002 book
8 AWG THHN, 90°C copper wire is limited to 40 amperes where connected to a disconnect switch with terminals rated at 60°C. This same 8 AWG THHN, 90°C wire is limited to 50 Amp
i use 10 gauge on a 50 amp breaker for my brew equipment. under just about a full load for an hour the wire doesn't even get warm.
the price difference prolly isn't that much.
and i wouldn't run data and phone in the same trench as the feeder. get static if they're too close.

Sean said:

I am not at all knowlegable about this, but wouldn't you want solid wire? Forgive the off topic comment, but just curious. Inside the house, walls, I thought needed to be solid.

Like I said I no nothing about it, just something I heard.

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Stranded is a bit more flexible, so it's much easier to pull through conduit, especially when you have a couple of bends. It's just going from one breaker to the other.

GranillaNutz said:

u shouldn't need a ground rod if it's a subpanel. you'll only need ground rods at the point of origin (your main service). chances are it's allready grounded sufficiently. i've never heard of having to put another ground rod just because the building is detatched. after all, the wire u run will have a ground that will bond to your original system. are you getting this inspected? you can use 8 gauge copper wire on a 50 amp breaker. just depends on the situation.

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From what i understand, this is for lightning protection.

if your entire system is properly bonded and grounded at the point of origin, i just don't see the point in putting in a separate grounding system. but if you're not an electrician, and you don't know if your system is properly grounded, then, yes, it would be a good idea to put another ground rod. according to NEC it's not necessary, but each jurisdiction makes it own rules and can override the NEC. each county and parish has it's different things that u can and can't do. most of it is really nitpicky and is being VERY overcautious.

GranillaNutz said:

u shouldn't need a ground rod if it's a subpanel. you'll only need ground rods at the point of origin (your main service). chances are it's allready grounded sufficiently. i've never heard of having to put another ground rod just because the building is detatched. after all, the wire u run will have a ground that will bond to your original system. are you getting this inspected? you can use 8 gauge copper wire on a 50 amp breaker.

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To be honest, this depends on the inspector. I've had inspectors that insisted on two groundrods on an outbuilding subpanel. Then on a different project in the same municipality a different inspector asked me why I bothered with groundrods in the exact same situation. Just put in a couple rods 6' apart and you're covered.

GranillaNutz said:

if your entire system is properly bonded and grounded at the point of origin, i just don't see the point in putting in a separate grounding system. but if you're not an electrician, and you don't know if your system is properly grounded, then, yes, it would be a good idea to put another ground rod. according to NEC it's not necessary, but each jurisdiction makes it own rules and can override the NEC. each county and parish has it's different things that u can and can't do. most of it is really nitpicky and is being VERY overcautious.

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True- which is why I'm thankful we're out in the country in a rural county and we have no codes, much less inspectors. Don't get me wrong- I have everything done per NEC, but some of the municipalities can get so wacky, I'm just glad I don't live in one. My favorite story was an electrical engineer friend living in an area town who was putting a hot tub out on his porch, which had aluminum screens set in the wooden porch construction. The city inspector wanted him to ground all the aluminum screens. He replied "Why, so I can be electrocuted more efficiently?"

While all the electricians are here, I have a related question. I already have 240v in my garage, but I want to run a cable from the sub panel to my proposed electric rig. Eventually I will be running (2) 5.5kw 240v heating elements and (2) 240v march pumps. What cable do I need to run between the sub panel in the garage and the new control panel for the rig?

GranillaNutz said:

and i wouldn't run data and phone in the same trench as the feeder. get static if they're too close.

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Should be fine if the data is a co-ax cable.

Laughing_Gnome_Invisible said:

While all the electricians are here, I have a related question. I already have 240v in my garage, but I want to run a cable from the sub panel to my proposed electric rig. Eventually I will be running (2) 5.5kw 240v heating elements and (2) 240v march pumps. What cable do I need to run between the sub panel in the garage and the new control panel for the rig?

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What's the load on the 2 pumps?

GranillaNutz said:

u shouldn't need a ground rod if it's a subpanel. you'll only need ground rods at the point of origin (your main service). chances are it's allready grounded sufficiently. i've never heard of having to put another ground rod just because the building is detatched.

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Check out section 250.32. This section covers buildings supplied by feeders or branch circuits. (I'm looking at the 2005 NEC which does have some additions from the 2002.)

If only one branch circuit is fed from the house panel to the detached garage, no separate grounding is required, but if you're putting a sub panel in, this is now considered to be a feeder and grounding is required per this section.

Apollo said:

What's the load on the 2 pumps?

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They are both 1.25 horse power. Won't the horses eat my grain?

Laughing_Gnome_Invisible said:

They are both 1.25 horse power. Won't the horses eat my grain?

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Just the loads are about 66A, with a small safety factor, 69.5A. #4's on a 70A breaker should work. If you wanted a little extra, you could do #2's on up to 100A breaker.

The horses won't only eat your grain, they'll drink your beer too.

gl finding a 70 amp breaker

boy i wish i could edit that last post... whoooops