School me on wiring

[Hardcore]

My detached garage only has (2) 110v outlets on one wall. I need 220v power for my welder and some more 110v outlets on the other side of the garage. The 220 circuit breaker box on my house has a couple open spots. Can I run a 220V line from my breaker box on the side of my house, under ground, to the side of the garage and get both 110 and 220 power off of it. If I remember my electrical circuits class, a 220v service is (2) 110 volt lines? Correct?
Anyway, whats the easiest way to add a 220v outlet and (2) 110v outlets to my garage?

 

[jtlee]

you can either install a subpanel in your garage and have 120 and 240 available
or if you need just a single 240 outlet pull you some wire from breaker on house and feed your 240 outlet. for more 120 outlets feed them from your existing 120
outlets.( assuming that you dont overload the 120 volt wiring ampacity.

but if you got some spare change go ahead and install you a sub panel in the garage and then it will make future upgrades a breeze.

jt

 

[Pitalplace]

You can do your own wiring, but what I hear you saying would not meet code. You need a new box wired to the garage by a electritian. Then you could wire circiuts for the welder, lights and outlets. Remember home owner, farmer wired, not to code or without a permit may void your insurance.

 

[Rickster]

I was planning on bringing a 220 line from my laundry room dryer to my garage wall for the same thing. The dryer is gas and the 220 line is not being used. What size of 220 wire do I need to buy?

 

[Stuart in MN]

I was planning on bringing a 220 line from my laundry room dryer to my garage wall for the same thing. The dryer is gas and the 220 line is not being used. What size of 220 wire do I need to buy?

It depends...what size is the circuit breaker feeding the receptacle in the laundry room? What size circuit do you want in the garage? How far is it from the circuit breaker panel to the garage?

Assuming the existing circuit is 30 amps, and the total length of wire will be less than 100 feet, #10 gauge wire will be appropriate.

 

[Charles (in GA)]

Simply put, it sounds like you need an electrician. For a detached garage, consider one of two alternatives, depending on how much electrical load you anticipate in the future.

1) run a heavy feed to a subpanel in the garage, probably about 100 amps, if you don't expect to use much more than a small mig welder or a portable air compressor and a few lights and other power tools.

2) install a second meter, complete with a 200 amp panel in the garage with lots of circuit breakers for everything. This is the best course of action if you are planning on using a large fixed compressor, large welder, possibly an electric water heater, and other high draw items.

In my area, the meter charge is about $14 which includes the first few kw's of power, so most months I don't exceed $20 on my shop, unless I'm using the welder or the air compressor alot. I like having a separate source of power, its very handy when I have to shut off the house power to do electrical work, I just run a cord across the yard to the house for my work. Also was handy when the underground feed on my house burned thru on a weekend. The power company has a box that that takes the remaining leg and rephases it so I still had 220v, for about an hour until the remaining leg burned up from the overload on it. Then I ran a 12 gauge cord from the shop, on that other meter and plugged in the fridge and a couple of lights. Got me by till monday, when they came out and fixed the underground feed. Something to consider.

 

[TOMWELDS]

100amp line would cover all your needs...1 1/4" PVC conduit..3-#4 wires and 1-#8 ground..subpanel and a ground rod at the garage. Run an extra 1" conduit for phone, catv,etc..

 

[Charles (in GA)]

100amp line would cover all your needs...1 1/4" PVC conduit..3-#4 wires and 1-#8 ground..subpanel and a ground rod at the garage. Run an extra 1" conduit for phone, catv,etc..

Depending on the access to the main panel and the space in it for bending wires, what about 2-2-2-4 AL "mobile home" direct burial cable? Save the expense of the conduit.

Charles

 

[Mike F]

I thought I had read somewhere that code requires a burial depth of 24" for wire but if in conduit it is only 6". Is this true? If so, the cost of conduit is less than the "cost" to my back!! I'd go for the conduit.

 

[Charles (in GA)]

I thought I had read somewhere that code requires a burial depth of 24" for wire but if in conduit it is only 6". Is this true? If so, the cost of conduit is less than the "cost" to my back!! I'd go for the conduit.

I think I'd be digging it with a ditch witch, so it wouldn't matter.

Actually, with heavy steel (rigid metallic conduit or RMC) you can bury at 6 inchs, residential, but with PVC conduit ( rigid non-metallic conduit, RNC) you have to go 18 inches.

Direct burial cable under driveways, walks, parking pads are 18 inches (residential) but out in the open, direct burial is 24 inches.

Remember, all depths are to the TOP of the cable, so add a couple of inches to it.

You would have to weigh all the costs, CU vs AL, conduit plus wire vs direct burial cable cost, etc.

Charles

 

[Hardcore]

I am planning on adding a sub panel for my garage. My biggest question is, can a 220 volt, 100 amp line be split in the subpanel for 110v and 220v service?

 

[bmwpower]

I am planning on adding a sub panel for my garage. My biggest question is, can a 220 volt, 100 amp line be split in the subpanel for 110v and 220v service?

Tell me if this is right:

You will have a subpanel in the garage, which is fed from a 100amp line from the house. You want to know if you can have 220v circuits as well as 110v circuits running from the subpanel throughout the garage?

If so, the answer is yes, you can. A 110v circuit would only connect to one of the legs of the 220v from the subpanel. A 220v circuit "taps" into both 110v legs, therefore provides 220v to the circuit.

 

[Hardcore]

Tell me if this is right:

You will have a subpanel in the garage, which is fed from a 100amp line from the house. You want to know if you can have 220v circuits as well as 110v circuits running from the subpanel throughout the garage?

If so, the answer is yes, you can. A 110v circuit would only connect to one of the legs of the 220v from the subpanel. A 220v circuit "taps" into both 110v legs, therefore provides 220v to the circuit.

That's what I want to do.

My house has seperate panels for 220 and 110. I want to run a 100 amp line from the 220 box on my house into a new subpanel on the garage. In the garage subpanel I want to take this 220 line and run it to both 220v outlets (for my welder) and 110 outlets

 

[Charles (in GA)]

My house has seperate panels for 220 and 110. I want to run a 100 amp line from the 220 box on my house into a new subpanel on the garage. In the garage subpanel I want to take this 220 line and run it to both 220v outlets (for my welder) and 110 outlets

Kinda strange way to split up your panels, but your 110 panel (actually 120v) has 240v feeding it. The rows of breakers (breaker 1, top left, and breaker 2, top right, for example) are fed off of a single stab, which is one side of the 240v coming in. The next row down, (breakers 3 and 4) are fed from the next stab, which is off the opposite side of the 240v coming in. The rows alternate. Ganged 240v breakers pick off two electrically opposing stabs, giving you 240v.

You will take 240v which is two opposing hots, a netural (which you largely need only for the 120v circuits) and a ground..... out to the subpanel in the garage. You will also drive a ground rod (actually two or more to meet NEC) at the garage and connect to the ground bar in the panel. After doing this, you install 120v (single) breakers), and 240v (two breakers ganged together) as you need to supply your various circuits in the building.

Charles

 

[rawfish]

I think I'd be digging it with a ditch witch, so it wouldn't matter.

Actually, with heavy steel (rigid metallic conduit or RMC) you can bury at 6 inchs, residential, but with PVC conduit ( rigid non-metallic conduit, RNC) you have to go 18 inches.

Direct burial cable under driveways, walks, parking pads are 18 inches (residential) but out in the open, direct burial is 24 inches.

Remember, all depths are to the TOP of the cable, so add a couple of inches to it.

You would have to weigh all the costs, CU vs AL, conduit plus wire vs direct burial cable cost, etc.

Charles

Hi, I am curious as to why electrical cable needs to be buried at certain depths? Is it to ensure they don't get dug up/damaged easily in a shallow depth and hurt someone or is it something else?

 

[wyliesdiesels]

I noticed no one mentioned to the OP that he cant have more than one feed to a detached structure....

Of course, this thread is over 8 years old!

 

[Charles (in GA)]

I noticed no one mentioned to the OP that he cant have more than one feed to a detached structure....

Of course, this thread is over 8 years old!

When I started seeing my posts, I quickly looked at the dates and realized how old this thread is. Reading thru this, I was thinking the same thing, you cannot have but one circuit to the detached building (hot-neutral-hot-grd).

To answer the question posed by rawfish, simply put, the National Electric Code sets the specification. Indeed, the real reason has to do with protection of the circuits from people digging in the yard and such.

Charles