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Rezarf
09-22-2011, 11:42 AM
I am looking for some advice. I am trying to get a 220v line to my garage for my welder and (future) compressor. We just replaced our electric stove with a gas unit and I now have a perfectly good 220v 50amp circuit and wire just sitting there in the wall unused.

I ran my last 220v line from my fuse box to an outlet in the garage so I am not in totally new water here. However, I would like to run this by those smarter than myself.

If you pictured my house as a square, my stove is on the rear exterior wall. If I punch a hole through the exterior (which is where the existing outlet already sits, it just faces the interior) and pick up the circuit there, shouldn't I be able to run some conduit on the exterior of my home around to the garage (front right corner of the house when facing it). I figure the run of new cable to be about 65' and I would like to break off into two outlets one dedicated for the compressor and one for the welder, though the two will not be run at the same time.

Does this sound correct?

How do I start to figure out what gauge style wire I need? Thanks in advance-

Drew:thumb:

nuclearlemon
09-22-2011, 12:07 PM
i have one 220 that i alternate the welder and the compressor off of. i found that, since the welder always needs to be away from the corner where the compressor is, the easiest setup was an extension cord plugged into the 220 outlet and i alternate the compressor/welder from that. then i easily store the cord at the base of the compressor. this way, i can use the welder out in the driveway if i need.

Air Randy
09-22-2011, 12:13 PM
Drew,

Where is your AC distribution panel located? Rather than run a circuit from the existing receptacle location, run the circuit from the breaker panel itself especially if it is closer. As long as you have expansion space in your breaker panel, it is also very easy to add additional 220 breakers so you could have a dedicated circuit for both the compressor and the welder.

You can do what you propose very easily but you will need to use emt or rigid conduit and weatherproof fittings since it would be on the exterior. If you can run all of the circuit inside the house by going from the breaker panel you can useemt, pvc or even direct install without conduit.

The shorter the run of the circuit, the smaller the gauge of wire you can use. You will find the cost of wire per foot shoots up when you go from say 12ga to 10ga. It is like long thin sections of gold.

I've done a lot of wiring like this and I know how to do it so it is code compliant, if you need any help let me know.

I would have to look it up to be sure but I believe for a 50a circuit you need to use a 3+1 conductor 10ga wire when the run is 100' or less. Keep in mind too that 50a is probably way more than what you need for a compressor or newer welder. Usually a 30a circuit at 220v is more than enough. This can make a significant difference in the size/cost of the wire you use.

Beater
09-22-2011, 12:38 PM
stop by my house, and you'll see how I ran 70amp to my out-building according to code, suspended and all.

Rezarf
09-22-2011, 12:38 PM
Thanks guys, Randy, we don't have AC just a swamp cooler (which actually really impressed me on a few hot days).

I have a blank spot on my breaker labeled "Garage" that has been scratched out. I have searched high and low and can't find anything in the garage that would allow 220v access. The blank spot has two circuits marked off (for 220v) but they have a blank cover no breaker installed.

Ige, I like that idea a lot. I will most likely run a 220v outlet for the compressor into the attached shed behind the 3rd garage (where I will keep the compressor to cut the noise down) but I will most likely punch through the wall dividing the shed/garage and install one more outlet on the interior of the garage... along with an on/off switch to control the compressor power.

Jacket
09-22-2011, 01:06 PM
Do you have a basement that you could run the wiring instead of outside?

When I added my 220v, I did like Randy is suggesting. I left my dryer circuit as is, and dropped in a new 30 or 40A (can't remember) breaker to the panel, and then ran a short line of hard conduit through the wall and into my basement. I had something like 75' of wire to get from the panel to my garage, and I can't remember what I gauge I used - but I can check. I want to say it was 8g and it was pretty $$.

Air Randy
09-22-2011, 01:28 PM
[QUOTE=Rezarf;192338]Thanks guys, Randy, we don't have AC just a swamp cooler (which actually really impressed me on a few hot days). QUOTE]

AC distribution panel = breaker panel

HVAC = air conditioning :D

frontrange
09-22-2011, 02:36 PM
Copper will cost you an arm and a leg these days, I know because I just wired my new shop. Aluminum is way cheaper, but you cannot use it in a residence except between a main panel and a sub panel, which IMHO is a better way to go to power a shop.

I had electricians install a 70 foot 100 amp run through the attic to an 8 circuit sub panel in the basement for about $500 including parts just for reference, then I did a few short drops with large gauge copper from the sub panel to the compressor, welder and the machine tools.

Rezarf
09-22-2011, 09:56 PM
[QUOTE=Rezarf;192338]Thanks guys, Randy, we don't have AC just a swamp cooler (which actually really impressed me on a few hot days). QUOTE]

AC distribution panel = breaker panel

HVAC = air conditioning :D

DOH!

My breaker panel and garage are at the two opposite corners of the home. What a pain. I could drop the 50amp line inside into the basement since it is not finished and I can pull wire through it with ease. My dryer however is about 4' from the garage and would be a piece of cake to drop a circuit there.

Dave, I am in Broomfield now, not Louisville anymore if it makes a difference. And yeah, I pull permits... if I burn the place down they could come in handy ;)

DaveInDenver
09-22-2011, 10:58 PM
Unlikely to matter, I doubt any municipality has adopted the 2011 NEC yet and the vast majority of 2005, 2008 and 2011 hasn't changed.

FWIW, a 20% or less duty cycle allows an arc welder to be supplied based on 0.45 multiplier to the plate rating. So if the welder is rated 45A that means you only need to size the branch for 21A and can use a breaker sized at 200% of the conductor rating. Just don't exceed 2 minutes of use every 10. Even at 50% duty you can use a 0.71 multiplier and use a 30A sized branch.

frontrange
09-23-2011, 08:59 PM
Apologies for the hijack, but since you seem to know about service panels, a quick question. My new, nearly $6K rotary compressor has tripped it's 30 amp breaker 3 times now. It's supposed to be 5Hp, by my math that's a tad under 20 amps. Bad breaker???


Unlikely to matter, I doubt any municipality has adopted the 2011 NEC yet and the vast majority of 2005, 2008 and 2011 hasn't changed.

FWIW, a 20% or less duty cycle allows an arc welder to be supplied based on 0.45 multiplier to the plate rating. So if the welder is rated 45A that means you only need to size the branch for 21A and can use a breaker sized at 200% of the conductor rating. Just don't exceed 2 minutes of use every 10. Even at 50% duty you can use a 0.71 multiplier and use a 30A sized branch.

frontrange
09-24-2011, 08:35 AM
Single copper run, about 15 foot long. I can't remember the gauge, it's whatever was listed for 30 amps with copper, 10ga I think? There is a plug, I thought a disconnect was a code requirement.

Rezarf
01-02-2012, 11:55 AM
Bringing this one back to the top... I have done a lot of reading and understand a lot more than I did a few months ago.

My run from my main box is about 60' (+/-10') and I have access to the basement joists as it is unfinished (now). I am trying to decide if I want to run a dedicated 50amp line to the garage or run a subpanel. I haven't needed my compressor and welder at the same time yet, and doubt I will in the future.

So what say you? Subpanel? Or a direct line?

If I run either, what gauge should I be looking at? I was thinking 8/3 or 6/3 romex for a dedicated line or sub panel. I had a friend who does a lot of remodeling suggest wiring the subpanel with aluminum then running copper for two circuits from a sub panel.

Is aluminum wiring a no-no or in this case is it acceptable? I am hoping to knock this out this week. If I can/should use aluminum to run the subpanel, what size should I be looking at and what size sub panel should I buy? I am thinking 50 or 60amp sub panel.

Thanks in advance-

Mendocino
01-02-2012, 01:51 PM
I would suggest a sub-panel and use copper. I did the same thing in my garage and am very happy with the solution. My primary panel was really full and having the sub-panel is helpful.

Rezarf
01-02-2012, 02:52 PM
Thats a good reason Jeff however, I have like 5 open spots on my main at this point and I can't imagine expanding any more than that. The house is pretty complete.

Mendocino
01-02-2012, 06:08 PM
Thats a good reason Jeff however, I have like 5 open spots on my main at this point and I can't imagine expanding any more than that. The house is pretty complete.

You can never have to many lights...:D

black95
01-02-2012, 06:52 PM
Bringing this one back to the top... I have done a lot of reading and understand a lot more than I did a few months ago.

My run from my main box is about 60' (+/-10') and I have access to the basement joists as it is unfinished (now). I am trying to decide if I want to run a dedicated 50amp line to the garage or run a subpanel. I haven't needed my compressor and welder at the same time yet, and doubt I will in the future.

So what say you? Subpanel? Or a direct line?

If I run either, what gauge should I be looking at? I was thinking 8/3 or 6/3 romex for a dedicated line or sub panel. I had a friend who does a lot of remodeling suggest wiring the subpanel with aluminum then running copper for two circuits from a sub panel.

Is aluminum wiring a no-no or in this case is it acceptable? I am hoping to knock this out this week. If I can/should use aluminum to run the subpanel, what size should I be looking at and what size sub panel should I buy? I am thinking 50 or 60amp sub panel.

Thanks in advance-

I agree with your remodeler. Run 6/3 w/ground aluminum cable - preferably from your panel, from the stove outlet box only if you have to-- and add a sub panel on the 50 amp breaker. Wire everything from there with copper (you're not going to find aluminum in any gauge under #8 anyway). #10 for 30 amp, #12 for 20 amp, and #14 for 15 amp

If your range outlet is not a 4 wire outlet, you can't legally power a sub panel from it because you have to use the same wire for neutral and ground, and won't be able to bond the panel properly.

You can't run off of the 50 amp outlet and put in two smaller outlets from it because your 20 amp air compressor would burn the wire and your house down before it tripped that 50 amp breaker, this is especially true if you have a Federal Pacific panel.

If you run conduit outside on the house, you cannot legally put Romex/ indoor type cable in the conduit, so you have to use individual conductors, and that gets expensive.

Confused yet? I suggest you call an electrical contractor ;)

Panels are cheap, and very handy to have in the garage.

Luke - Colorado Master electrician #29754 :D

Rezarf
01-03-2012, 08:48 AM
I agree with your remodeler. Run 6/3 w/ground aluminum cable - preferably from your panel, from the stove outlet box only if you have to-- and add a sub panel on the 50 amp breaker. Wire everything from there with copper (you're not going to find aluminum in any gauge under #8 anyway). #10 for 30 amp, #12 for 20 amp, and #14 for 15 amp

If your range outlet is not a 4 wire outlet, you can't legally power a sub panel from it because you have to use the same wire for neutral and ground, and won't be able to bond the panel properly.

You can't run off of the 50 amp outlet and put in two smaller outlets from it because your 20 amp air compressor would burn the wire and your house down before it tripped that 50 amp breaker, this is especially true if you have a Federal Pacific panel.

If you run conduit outside on the house, you cannot legally put Romex/ indoor type cable in the conduit, so you have to use individual conductors, and that gets expensive.

Confused yet? I suggest you call an electrical contractor ;)

Panels are cheap, and very handy to have in the garage.

Luke - Colorado Master electrician #29754 :D

Thanks, I have ruled out the 50amp stove line. Something in me hates knowing there is an UNUSED 50amp line already run halfway through the house. Bummer, but your points make total sense, and in the long run it seems hodge-podge.

I have settled on a sub-panel with aluminum wiring to the panel then a few copper lines from there.

6-3 with ground AL SER
To my subpanel
Copper lines from there.

Sound good?

nakman
01-03-2012, 08:57 AM
Drew you're welcome to come stare at my setup if you want, we have very similar situations.

wesintl
01-03-2012, 11:31 AM
Drew you're welcome to come stare at my setup if you want, we have very similar situations.

REALLY? :eek: :lmao:

:beer: :D

Uncle Ben
01-03-2012, 11:36 AM
Drew you're welcome to come stare at my setup if you want, we have very similar situations.

:lmao::lmao::lmao::lmao::drumsticks::coffeescreen::hill:

nakman
01-03-2012, 12:45 PM
I'm missing the humor here. I have a sub panel wired with aluminum, aluminum ground, separate 220 for a welder... And I live a half mile away. :confused:

Rezarf
01-03-2012, 01:54 PM
I'm missing the humor here. I have a sub panel wired with aluminum, aluminum ground, separate 220 for a welder... And I live a half mile away. :confused:

Thanks Nak- I am going to take you up on that. PM inbound. :thumb:

Leave it to Kevin and Wes to turn it dirty... :rolleyes:

Rezarf
01-03-2012, 01:57 PM
On a 50amp feed breaker to a sub panel. How do you determine how big (amperage) the sub panel can be.

Say I want to run:

220v outlet for my welder
220v outlet for my compressor
220v outlet for a future heater (possible)
a few 20amp circuits for lights and outlets

I am struggling to see how they all go through a 50amp breaker.

thanks-

Rezarf
01-04-2012, 07:19 AM
I talked it over with a City Permit Building inspector yesterday and everything makes sense now. I appreciate it Nak, seeing it in person comfirmed everything I was thinking in my head.

Drew

Red_Chili
01-04-2012, 09:02 AM
I am struggling to see how they all go through a 50amp breaker.

thanks-
The assumption is, you don't run everything at once. I don't recall the load sizing rule of thumb though... 80%?

I know you can get away with load sizing that might not make sense for your situation. If you are welding thick steel while someone is running a plasma cutter pulling air, while in a cold January day, with all the lights on and the beer fridge chillin'... you might have issues. :lmao:

black95
01-04-2012, 09:40 AM
On a 50amp feed breaker to a sub panel. How do you determine how big (amperage) the sub panel can be.

Say I want to run:

220v outlet for my welder
220v outlet for my compressor
220v outlet for a future heater (possible)
a few 20amp circuits for lights and outlets

I am struggling to see how they all go through a 50amp breaker.

thanks-

Red Chili is right. The general rule is 80%. So, if you can only put 24 amps on a 30 amp breaker, 16 amps on a 20 amp breaker, 12 amps on a 15. Now this is based off of continuous duty, or more than 3 hours of use. A 20 amp breaker can hold 20 amps, maybe even 25, for a short time before it heats up. The rule breaker on than is motors. You can size a motor breakers much higher because of startup inrush current, and a 10 amp motor can trip a 20 amp breaker on startup... but I'm not even going to open that can of worms.

It seems confusing when you're looking at a 50 amp panel, and see 2 double pole 30's, a double pole 20, and 4 single pole 20's... thinking that will never work, but it does. whatever is on that 30 should never pull more than 24 amps, or the breaker is sized wrong.

I have a 50 amp sub panel in my garage that feeds a 22 amp forced air heater (EVERYONE should have one of these :) ), my 185 Hobart mig, a 30 gallon twin cylinder air compressor, a 30 amp RV outlet, a beer refrigerator, and all of my outlets. I never have any problems. The last solid axle swap we did, we had a guy on a grinder, one on a plasma cutter, and me on the welder with the heater running... nothing ever tripped.

Your panel rating will be determined by the wire and breaker size, most likely 50 amps. You could go 60 amp, but then you would almost have to use copper or you'd be looking at pulling #4 aluminum SEC, and that would suck.

I don't even think you can buy a panel that is rated less than 100 amps anymore. I would shop at Home Depot and get a panel that matches the brand currently in your house. Maybe a 12 or 18 circuit. You do not need a main breaker in the new panel, the breaker you put in your main panel takes care of that. Do not put the bonding screw in the panel, and separate your grounds and neutrals. You may have to pull a bar out of the panel that crosses over between the grounds an neutrals to do this, or you may have to buy a separate grounding kit. If you need any help, just let me know.

Rezarf
01-04-2012, 10:28 PM
Red Chili is right. The general rule is 80%. So, if you can only put 24 amps on a 30 amp breaker, 16 amps on a 20 amp breaker, 12 amps on a 15. Now this is based off of continuous duty, or more than 3 hours of use. A 20 amp breaker can hold 20 amps, maybe even 25, for a short time before it heats up. The rule breaker on than is motors. You can size a motor breakers much higher because of startup inrush current, and a 10 amp motor can trip a 20 amp breaker on startup... but I'm not even going to open that can of worms.

It seems confusing when you're looking at a 50 amp panel, and see 2 double pole 30's, a double pole 20, and 4 single pole 20's... thinking that will never work, but it does. whatever is on that 30 should never pull more than 24 amps, or the breaker is sized wrong.

I have a 50 amp sub panel in my garage that feeds a 22 amp forced air heater (EVERYONE should have one of these :) ), my 185 Hobart mig, a 30 gallon twin cylinder air compressor, a 30 amp RV outlet, a beer refrigerator, and all of my outlets. I never have any problems. The last solid axle swap we did, we had a guy on a grinder, one on a plasma cutter, and me on the welder with the heater running... nothing ever tripped.

Your panel rating will be determined by the wire and breaker size, most likely 50 amps. You could go 60 amp, but then you would almost have to use copper or you'd be looking at pulling #4 aluminum SEC, and that would suck.

I don't even think you can buy a panel that is rated less than 100 amps anymore. I would shop at Home Depot and get a panel that matches the brand currently in your house. Maybe a 12 or 18 circuit. You do not need a main breaker in the new panel, the breaker you put in your main panel takes care of that. Do not put the bonding screw in the panel, and separate your grounds and neutrals. You may have to pull a bar out of the panel that crosses over between the grounds an neutrals to do this, or you may have to buy a separate grounding kit. If you need any help, just let me know.

Thanks man-

I think I am ready to dive in, I finally understand all the lingo... everything you said makes sense and is part of my plan. I am going to run 3-6 Aluminum with a ground to run the sub panel. I am going to use a 50amp breaker to feed it.

Tell me more about your heater, and or do you have a link? Thanks!

black95
01-05-2012, 08:07 PM
I bought this heater from Northern tool:

http://www.northerntool.com/shop/tools/product_595_595

Phenomenal heater. I'm usually in a tee shirt in 10-15 minutes. (Should be noted that I have an insulated garage door) Had a 5 foot baseboard heater in my garage before that, and it murdered my electric bill. This heater, I don't even notice on the bill.

They also had this model that I almost went with because it's a lot cheaper, but the reviews were too good on the other. Made to be free standing, but could be hung on a home made bracket easily.

http://www.northerntool.com/shop/tools/product_200395481_200395481

Not sure what the difference could be, almost same specs. maybe louder and worse quality? Is it cheaper because it's not designed to be ceiling mounted? who knows. I love the heater I bought, and it's very, very quiet.

Glad I could help, good luck. :)