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-   -   Main box feeding 220v and 110v brearker box off a 50am breaker? (http://www.diychatroom.com/f18/main-box-feeding-220v-110v-brearker-box-off-50am-breaker-54884/)

uvamosk 10-10-2009 10:04 PM

Main box feeding 220v and 110v brearker box off a 50am breaker?
 
Hello Everyone,
I just purchased a 220v welder as I am starting to get more into welding and have completed my welding class.

Buying a 220v welder I knew I didn't have a 220v supply in my garage so I started reading into it but I have a few questions I need to iron out before I start on this project.

Before I start: I am going to do all the wiring and get as much ready as I can. Then I am going to call in a electrician to check it all and give me the OK and to hook it up to the main panel.


Here is what I'm thinking:
I have room to put in a Double Pole 50amp breaker in my main box in the house.

I was going to run 10/3 4wire cable in PVC tubing underground.

I was going to use a Disconnect and hook up a breaker box in the garage.

I was going to see if I can find a 50amp main breaker for the box and then run 220v with 30amp circuit for the welder and 2 110v 20amp circuit for power tools.
Also of course this box would have grounding rods hooked up.

I am going to make all connections properly and using the right boxes and everything.. So don't think this is going to be a hack job.

I Just wanted to make sure this was the correct train of thought. The garage will see light use mostly just welding. I'm not running a shop or anything where I have to worry about a huge pull on the breaker. Just figured a 50amp breaker would be good enough to supply everything. Might also run another 220v one day.

Scuba_Dave 10-10-2009 10:11 PM

You can't use 10-3 for 50 amps, probably more like #6 wire
Is the garage attached, detached? - you say underground so I think detached
With a sub panel in a detached structure you will need grounding rods
You need to run 4 wires & that will be a 240v sub
Grounds & neutrals on seperate buss, neutral buss not grounded to the case

uvamosk 10-10-2009 10:30 PM

Yeah I figured I would have something wrong lol thats why I was checking.

I figured it would have to be bigger than 10 gauge but I wanted to check.

Other than that it sounds like I'm on the right path.
I will be using grounding rods as it is a detached and I'll be running #6 also.
All my hook-up's also seem to be in the right order.

Other than the #6 everything I described should be good to go?

Scuba_Dave 10-10-2009 10:37 PM

Yes #6 is good for 55a, so a 50a breaker would be fine
2 black #6 hots
1 white #6 neutral
1 green #10 (I used #8) ground

Ground to rods needs to be #6 min - I used #4

How far to the garage?

uvamosk 10-10-2009 10:54 PM

I'm looking at probably less than 100 feet I have to measure tomorrow for sure. I'm pretty sure it will be under 100 feet. You know how much #6 goes for per foot?

Back when I was just going to run a 10/3 220v to the garage I was looking at 4 wire cable that had a outdoor coating. I was going to use it and bury it in PVC conduit.

It his advised and if so does #6 come in that same setup.

uvamosk 10-10-2009 11:01 PM

How much does #6 go for average per foot?

Plumbvoltage 10-11-2009 10:13 AM

Quote:

Originally Posted by uvamosk (Post 338965)
How much does #6 go for average per foot?

#6 copper is approx $ 0.60 to $ 0.85 per foot.

frenchelectrican 10-11-2009 12:45 PM

The price will varies depending if you use the UF route or THHN/THWN in conduit so look around.

Most big box store do sell roll of conductors or cable they typically come in 25 , 50 ,100, 250 , 500 even 1000 foots spools

So you can get one close to what you need it. somecase you may want to order extra you have to remember the burial depth that can really screw up the count of mesure if not watching it carefully with it.

Merci,Marc

J. V. 10-11-2009 12:58 PM

Hold on a minute! Welders are addressed as special equipment in the NEC and are treated differently than other equipment or appliances. For one a welder is duty rated. So it does not need to be protected the same as continuous duty equipment or appliances.

You have not told us whats on the welder nameplate. We need that to tell you what size breaker and what size wire. In some instances a breaker much larger than would normally be allowed would be allowed. Welders are one of them. What does the manufacturer say. They usually provide breaker and wire sizes for their welders?

I agree with Dave regarding the sub panel. This is no time to skimp. You must by code install at minimum a 60 amp panel in the unattached structure. So install a 60 amp feeder to a sub panel in the building. Use 1" conduit and four seperate lengths of THHN/THWH wire. 2-Blacks/1 white/1 green. (#6). Two ground rods connected to grounding strip in the sub panel. I would use bare #6 for the ground rods. Keep them next to each other. You need a main breaker panel or a disconnect.

Note: Using the search function above, search "sub panel" or "wire garage" or "run wire to garage". Keywords like that will get you more information than you can read. Concentrate on your feeder and sub panel first. Then get all the information on the welder. We will work on the welder, once you get the sub installed and ready.

uvamosk 10-11-2009 01:17 PM

Well the welder is rated for a 30amp breaker. It's a Hobart and they say no bigger than 30amp that's the reason I said it would be on a 30 amp. So I have to run at least a 60amp to the sub panel and in it. I can't even find a 60 amp double pull at the store only 50

Speedy Petey 10-11-2009 02:17 PM

Quote:

Originally Posted by J. V. (Post 339136)
Hold on a minute! Welders are addressed as special equipment in the NEC and are treated differently than other equipment or appliances. For one a welder is duty rated. So it does not need to be protected the same as continuous duty equipment or appliances.

You have not told us whats on the welder nameplate. We need that to tell you what size breaker and what size wire. In some instances a breaker much larger than would normally be allowed would be allowed. Welders are one of them. What does the manufacturer say. They usually provide breaker and wire sizes for their welders?

IMO this only applies if you are wiring the welder in a commercial setting where there is control over the receptacle and how it is used, or if the welder is hard wired with a disconnect.

If this will simply be a receptacle for a plug-in welder in a residence I personally don't feel the special stipulations in Art.630 (Welders) should be used.

J. V. 10-11-2009 02:23 PM

How many spaces in the 50 amp main breaker panel? You could use 50 amp, if it provides enough room for the breakers you are going to use plus a few spares? The welder will take two slots. I would think a 60 amp panel would be common. Maybe not. Check another supply house.

You could use a 100 amp main breaker panel (very inexpensive) and and feed it with a 60 amp feeder. Or feed it with a 100 amp feeder. It all depends on what you plan to do in this building. If you are going to have a few appliances, some tools, the welder, 100 amp seems like it would be the way to go. Then you have all the room you need, plus room to add more later.

Since the welder calls for a 30 amp breaker you would normally use #10 wire. You may be able to use smaller wire. Depending on the amp rating of the welder.

J. V. 10-11-2009 02:26 PM

Quote:

Originally Posted by Speedy Petey (Post 339173)
IMO this only applies if you are wiring the welder in a commercial setting where there is control over the receptacle and how it is used, or if the welder is hard wired with a disconnect.

If this will simply be a receptacle for a plug-in welder in a residence I personally don't feel the special stipulations in Art.630 (Welders) should be used.

I agree. But he did not say anything regarding the welder except it required a 30 amp breaker. Point well taken Speedy. Thanks.

OP......You reading this?

Scuba_Dave 10-11-2009 02:36 PM

60a 240v breakers are common here at HD
The sub panel can be a 100a panel & feed it with 60a
Buy a main breaker 100a panel, the 100a main breaker will serve as the disconnect

uvamosk 10-12-2009 12:08 PM

I got ya, so using the 100amp panel it serves as the disconnect. I was at lowes the had a DP60amp in thick but I needed thin. I'll check HD. So I should still use #6 wire right. I was looking for some at lowes guy there said I could use 6/3 would that be advised as this is just a garage power source for light use.

On a side note if I bring in a 220 and feed a subpanel then run some 110v plugs will running a tool while welding lead to any issues with the welder? Since they share the same feeder breaker from my main box.
Just asking as I want the welder to preform at it's best. I could just run a 220v straight to the welder if I had to as there is 110v in the garage now.


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