Wiring 220 for welder & compressor

[shaun]

I got a great deal on a 2 stage compressor for the shop, now I have to wire it in. Its got a 16.5amp sticker on the motor plate.

I bought a 30amp breaker and 100' of 10/3 wire. The compressor will sit at the opposite end of the shop from the panel, approx. 60' of wire away. Along the way I was going to branch off the run and install a welder outlet for a 220 welder down the road. I wouldn't consider the branch for the welder except this is my last 2 open slots and the 30amp breaker will fill my panel.

2 questions really:

1, Is that a safe practice having a branch like this?
2, So long as both appliances don't run at the same time, I should be ok right? What amperage welder could I run at the same time as the compressor?

 

[Lyaec350]

It's unlikely you'd be welding and running the compressor at the same time, but you would be wise to not use anything that pulls more than 14 amps if the compressor is rated at 16 amps. Additionally, that 16 amps is probably running current not starting current so you'd be even more limited. 30 amps is a bit small for a 220V welder, I know my Hobart IronMan 210 wanted a 50amp plug.

 

[PurdueSD]

My miller 212 only takes a 30A plug... Just make sure your put a disconnect at your compressor, so you can flip the switch before firing up the welder.

 

[SteveU]

2 questions really:

1, Is that a safe practice having a branch like this?
2, So long as both appliances don't run at the same time, I should be ok right? What amperage welder could I run at the same time as the compressor?

My miller 212 only takes a 30A plug... Just make sure your put a disconnect at your compressor, so you can flip the switch before firing up the welder.

I agree with PurdueSD, either put a disconnect in or physically walk over to the compressor and turn it off before doing any welding. The reason for this is that even though you are not using the compressor at the same time as you are welding it may be right on the verge of kicking in & a very slight leak somewhere in the piping will cause it to kick on & overload your breaker. As long as you ensure this doesn't happen & the breaker is sized large enough for both this shouldn't be a problem. When I bought my house they had the electric range & the dryer ran like this, lived here 5 yrs before I upgraded the service and each got their own circuit.

 

[kvom]

You put a switch on the compressor side of the outlet.

 

[shaun]

Where do I find a 220 switch?

I was hoping a simple toggle switch like a light switch would work.

 

[timgr]

You can buy 30A 240V wall switch at your local electrician supply. They are available online too - I bought a few through MSC Direct.

 

[buening]

You can also get the disconnects at your local box store. Here is a picture as an example. I have one on the wall that is wired to the compressor, and they are often used at central air conditioners by code.

 

[shaun]

You can buy 30A 240V wall switch at your local electrician supply. They are available online too - I bought a few through MSC Direct.

Got a link or picture? I'm having trouble finding them online.

 

[timgr]

Catalog page 3356.
http://www1.mscdirect.com/CGI/NNSRI...opmainPcircularid=13665Ppagenumber=3344Pmode=

 

[shaun]

Catalog page 3356.
http://www1.mscdirect.com/CGI/NNSRI...opmainPcircularid=13665Ppagenumber=3344Pmode=

That is more like it! Thanks!

 

[sberry]

Your Ironman 210 has a 50A plug but requires only 30A service. Good time to install an additional 6 space panel to gain some extra spaces or free up a couple by using tandem breakers for a couple 120V circuits, my preference is a panel as breakers are expensive. I don't like 2 appliances running from one wire, a panel in this class is cheap, some as low as 20$ + a ground bar kit. Use a number 6/3 wg wire and feed with a 60A breaker, no more expense than buying extra switches and making a cobbled up mess that still isn't really right.

 

[toadjammer]

That switch that is linked won't work, it is only a single pole. You will need a double pole if such thing exists.

 

[toadjammer]

Here is one that is double pole:
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1941876&PMT4NO=0

 

[shaun]

Here is one that is double pole:
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1941876&PMT4NO=0

I spoke with MSC, they said that switch was only good up to 2Hp, my motor is 4Hp.

He recommended this:

http://www.hubbellcatalog.com/wiring/section-c-datasheet.asp?FAM=Switches&PN=HBLDS6

MSC quoted me $386!

 

[toadjammer]

Well the one listed is for 3 pole or 3 phase. You didn't say you were running 3 Phase, maybe the salesam inferred this info. I have no idea why the wall switch isn't sufficiant heck you stated the tag rating as 16.5 amps and the one I listed is 30 amp capacity and all of this is rated per pole. If you are really dead set on using a disconect type you can go to your local building supply HD/Lowes?Menards and get a 30-50 AMP disconect like used for an exterior hot tub it will have a curcuit breaker in it to kill the power.

Doesn't your air compressor have an off switch?

 

[shaun]

Well the one listed is for 3 pole or 3 phase. You didn't say you were running 3 Phase, maybe the salesam inferred this info. I have no idea why the wall switch isn't sufficiant heck you stated the tag rating as 16.5 amps and the one I listed is 30 amp capacity and all of this is rated per pole. If you are really dead set on using a disconect type you can go to your local building supply HD/Lowes?Menards and get a 30-50 AMP disconect like used for an exterior hot tub it will have a curcuit breaker in it to kill the power.

Doesn't your air compressor have an off switch?

No off switch. I'm using it just regular 220v, not 3 phase...

 

[Hatman52]

Good time to install an additional 6 space panel to gain some extra spaces or free up a couple by using tandem breakers for a couple 120V circuits, my preference is a panel as breakers are expensive. I don't like 2 appliances running from one wire, a panel in this class is cheap, some as low as 20$ + a ground bar kit. Use a number 6/3 wg wire and feed with a 60A breaker, no more expense than buying extra switches and making a cobbled up mess that still isn't really right.

I agree. If your existing panel is full, either replace it with a new panel with more spaces, or add another panel. The first option is neater and cleaner, but requires more electrical knowledge, the second is easier. Both will end up costing about the same if you do it yourself, and neither will be much more expensive than what you're talking about doing, particularly if you have to source a 220v switch/disconnect. Plus, this will give you more flexibility to add circuits in the future.

While "sharing" your 220v/30 amp circuit wouldn't meet NEC, it isn't unsafe, as long as you remember to turn off the compressor. At some point, of course, you'll forget, and the breaker will pop right as you're in the middle of welding. I vote for doing it right the first time.

 

[mad57]

I think at least 6-3 should be used for that distance if under 50 amps, most welders i see are at least a 50 amp breaker, my hobart is 52 amp peak so i went with 2-2-2-4 with 60 amp breaker to sub panel ( just the same lenght as you are) then from sub panels extra 8 spaces to plasma , lift, explosion proof fan. with 6-3. good luck.mike this is best way to go and to code in nj.

 

[Mike in Ohio]

Change the plug on the welder or on the compressor so they take the same receptacle then only install one. That way you have to unplug one to use the other. That is what I did in dads garage because he had a very small panel and didn't ant to change it out. Mike

 

[bop_pa]

Are you sure 10-3 is sufficeint wire size. I seem to remember my 2 stage compressor wanted #8 or #6. Might double check the instructions.. (Note.. I am not an electrician, just want you to double check)

 

[shaun]

So I found this at Lowes for $7!

Its a non-fused AC dissconnect rated for 60amps, 2 phase for motors up to 10Hp. It has a handy on/off switch on it.

Unless somebody knows of a good reason why this wouldn't work, I'm going to use it and feel pretty happy with myself knowing I saved a ton of money.

 

[hetkind]

Expect to use your welder and air compressor at the same time...as in sandblasting for weld prep, using air powered cut off wheels, air grinders and sanders.

I had the same basic disconnect box on my air compressor, and in fact, code requires away of switching aircompressors and welders.

NEC has a special table on feeds for welders and air compressors depending on duty cycle, but 10 gauge might be a tad small.

Howard

 

[royalton10]

Can the disconnect similar to picture at tail end of thread be used as a junction box to do 2 wire runs on opposite side of 24x24 shop to wire outlets for welder or air compressor? One wire in from service panel, one wire out to one outlet, another wire out to another outlet?

Thanks!!

 

[shaun]

So I found this at Lowes for $7!

Its a non-fused AC dissconnect rated for 60amps, 2 phase for motors up to 10Hp. It has a handy on/off switch on it.

Unless somebody knows of a good reason why this wouldn't work, I'm going to use it and feel pretty happy with myself knowing I saved a ton of money.

Been using this all year with no problems. Many, many, many hours sand blasting. No welding on the same circuit yet though...