220 line in the shop

Page 1 of 2  
Hi all,
My shop is located in the basement. Last year, we converted our hot water and range to natural gas, and as a result, I have these two nice junction boxes from the original 220 just waiting to be tapped with a nice big 3HP TS or something.
I was wondering if I could simply plug a 1PH 3HP power tool into one of the available boxes, or is there something more that I should be aware of?
Lou
BTW, saving about $20/month on electric bill so far, so I figure I'll break even when I'm 93.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
220 lines come in different amperages as you will likely find out when you try to match up the plug on the tool to the receptacle on the wall (different amperages use different shaped plugs). You need to make sure that the amperage required by the tool matches what the line is designed to supply. If the tool needs more amps than the line was designed for then you will need to run larger wires as well as replace the breaker and receptacle. If the tool needs fewer amps than the line was designed for then the wires should be fine but you may need a different breaker and receptacle.
- Bruce

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

True. You will likely have to put a new plug in the end of your power tool's cord

you
receptacle.
True, however a 3HP tool will require a double pole 20 Amp breaker, and any hot water heater or range is going to be at least 30 Amps. There will be more than enough juice there.

No .... do you install a 1-amp breaker to plug just a 100 watt table lamp into a circuit that happens to have nothing else attached?

Better yet: I'll bet that that range circuit it 50Amps. That should be plenty for a shop-only subpannel.
-Steve
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
When I was running a new 220 line for my tablesaw I was told by an electrician of long experience that I should not use a breaker and wire any larger than was necessary for the saw. I think his logic was along the lines of: if the saw motor gets overloaded you WANT the circuit breaker to trip to protect the motor. I realize this flies in the face of the way most household circuits work -- most of the loads on a typical 15A 110V household circuit are well below 15A -- and I cannot fully reconcile that discrepancy beyond saying that when running a dedicated circuit why not set it up so that it protects the motor and the rest of the electrical components of the tool as much as possible. Beyond that, all I can do is tell you what the electrician told me. If presented with the situation at hand I do not know if he would suggest installing a smaller breaker.
- Bruce

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Bruce Hooke" wrote in message

discrepancy
the
Because it is a fallacy to assume that the circuit breaker is there to protect the motor ... its sole purpose is to protect the insulation on the wiring of the shop/building.
--
www.e-woodshop.net
Last update: 10/04/04
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

any
Your electrician was wrong. Circuit breakers are not designed to protect motors against thermal overload - period.
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I may be misremembering his reasoning or he may have been wrong. He worked as an electrician for a number of decades but that does not mean he is perfect. What's more likely is that I am misremembering his reasoning.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

there are reasons to not oversize wires. they are things like bigger wire costs more and is harder to install. they are not things like bigger wire interferes with the ability of the circuit breaker to do it's job.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The reason my electrician gave for not oversizing the circuit was not the extra cost or difficulty of pulling the wires. But as I have now said over and over, all I am telling you is what an electrician of long experience told me. If you don't like what he said, so be it.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

There are plenty of electricians who have no business reason to understand all the intricacies of article 430. A lot of the finer points are really for designers and engineers, not installers. That is one reason why the manufacturer's instructions are usually the best guide. In the given situation, making a sub panel out of the range circuit may be the best choice, even if it only can serve 240v loads. (assuming no neutral is available and he wants to use the existing wire) Then he could install the NEMA 6-20 recomended by most machine manufacturers on 20a breakers.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 14 Oct 2004 04:07:16 GMT, snipped-for-privacy@aol.com (Greg) wrote:

I had the same dilemma.
As a new woodworker and needing a garage wired for power tools, I read the manuals and realized I had two choices. I could try to figure out where I wanted the nightmare of 10A/120, 15A/120, 20A/120, 15A/240, and 20A/240 or just go with 20A/110 and 20A/240 and let the breaker protect the wiring and box.
Supposedly, setting the breaker size to the motor, protects the motor from power surges. Being that the cost to run outlets galore in a mobile shop for ever possible combination would break the bank, I took my chances and went with all circuits at 20A in both voltages.
Warren
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 13 Oct 2004 13:48:57 -0400, loutent wrote:

Sounds like you hit a gold mine! Electric WH heaters generally require a 30AMP circuit and electric ranges are usually on a 50AMP circuit. If this is the case, you could put a subpanel on the end of the range circuit and expand from there for all your WW needs.
-Doug
--
"It has been a source of great pain to me to have met with so many among
[my] opponents who had not the liberality to distinguish between
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I had a similar situation, an unused 50A 220V circuit just sitting in my basement. Currently I am running a 2hp tablesaw from this circuit (with the appropriate recepticle/plug for 50A). I want to add a 220V powered dust collector now.
So is there a difference between installing a subpanel and then reinstalling 2 220V recepticles of lesser amperage and just wiring another 220V recepticle from the 220V recepticle that is currently running the tablesaw? The combined amperage would still be far less than 50 in either case. Is there some reason that each 220V recepticle should be on an individual circuit?
Hope this is not too dumb of a question.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 14 Oct 2004 10:22:58 -0700, snipped-for-privacy@yahoo.com (Jeff) wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The real issue is protecting the smallest conductor in the circuit from a short. The overload protection in your motor equipment should protect the motor. That all said, a sub panel with the proper breakers is the safest way to go and the only legal way if you are installing 15-20a receptacles. With 50a at your disposal you can install a pretty big sub panel as long as you know you will have load diversity (NEC speak for "not to much going at once") If you don't have a neutral and a ground this can only be a 240v panel, no 120v.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com (Greg) wrote in message

Yea, I have 2 hots and a ground from the large romex style cable. Would it matter where this subpanel was installed? In an unfinished stud wall using conduit out of the subpanel ok?
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Typically a water heater is run on a 30A circuit (10 gauge wire) and a range on either a 50A (old) or 60A (new) circuit. The 50A was often wired with 6 gauge aluminum and may not have a neutral; the 60A with 6 gauge copper.
You could certainly run a 3HP motor on either of those. If you insist on using the installed receptacles, you'll need to build a converter cable, but it's not a great feat to put in the receptacle of your choice with a little effort.
Really, everything is there; it's just a matter of safely mating the machine to the service.
- - LRod
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
http://www.woodbutcher.net
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Congrats on the conversion to gas, I think you'll like it. No reason not to use these boxes. You might want to install 220v outlets in convenient locations (and then some more!) in your shop. A 220v DC is great.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks everyone for the great info - seems like I'm ok to go for a new TS & DC - now just to decide on them!
Lou
BTW-we never run out of hot water with our gas heater - sometimes we did with the electric. Cooking with gas is WAY better (another hobby!)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
loutent woke up and had the following words of wisdom ....:

Sometimes when I claim " I cooking with gas now....." SWMBO just tells me to leave the room. I quite honestly think that it might be over-rated. ;-O
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.