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Electrical question on 220

You can have more than one 220v outlet on a single circuit as long as you don't exceed the capacity of the circuit. If you have your compressor and lathe on the same circuit and the compressor starts while the lathe is running, you might overload the circuit and pop the breaker.

I have my jointer, planer, bandsaw and table saw on the same 220v circuit but I never run more than one at a time.
 
There are always a lot of thing you CAN do and probably get away with it but the real question is whether it's a good idea or not and why. If you have a home depot in your area just ask their electrical professional and he can give you some good feedback. Otherwise just talk to any electrical professional that you trust and they will usually give you advise.
 
When I got my PM3520B a year ago (same sale they have now) I bit the bullet and had a dedicated line brought in with its own breaker. I have two outlets for it along one wall and added a switch for both. I dont like leaving the electronic unit on when its not being used so on my way out of the shop I hit the switch, kill the juice to the unit and the second switch kills the spots I also use.

I have no windows in the shop, so one dedicated line is for ceiling lights, one dedicated line is for the dust system and a third line is for the other power tools ( I never operate more than one power tool at a time except for the dust system). Now I have a fourth line for the lathe and just last week added a fifth for hand corded tools. I have almost as many breakers for the shop as the entire house. Of course, i cant run the coffee pot AND the microwave or the toaster at the same time. Only two at a time.
 
You can, but you might not want to. If the existing circuit is up to code it was designed with a breaker/fuse to protect the wire in the wall. It may not be the right size for the lathe. If it is to small it will trip, to large and it won't protect your lathe. Also, I use my compressor a lot when I use the lathe. One circuit might not be enough for both.

As Laurence has done, I also put a switch in the circuit for convenience and safety. I also like turning the electronics off when not in use.

If you are not comfortable adding a circuit, hire a licensed electrician. If you do it yourself remember that grounding is very important!
 
Laurence Giglio said:
When I got my PM3520B a year ago (same sale they have now) I bit the bullet and had a dedicated line brought in with its own breaker. I have two outlets for it along one wall and added a switch for both. I dont like leaving the electronic unit on when its not being used so on my way out of the shop I hit the switch, kill the juice to the unit and the second switch kills the spots I also use.

I have no windows in the shop, so one dedicated line is for ceiling lights, one dedicated line is for the dust system and a third line is for the other power tools ( I never operate more than one power tool at a time except for the dust system). Now I have a fourth line for the lathe and just last week added a fifth for hand corded tools. I have almost as many breakers for the shop as the entire house. Of course, i cant run the coffee pot AND the microwave or the toaster at the same time. Only two at a time.
Click to expand...

Thanks for the ideas. Looks like a new circuit and switch. This new lathe would mean 3 tools on 240 at the same time (DC, compressor and lathe) and that don't feel good.
 
Gerald Lawrence said:
Thanks for the ideas. Looks like a new circuit and switch. This new lathe would mean 3 tools on 240 at the same time (DC, compressor and lathe) and that don't feel good.
Click to expand...

Consider running two 220 lines.

It is maybe a 1/3 more work to run two lines at the same time.
If you are hiring the work it should be cheaper than 2x one line. A lot of their expense is the road time and service call fee.

Someday you may have a big bandsaw or a second lathe.....

And for now you can have the DC and compressor in separate lines.
 
I do have one 220 outlet in my shop that multi-tasks, but it has only one plug in so there is no chance of overloading the circuit. Every other machine is on a dedicated circuit. I did it right the first time. I had a 200 amp sub panel put in. Next shop will have more than that.

robo hippy
 
For me its this, I know little about electricity except that touching two lines at one time is a bad thing. I was fortunate, the panel for the house is on the same wall as the lathe, its in the garage (shop) and I had several unused breaker spots. So adding circuits while not cheap for it to be done by an electrician saves me worries about something going wrong and the garage burning down. I have several 20 amp 110 volt lines for power tools, several 15 amp 110 volt lines for hand tools and a seperate line for lights. In my previous house, i had one circuit for all, and when I was making my benchtop many years ago and ripping 8/4 hard maple, the circuit blew, the lights went out and there I am in the dark in a crowded garage. I knew if I reset the breaker to see, the saw would have kicked back on, it didnt have a mag switch. So I slowly pulled the board out, then reset the breaker. You will save money on the PM, spend some of what your saving and get it done right. Its worth it. And do what I did, have it done while the lathe is being shipped, so when it gets there, its got power! You need to get the cord plug since it doesnt come with the lathe. Get it and the lock twist type plug.
 
Laurence Giglio said:
For me its this, I know little about electricity except that touching two lines at one time is a bad thing. I was fortunate, the panel for the house is on the same wall as the lathe, its in the garage (shop) and I had several unused breaker spots. So adding circuits while not cheap for it to be done by an electrician saves me worries about something going wrong and the garage burning down. I have several 20 amp 110 volt lines for power tools, several 15 amp 110 volt lines for hand tools and a seperate line for lights. In my previous house, i had one circuit for all, and when I was making my benchtop many years ago and ripping 8/4 hard maple, the circuit blew, the lights went out and there I am in the dark in a crowded garage. I knew if I reset the breaker to see, the saw would have kicked back on, it didnt have a mag switch. So I slowly pulled the board out, then reset the breaker. You will save money on the PM, spend some of what your saving and get it done right. Its worth it. And do what I did, have it done while the lathe is being shipped, so when it gets there, its got power! You need to get the cord plug since it doesnt come with the lathe. Get it and the lock twist type plug.
Click to expand...

maybe I'm missing something here - but if the breaker trips while saw is running, you have 2 options:

1. turn off the switch on the saw before resetting the breaker.
2. unplug the saw before resetting the breaker.

😛
 
Shawn Pachlhofer said:
maybe I'm missing something here - but if the breaker trips while saw is running, you have 2 options:

1. turn off the switch on the saw before resetting the breaker.
2. unplug the saw before resetting the breaker.

😛
Click to expand...

Tools with a magnetic starter have contacts that change states when power is lost, requiring the start button to be pressed to start when power is restored.
 
Laurence Giglio said:
For me its this, I know little about electricity except that touching two lines at one time is a bad thing. I was fortunate, the panel for the house is on the same wall as the lathe, its in the garage (shop) and I had several unused breaker spots. So adding circuits while not cheap for it to be done by an electrician saves me worries about something going wrong and the garage burning down. I have several 20 amp 110 volt lines for power tools, several 15 amp 110 volt lines for hand tools and a seperate line for lights. In my previous house, i had one circuit for all, and when I was making my benchtop many years ago and ripping 8/4 hard maple, the circuit blew, the lights went out and there I am in the dark in a crowded garage. I knew if I reset the breaker to see, the saw would have kicked back on, it didnt have a mag switch. So I slowly pulled the board out, then reset the breaker. You will save money on the PM, spend some of what your saving and get it done right. Its worth it. And do what I did, have it done while the lathe is being shipped, so when it gets there, its got power! You need to get the cord plug since it doesnt come with the lathe. Get it and the lock twist type plug.
Click to expand...

In addition to what you said there at least a couple more reasons to having the wiring done right.

  1. If you ever sell the home, any non-compliant wiring will need to be done correctly.
  2. If you ever have a fire and the subsequent investigation reveals bootleg wiring, even if not directly related to the cause, it might jeopardize the insurance claim.
Anybody who does wiring by the seat of their pants and gauges success on whether it works ought to seriously consider getting a qualified second opinion (meaning a licensed contractor or a city inspector).
 
If you can't get another dedicated line what I did is I put a on-off-on switch in the single line just before the outlet box. Only the unit on the on side gets power so it's ether compressor OR lathe never both.
I now have dedicated 220v 20 amp lines for Band saw, Dust collector, lathe General,lathe Vega,lathe Union Graduate. I can run DC + 2 other lines at once,which is Ok for a one man shop. My whole shop is on a 60 amp circuit off the main so the 3 ceiling lights stay on if I blow something(there on the main) and when I leave the shop I flip the 60amp breaker and all shop is shut off.
This has worked great for me and my insurance agent said it's what they like to see no one there no power on except emergence lighting.
 
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I just wired in a new 220 to my shop.cost less than 40.00. You have 3 things on one curcuit..put in a new one
 
Harry Robinette said:
If you can't get another dedicated line what I did is I put a on-off-on switch in the single line just before the outlet box. Only the unit on the on side gets power so it's ether compressor OR lathe never both.
I now have dedicated 220v 20 amp lines for Band saw, Dust collector, lathe General,lathe Vega,lathe Union Graduate. I can run DC + 2 other lines at once,which is Ok for a one man shop. My whole shop is on a 60 amp circuit off the main so the 3 ceiling lights stay on if I blow something(there on the main) and when I leave the shop I flip the 60amp breaker and all shop is shut off.
This has worked great for me and my insurance agent said it's what they like to see no one there no power on except emergence lighting.
Click to expand...

What kind of switch are you using between the two outlets?

As for using the sub-panel 60A main breaker as a shut-off switch, I would suggest that you use a switch designed for that purpose instead -- something similar to the image below is what I have in mind.

Square%20D%20600v.jpg


The reason that I suggest using an enclosed knife switch is that circuit breakers do not hold up well if used as a switch and a 60A double pole main disconnect breaker is very expensive to replace. What typically happens whether the breaker is manually tripped or if it trips from overload current is that it eventually begins false tripping at a much lower current level than its rated current. A person would not normally be aware of that until the breaker reaches the point of nuisance tripping for no reason. All of the false tripping can lead to thinking that there is some problem with the motor when it actually is perfectly fine.

Your insurance agent is undoubtedly a great guy, but probably not an authoritative source when it comes to questions about electrical installation.
 
Bill
My system was built as good as I could at the time.A friend just told me about that knife switch and how it will help with the ageing of the breaker. Thanks for the info. My insurance man said that having a main switch is just something that most of them like to see.The switch on the line is just a 220 on-off-on I got from ebay a couple years ago.
 
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I don't know about your state building codes, but when I wired my shop I checked with the building inspector and found that it is OK to have multiple outlets on a 220v line. I also had the wiring inspected after it was complete and passed without a problem.

Sure, it is nice to have individual lines for each tool, but it isn't necessary. In 5 years I haven't tripped the breaker once.
 
Michael Mendelsohn said:
I don't know about your state building codes, but when I wired my shop I checked with the building inspector and found that it is OK to have multiple outlets on a 220v line. I also had the wiring inspected after it was complete and passed without a problem.

Sure, it is nice to have individual lines for each tool, but it isn't necessary. In 5 years I haven't tripped the breaker once.
Click to expand...

In some cases that would be fine, but not always.

Fire safety is what the electrical inspector and codes are concerned with. They are concerned with protecting the wire in the wall, not if the circuit will protect your equipment. If the multiple outlets is for equipment that is not used at the same time it wouldn't be a problem. If the machines on a single circuit are being used at the same time and not tripping, there is probably very little overload protection for the equipment.
 
Do you have a separate circuit for each appliance in your kitchen? It depends on how many amps you pull continuously.
Your more apt to trip a breaker in your kitchen than you are the shop.
Ask an electrician, run the wires and circuits, then pay the electrician to come out, check it out, and hook it up to the panel.
 
Don't get me wrong, I'm no expert electrician so this is a question more than a statement. If you are running two pieces equipment on the same line, even if they are not on at the same time, and one of them pulls 15 amps but the other one pulls 30 amps aren't you asking for trouble? You have no overload protection on the smaller machine.
 
Brian McInturff said:
Do you have a separate circuit for each appliance in your kitchen? It depends on how many amps you pull continuously.
Your more apt to trip a breaker in your kitchen than you are the shop.
Ask an electrician, run the wires and circuits, then pay the electrician to come out, check it out, and hook it up to the panel.
Click to expand...

The NEC is very clear on this question. Each and every fixed appliance in the home must have its own dedicated branch circuit. Just to help clear up any misconceptions, a toaster, wok, Fry Baby, blender, and mixer are portable devices. Your clother washer, dryer, dishwasher, undersink disposal, oven, range, water heater, Jacuzzi, central HVAC, window air conditioner, refrigerator, etc are fixed appliances.

The answer that James gave is mostly correct. Safety (not just fire safety) is the whole purpose of the NEC. The code is concerned more than simply the building's wiring installation because safety is impacted if a piece of equipment fails, but doesn't trip the branch circuit breaker. I havent been following code updates for the last decade or so, but the branch circuit breaker size for a fixed appliance is supposed to be rated at something like 120% of the maximum current of the appliance. My memory is a bit fuzzy on how machines in a home workshop are treated and different jurisdictions probably have differences in their requirements, BUT smart design would be to plan your design with some forethought of what machine will be used in which location and size the branch circuits accordingly. If you really want to protect more than just the wiring in the walls then think about the great advantage of having individual branch circuits for large machines that provide a meaningful level of protection for the machine as well. It would be a good idea to create individual branch circuits for things like tablesaws, planers, jointers, bandsaws, and lathes that have 240 VAC motors rated at 2 HP or more (or even 1 HP, if you wish).

To clear up another misconception, the ampacity of your sub-panel does not need to be equal to the sum of all the branch circuit breakers (unless you plan to have all machines going simultaneously). Do a real world assessment plus allowance for expansion and larger machines plus a little extra. No doubt the sum of all the branch circuit breakers will be greater than the main disconnect of the panel.

Rules of thumb are often applied such as when sizing the service entrance panel. There are at least two methods of doing this and they are basically based on the square footage of the living space plus requirements of certain fixed appliances that all homes would have. Having room for growth is always better than wishing that you had done it.
 
Bill,
Not sure the fridge and window air require their on dedicated line unless they are 220. And, I'm not sure shop equipments are considered "fixed". I'll have to ask my electrical guy at work tomorrow.
 
Brian McInturff said:
Bill,
Not sure the fridge and window air require their on dedicated line unless they are 220. And, I'm not sure shop equipments are considered "fixed". I'll have to ask my electrical guy at work tomorrow.
Click to expand...

I am pretty sure that the fridge has its own branch circuit, but as I said about machines in the shop, it is smart to have individual branch circuits for large machines even though they aren't technically "fixed". A properly sized breaker might save your tablesaw or lathe from becoming completely toasted if it has a malfunction.

A builder often takes the point of view of doing just barely enough to meet requirements. But, there is no law against doing more than the bare minimum to pass inspection.
 
Lets go off on a little branch circuit here if we can. We have touched on insurance and I was wondering what everyone else does. My understanding from my insurance company is that because I sell a few pieces from my shop they won't carry it under my home owners policy. I'm more of a hobby that pays for itself than a business and thus I can't afford the prices for a business insurance policy. What is everybody else doing?
 
Richard Avram said:
Lets go off on a little branch circuit here if we can. We have touched on insurance and I was wondering what everyone else does. My understanding from my insurance company is that because I sell a few pieces from my shop they won't carry it under my home owners policy. I'm more of a hobby that pays for itself than a business and thus I can't afford the prices for a business insurance policy. What is everybody else doing?
Click to expand...

The AAW has a company that offers policies that provide some coverage through different insurance companies. These are different for every state and will be different depending on how you fill out the for application.

We have a policy that covers loss ( equipment, Materials, inventory, part of the building). and liability for up to 4 classes a year ( because that is what we put in the application ) It runs around $225 a year for what we have.
I have heard reports that some people have not been able to get coverage for teaching classes.

Go to and click business:
http://www.woodturner.org/org/mbrship/insurance/

Depending on state regulations, what you ask for, and which company actually writes the policy there is fair amount if variation.

I suggest you ask for a quote so you know what is available through this route.

We did everything by email.

Al
 
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I don't mean to steal the thread, but since this has turned into a very useful discussion of a variety of wiring question, I have one. When I had an electrician provide a new service panel in my garage to support my 'new' lathe, he wired it with standard NM wire (can't recall the gauge). This surprised me as I assumed 220 required a different type of wire, or more wires within the bundle, or something special. He reassured me it did not. I trust him, but worry I won't be able to keep track of which wires are 220 and which are 110 as I add capacity for other machines.

Does anyone have thoughts on the suitability of standard NM wire, in the proper gauge, for 220v service?
 
Believe your electrician. Most home wiring is done with type NM which stands for non-metallic jacketed wiring. Wire that is put underground and not in a conduit would be type UF (which stands for underground feeder). Permanent wiring that is not in a raceway or inside the stud walls would be one of the jacketed types with metallic or other jacket to protect the insulation from abrasion. There are also non jacketed wires that are used when the wires are protected by being in conduit , EMT or some other type of raceway (in the case of industrial installations).

So, to directly answer your question which really seems to be is type NM "inferior" for that particular application, the answer is "No". I can't imagine what he would have used if not NM. Its insulation is rated to be at least 600 VAC and a temperature rating much higher than anything that would exist in a home.

The following maximum ampacity ratings are listed below for the most common wiring gauges for branch circuits:

  • AWG 14 . . . . . . . 15 Amps
  • AWG 12 . . . . . . . 20 Amps
  • AWG 10 . . . . . . . 30 Amps
  • AWG 8 . . . . . . . 40 Amps
Regarding your concern about needing "more wires", you use the number of wires in a jacket that is needed for whatever you are running a branch circuit for. An oven, range, or clothes dryer normally needs 4 wires -- the two high legs, neutral, and ground. The reason for needing neutral is that those appliance typically have something that needs 120 VAC such as lights and the control panels. Ground is needed for anything with a metal frame to provide safety against electrical shock.

A woodturning lathe that requires 240 VAC normally has three wires -- the two high legs and the bare ground wire that connects to the frame of the lathe. I have a four wire service to my lathe, because it also has lighting. This means that I also have neutral in addition to the other three.
 
Richard Avram said:
Lets go off on a little branch circuit here if we can. We have touched on insurance and I was wondering what everyone else does. My understanding from my insurance company is that because I sell a few pieces from my shop they won't carry it under my home owners policy. I'm more of a hobby that pays for itself than a business and thus I can't afford the prices for a business insurance policy. What is everybody else doing?
Click to expand...

Does your business file a tax return?
 
Not even a debate, run a separate 20A 220 volt circuit .

Mike Kratky
Licensed Master electrician(40 years)
NY State Electrical Fire Underwriter Inspector (20 Years)
 
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