220 V wiring of multiple pieces of machinery

[Avadon]

Anyone know if there is a gadget or a trick for running several 220V pieces of machinery on the same line. Do they make like a selector switch for this? I know if you got compressor on one side of the shop and your welding on the other chances are they need their own line. But if you have a compressor with a 220v sander near it, it seems like there would be a better way then running endless 220V lines for each piece of equipment. What do they do in big shops where they have dozens of 220v machines? Do they really use a dedicated line for each? Is that best? Or is there a simpler way for the home shop?

[Tormented Soul]

I would check with your local code first.
All 220V machines in my home shop are on their own circuit with a properly sized breaker
and or point of use fuze.
Most all industrial wiring that I have seen has been done that way except for
a few plants that I've been in that had "buss bars" hung from the ceiling.
Even then each machine hooked to the "buss bar" was properly fused.

Hope this helps.

Zach

[Steve Sells]

Good point about checking with local building Dept.
Buss bars are set when we have to deal with a lot of power, for many things. But still as you pointed out, each machine has its own line, because the disconnects that are on the buss are all fused. We do not do multi-taps for machines. Dont try to get cheap with the electrical, its asking for fires. Hire an electrician.

[Avadon]

Not looking to "get cheap," simply looking for the most practical way to do it.

[Bryce Masuk]

they would run a main to a breaker and run the individual machines of smaller lines coming to a specific breaker for each line.

you could also run a main to 3 boxes and put a plug on each piece of equipment if it supports it, or you could also simply use a lighter line and only run things at specific times, say your welding your probley not also running the belt sander at load both at once or you would have to be smart and not let the compressor flip on at the same time as welding, having the machine on isnt a big deal but drawing a load is a different story.

or you would provide enough power to run everything you will have to figure all that out depending on how much you want to spend and how perment its going to be, if you wanted to add a fuse to the box and run something off that it might be cheaper than running a new main off the meter and then a new breaker box.

depends on what you need if you need more than 50 amps you probley need to spring for the whole system if you can run off 30 amp you might be able to use a 220 volt extension cord

[pkrankow]

There are specific rules for running dryers together for a laundromat but I am not aware of for other equipment. Unplugging and then plugging something else in is an option for some things at least.

Phil

[Nakedanvil - Grant Sarver]

You're asking for advice on how to do something wrong. You "should" have a separate circuit for each machine. I don't always, but I do it in the full knowledge of the perils. If you run a circuit for two machines, the wiring needs be sized to handle the load AND you need proper overload protection on each machine. Sometimes, like with the compressor and sander both machines might be running at the same time. I have two large belt grinders on one circuit, but I never run them both at the same time. People here should only tell you the right way. Anything else, you're on your own.

[Steve Sells]

I define cheap as trying to do it yourself when you don't know, rather than hire or at least ask a professional , whos career is electrical. Which you may not realize this but you did anyway, but will you listen?

[Avadon]

I'll just put them all on separate lines then. I just thought there was something like a bank of plugs attached to an A, B, C, D style dial selector so your only running one machine at a time but you can just select over to another machine. This way you wouldn't be running three 220 lines over to one side of a shop where you only ever use one machine at a time. For example you wouldn't use a drill press, sander, or power hammer, etc. at the same time if your just one person in a shop. Compressor was probably not a good example as that IS something that should really be on it's own line so you can let it kick on whenever it's low.

Thanks

[Steve Sells]

There is a switch for these things, its the same one we use for switching between overhead lines, and a generator, that are hundreds of dollars for the amperage you need... it is usually cheaper to runs separate lines.

Get a written estimate from a licensed Electrician. No good sparky will charge for an estimate. Ask them how best to do what YOU want to have as an end result. When you got 3, you not only have 3 opinions of how they think its best and safest, but you got 3 prices. it may not be as much as you may fear, and if they do it, they have insurance to cover things too.

[petere76]

Avadon,

Running amps are not the issue on most circuits.Rather its the starting amps that cause the current spikes. Motors like on pumps and compressors have large demand on startinijg ( across the line) and relatively little demand while running. The compresssor will be the most problematic because it start and stops as the pressure fluctuates.

Breakers and fuses. Fuses protect the motor from oveload and breakers protect the line (wiring bus bar etc) from overloading and subsequently failing. The breakers are the big number to keep an eye on because the wiring is buried in the walls and races. Most motor fusing or thermals are either in the local controller ( 3 phase) or in the case of small (single phase cap start units) motors, they are internal heater elements (small reset buttom). The heater cools off and you can reset the motor. Important ... If its running hot find out why, not paying attention here can come back and cause big problems.

When wiring circuits make certain that you use the recomendeed AWG size wiring or larger for any given circuit ( motors starting amp rating) . Always use the right size or go one size larger. This is the easy way to prevent problems.

When you run multiple motors on a single circuit you have to calculate the "across the line" starting amp draw down otherwise you will keep tripping the line circuit breaker. Also remember that when circuits are in use they (cables) warm up and the resulting temp rise causes the resistance in the cabling to increase which also degrades the current carrying capacity. The easy answer in this scenario is to simply increase the wire size on the run, Your local codes may require seperate branch circuits for each individual device, Be guided accordingly. Be safe,,,not sorry.

Peter

[Nakedanvil - Grant Sarver]

Avadon,

Running amps are not the issue on most circuits.Rather its the starting amps that cause the current spikes. Motors like on pumps and compressors have large demand on startinijg ( across the line) and relatively little demand while running. The compresssor will be the most problematic because it start and stops as the pressure fluctuates.

Circuits are designed for the run load, usually 120%. Plus the rated ampacity of wire is only 50-70% of what it can actually carry. The high inrush by occasional starting is not a problem.

Breakers and fuses. Fuses protect the motor from oveload and breakers protect the line (wiring bus bar etc) from overloading and subsequently failing. The breakers are the big number to keep an eye on because the wiring is buried in the walls and races. Most motor fusing or thermals are either in the local controller ( 3 phase) or in the case of small (single phase cap start units) motors, they are internal heater elements (small reset buttom). The heater cools off and you can reset the motor. Important ... If its running hot find out why, not paying attention here can come back and cause big problems.

Peter

Fuses and breakers are both over-current devices. Breakers have the advantage tripping all legs to the motor. Fuses are poor protection for motors as they can possibly drop one leg and leave the others live. A three phase can keep running in that case. Motor protection is only supplied by a proper motor contactor. This also drops all legs when one of the heaters trip. Magnetic contactors also have the advantage of not restarting after a power loss.

[Steve Sells]

We bark a lot, but it's because we care. If we didn't care, it would be much easier to ignore a post.

[Mainely,Bob]

We bark a lot, but it's because we care. If we didn't care, it would be much easier to ignore a post.

Well said Steve.

[Spears]

Good news is, if you bite the bullet and run a separate line on its own breaker, your property value stays high. Nobody freaks out when they see something that "they" think is "rigged". If your going to die there, it matters less on what the next guy thinks. But if you ever decide to relocate, wouldn't it be better not to hear the words "who in the hell did that?". Stay safe and keep your shop to the highest reputable standard available. Judge you they will! Sincerely, Spears.

[ThomasPowers]

Having bought my first house from a widow with small kids whose late husband, a maintenance man with the phone company, had managed to electrocute himself working in his house, I would like to advise you towards SAFETY!

Now would running a 220 sub panel that you could then break out into separate 220 runs in the shop work better for you? It's nice to have the breaker box close to the machines anyway!

[Avadon]

This is actually all I was asking about lol found them on digikey and there are probably others on msc now that I think of it.

Turns out they do make something like this.. whether or not these will work specifically for what I'm doing needs some investigation.

3 position selector switch

2 position selector switch

[Steve Sells]

that is for a DIN rail system, and this is my last post on this dead horse. good luck

[petere76]

Avadon,

I leave you with the experts. Good luck with your project.

Peter

[Nakedanvil - Grant Sarver]

Both of those are identified as "disconnect switches". They only have three wires going in and three going out. I don't see how they could do what you want.

[Fosterob]

Those are simply on off switches. The easy and cheap way for you is to run a circuit to everyplace you want an outlet. If you do not want to spend money on duplicate breakers and outlets then just put as many outlets as you have machines of similar load. All 20 amp machines plug-unplug into their own outlet maybe the other wall has 30 amp eqiup on it. etc etc. Best is a separate circuit for each machine with its own properly sized breaker.
Rob

[Steve Sells]

Those are simply on off switches. The easy and cheap way for you is to run a circuit to everyplace you want an outlet. If you do not want to spend money on duplicate breakers and outlets then just put as many outlets as you have machines of similar load. All 20 amp machines plug-unplug into their own outlet maybe the other wall has 30 amp eqiup on it. etc etc. Best is a separate circuit for each machine with its own properly sized breaker.
Rob

The problem is that is Illegal, you may not just put as many as you wish on a line. I don't know where you got your license, but its hard to believe you still have it doing dangerous things like that.

[Fosterob]

Steve I think you misunderstood what I was trying to say. Run one outlet for a group of machines all that have similar power requirements and have them plug into the outlet one at a time depending on which machine you choose to use. That way you are not using a 50 A breaker to protect a 15A machine. Each machine is plugged in as needed just like if you were to use your dryer outlet.
Hope this helps to make it clear that I was not saying to hardwire multiple machines on a single breaker.
Rob

[Steve Sells]

Thank God I mis-understood you, Thank you for being more clear. It gets scary when you have seen the things I have to repair.... mostly work done by people that think they can do what they want to...

For the record: the breakers in a panel or disconnect, are not to protect the machines, it is for protecting the wiring. If/when a machine needs overload protecting they have "heaters" (like small fuses or even a type of breaker) in or on the machine itself.

[Fosterob]

Steve, Thanks for the info on breakers to only protect wiring. Now that I think about it each piece of my motorized equipment has its own overload protection. I am just so accustomed to pluging in the end of the cord that I forget about the overload protection on them.
Rob