# 220v 15 amp plug to 30 or 50 amp socket



## Paul Wheaton (May 10, 2002)

So I finally bought a skillmill saw mill thinking that I could have a little side business converting the logs of city folk into lumber. The great thing is that since it is electric and draws a humble 12.5 amps, I could just pull up at somebody's house, plug into the nearest 110 outlet and I'm in business!

It arrived and ... @#$%^&*! That plug ain't right!

A little research .... This plug is a "NEMA 6-15P": 220 volts and 15 amps. 

Okay ... when I get to somebody's house, I'm gonna hafta tap into their range or dryer power ... I'll just pop over to the hardware shop and get the stuff to make my 15 amp needs tap into the 30 amp or 50 amp receptacles. 

I'm trying to wire it up and .... it looks like the 30 and 50 amp 3-prong plugs have no ground and instead have two hots and a neutral. The 15 amp female is a hot, a neutral and a ground. This ain't a gonna mix ....

This is starting to get really complicated. I suppose I could take the neutral and a hot and then put in some kind of grounding rod ... but at this point I'm not sure if that will work, or if that's the right kind of fix.

Help!?


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## ace admirer (Oct 5, 2005)

most old 220 applications did not have a ground wire,,,just as old houses did not have a ground wire at outlets...the new nec requires a four pronged plug (with the ground wire)


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## crafty2002 (Aug 23, 2006)

Paul, I will probably get flamed for telling you this but I will anyway. 
My BIL started teaching me electrical work when I was a kid, well, I guess about 1964 and I have worked as an electrician a bunch of times. Sometimes I would be hired on as a welder and one of the foremans knew me and would swap me over to the electrical department. Sometimes the other way around. I liked it that way. Change of pace and still on the same job and still top pay. That's what matter was top pay. 
It hasn't been that many years ago since the idea of a ground came out. They did without it for somewhere around a hundred years.

Codes are partly made up with the suggestions from companies that build or make things for the public, and as we all know, will add anything that will make another dime on a product.
You have a 4-wire cable coming from the saw. 
Two of which are 120 volt lines coming from the separate buss bars in the breaker box. One goes to the neutral bar. And one goes to the ground bar.
The funny thing I never figured out and no one has ever been able to explain to me is why the ground and the neutral bars are tied together in the breaker box. 
There is a ground bar on the right side of the box and then the neutral bar on the left side and a bar that ties the two together that runs just above the main breakers. 

"THIS IS NOT BY CODE" but you can tie the neutral and ground together at the plug and get the same thing you get running 4 wires. 
What difference does it matter if there is 100 feet of wire separating the neutral and ground if they go to the same place in the end. 

Some will argue that the feed back will be greater and I will say to start with, I think this is bull s$%$ run up by companies for extra profit. 

I will also say that you could very well drive a grounding bar in the ground beside the plug to tie into but it sure seems like a lot of work for nothing. 

I have a 200 foot roll of #10-3 pump wire I use for the welder and did use for the compressor before it walked off. I wired it into a 4 gang plastic box with two types of 240 volt and two 120 volt receptacles, and I use the ground for the neutral and ground hook up on all of them. It hasn't killed me yet. Highly doubt it will. 

So who ever thinks I am telling him wrong, this is my opinion with better than 40 years fooling with electrical.

Another bit of info that might help you out. On the plug end of the wire, you can tie two or more plugs to the same wire. I have two on mine so I can plug it into two different types of receptacles and have two worn out receptacles that I have run the rubber pump tape around to keep the extra plug from being exposed and I just pick out the one I need and plug the extra plug into it and then plug the correct one into the dryer or cook stove outlet. 
I made it when I was sanding floors to start with and it just grew. :bouncy:

I hope you see where I am coming from. If not PM me and I will give you my number so you can call. 

Good luck
Dennis

PS. Congratulations on the saw mill. Hope it does well for you.


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## tyusclan (Jan 1, 2005)

Paul Wheaton said:


> I'm trying to wire it up and .... it looks like the 30 and 50 amp 3-prong plugs have no ground and instead have two hots and a neutral. The 15 amp female is a hot, a neutral and a ground. This ain't a gonna mix ....


First of all, those are not two hots and an neutral, it's two hots and a *ground* and *yes*, there is a BIG difference.

I don't mean this to be personal, but please ignore everything crafty2002 said. That is not only dangerous but illegal. 

Yes, the ground is tied to the neutral *in the box*, but they have two *completely* different functions, and they should *never* be tied together anywhere else. The neutral should *always* be an insulated white wire. This wire is to complete the circuit to the panel, and carries voltage. The ground wire can be bare or green and is *only* to carry voltage to the ground rod in the event of a short.

There is no easy way to correctly do what you need to do. The manufacturer put 4 wires in the cord for a reason, and they all have their function. Are there short cuts that will work? Absolutely. But you're asking for trouble if you try to do it.

Also, if you do find a 4-wire 30- or 50-amp plug to tap into, you need to fuse it to 15 amps before you plug your machine into it.


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## Paul Wheaton (May 10, 2002)

crafty2002,

I admit that that is a bit wacky. It seems I read in a book somewhere what the reason was, but now I cannot remember it. Gonna hafta look that up.

tyusclan,

Please help me to understand the need for the 15 amp fuse.

Also ... supposing there is a four prong outlet ... My saw has three prongs: hot, neutral and ground. Would it easily map to a four prong outlet using just one of the two hots?


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## idahodave (Jan 20, 2005)

The neutral wire is the path that current takes that's operating the load. 

The ground wire is for safety. It stops you from being shocked (or killed) if there is a short from the hot wire to the equipment frame.

The neutral is connected to ground at the service entrance panel. This is done so there is a path for static, leakage, or lightning currents to ground on the power line. The connection also keeps the neutral and ground systems in your house at nearly the same potential. 

The neutral and ground are separate lines to the equipment because they have different purposes.

The fuse (or breaker) is needed to protect the wiring and motor from a 30 amp circuit. The saw is rated at less than 30 amps according to the plug.

Everthing will work with 3 wires until something goes wrong. Then it could put your life, or others, at risk.


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## morrowsmowers (Jun 14, 2004)

There are adapters made for motor homes to connect (I believe) 30 amp homes to 50 amp outlets. There may be something like this, premade, that you could use.

The information you have received about the ground and neutral being kept separate is also correct. Ground is for safety, neutral carries current.

My dryer is on a four wire system that has 2 hots and 2 grounds. One ground is wired directly to the motor while the other is tied to the chassis. They say that this is to isolate the user from shocks should the motor or an element short. You will need to be sure which way your connections are wired.

Ken in Glassboro, NJ


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## tyusclan (Jan 1, 2005)

Paul Wheaton said:


> tyusclan,
> 
> Please help me to understand the need for the 15 amp fuse.
> 
> Also ... supposing there is a four prong outlet ... My saw has three prongs: hot, neutral and ground. Would it easily map to a four prong outlet using just one of the two hots?


Okay, I thought you had said that your saw had four prongs. I misread that part.

If your saw only has three prongs you only need two hots and a ground. If they have a three prong receptacle you'll be fine. You can tap into their receptacle. If they have a four prong, you can still use it. You would just need to tap the two hots and the ground again, ignoring the neutral. You would need to keep an adapter for each, depending on which one each customer has.

The purpose of the fuses is to protect you and your saw. If the saw is rated for 15 amps and there is a short in the saw, the saw or the cord could catch fire before the larger breaker tripped. A 15 amp fuse in the line would trip before the saw or cord caught fire.


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## tyusclan (Jan 1, 2005)

morrowsmowers said:


> My dryer is on a four wire system that has 2 hots and 2 grounds.


Not to nitpick, but this in incorrect. You have two hots, *one neutral*, and *one ground*.

The neutral is tied to the motor, and the ground is tied to the chassis.


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## Paul Wheaton (May 10, 2002)

I now understand the difference between neutral and ground. Makes sense. Thanks fellas!

Now, taking a look at my plug, it is a "nema 6-15p": my reading suggests that this is 220 volts, 15amps, one ground, one hot, one neutral. 

tyusclan,

you said that I need to map two hots and a ground to that. Either you're thinking of a different plug, or else my understanding of a "nema 6-15p" is wrong. 

Based on what you all have taught me so far, my thinking is that I should rig up some sort of portable breaker box that has a nema 6-15r receptacle on it. And then it has an 8 foot cable coming out of it that might be, say, a 50 amp line. Then make converters between that and any other receptacle. If I encounter something that has only three prongs, I need to also have a ground line that goes to a grounding rod that I drive into the ground outside.

It sounds like any shortcuts around this would only lead to possible hazzards - plus possible damage to the motor on my sawmill.

Am I on the right track now?


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## Paul Wheaton (May 10, 2002)

Take a look at the A220-15D on this page: http://quick220.com/220_catalog.htm

First, that's the kind of socket for the plug I have on the sawmill. 

Second, this contraption sounds like just the ticket: anybody think this is a less-than-optimal solution?


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## idahodave (Jan 20, 2005)

I jumped to the same conclusion...that is you had a four wire plug.

The flat blades get connected to opposite sides of the line, both are hot. If one was neutral you would have 120v not 240v. The round pin gets connected to ground.

This is the same as a three wire dryer outlet. Two hots and a ground.

New houses have a four wire dryer outlet, two hots, neutral and ground.

You will need to have two adapters, one with a three wire plug and another with a 4 wire plug. Don't connect to the neutral on the four wire.

The adapters will need to include the 15 amp protection for the saw. A GFI would also make a nice addition.


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## idahodave (Jan 20, 2005)

I looked at the converter, and trying to do this was my first thought. 

It does need to have two 120v outlets on opposite sides of the line to work. You might have to search around to find them but it should work OK.


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## tyusclan (Jan 1, 2005)

Paul Wheaton said:


> Now, taking a look at my plug, it is a "nema 6-15p": my reading suggests that this is 220 volts, 15amps, one ground, one hot, one neutral.
> 
> tyusclan,
> 
> ...


If it's 220 volts with 3 prongs, you will not have a neutral. You will only have two hots and a ground. If it were 120 the 3 prongs would be one hot, one neutral, and one ground.

If it is indeed a 3-prong, 220 volt, you would not need to drive a ground rod. The ground prong on your plug will ground the saw.

Instead of just looking at the NEMA number on your plug, check the data plate on your saw, and make sure what the voltage is supposed to be. That's the voltage you want to supply to the saw.

A small fused disconnect with a cable and end to fit a 3-prong dryer receptacle would be a good idea. You could probably get an adapter that would plug into a 4-prong, and you could then plug your 3-prong into that.


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## Paul Wheaton (May 10, 2002)

Is it possible to get the two hots in the wrong order? I would guess that it doesn't matter.

So I can go ahead and make adapters then? All I would need to do is to map the two hots and the ground on all adapters - ignore the neutral if there is one - yes?



> The adapters will need to include the 15 amp protection for the saw. A GFI would also make a nice addition.


Also? Are thinking there would be two layers of protection?

From the mill motor plate:

2.2 KW
220 V
12.5 A
"Ins F"

There was more, but I didn't think there was much value.


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## agmantoo (May 23, 2003)

I would hard wire the 3 prong plug to the saw pigtail. Then obtain a Male 4 prong and a female 3 prong receptacle and make a second short jumper cord with these parts and connect only the 2 hots and the ground of the female to the same points in the male 4 prong plug. When at a customer with a 3 prong receptacle do not use the second jumper. When needing to connect to a 4 prong receptacle use the second short jumper cord in series with the first cord. I would use 10 gauge wire in the cords knowing that the plug and receptacle are undersize but aware that the rest of the circuit from the saw to the house is adequate. At the saw I would install a two pole circuit breaker with box to accept the feed wire from the house.


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## tyusclan (Jan 1, 2005)

Paul Wheaton said:


> Is it possible to get the two hots in the wrong order? I would guess that it doesn't matter.



It will not matter in your application. The only time the order of the hots makes any difference is in three-phase applications. In that case you have 3 hots, and changing the position of any two will change the direction of the motor.

Your saw is single-phase, so the position of the hots makes no difference.


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## idahodave (Jan 20, 2005)

The GFI adds another layer of protection for the operator.

NEC doesn't require one for most 240 v circuits. OSHA would require a GFI for outdoor equipment power. 

Many don't like nuisance trips that plague some applications and a 240v GFI is expensive, but if you plan to hire a helper it would be a good thing to have.


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## morrowsmowers (Jun 14, 2004)

tyusclan said:


> Not to nitpick, but this in incorrect. You have two hots, *one neutral*, and *one ground*.
> 
> The neutral is tied to the motor, and the ground is tied to the chassis.


You are correct that it does connect to the neutral bus in the circuit panel. It, however, does not carry and motor current so it is not a true neutral. A neutral carries current. The schematic on the dryer shows it as a ground. The motor and elements are all running on 240 volt (2 hots, no neutral) and that wire only carries current if something malfunctions. In that case, that connection will become hot and would cause the breaker to trip. The actual ground is running from the chassis and cabinet of the dryer only and ties to the ground bus in the panel. The reasoning for this is that if the dryer were to short out at the same time someone was touching the cabinet, especially in a potentially wet environment like a laundry area, the current could pass through the person causing possible electrocution. By separating those lines, you have protection on the dryers electrical system without risking human life. IF that were a true neutral, the dryer would be running on 2 - 120 volt circuits and not on 240 volts. That is why, also, when I bought the dryer, I had to detach the connection from the cabinet to the motor ground (neutral) to make it a 4 wire connection. If I were using 3 wire, the connection from the motor would be connected to the cabinet and also to the ground at the panel. The other 2 wires are your 240 volt hot legs. With 3 wire the dryer works properly and has no neutral. The same dryer, connected to a 4 wire system, will also work properly and the voltage doesn't change. It is using the neutral wiring as a second ground leg.

Ken in Glassboro, NJ


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## tyusclan (Jan 1, 2005)

A four-wire cable will contain one red, one black, one white, and one green (or bare). The white is generally used as a neutral on appliances that requires 120 volts for some reason, such as a clock. 

It may well be that your dryer uses that white wire as an alternate ground for the motor and the green to ground the chassis. Some local codes will not allow this. They require the motor and chassis to be grounded together on the ground wire.

When you said that you had a 4-wire plug on your appliance I assumed that the white was a neutral. 

We all know what happens when we assume. 

Sorry.


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## rambler (Jan 20, 2004)

Paul Wheaton said:


> Also ... supposing there is a four prong outlet ... My saw has three prongs: hot, neutral and ground. Would it easily map to a four prong outlet using just one of the two hots?


Paul, 220 in the USA always needs to have 2 hot wires - each is 120v on a different cycle, so together they make 240v.

So, you are mis-lableing your wires somehow. A 240v appliance does not need a neutral wire. That is _only_ for 120v items. If your item does not have any 120v light, timer, or so on it, it would not have a nuetral.

The ground is there to protect you from death or the wires or item from dmaaging themselves. Hopefully you never actually use the ground wire even in your life, and that would be good. So as Crafty says, you can wire that up any old way & you won't ever know you got it wrong - unless you actually needed it. Since you are going to other people's property, you decide how your insureance & concence feels about that.

I too was assuming you had a 4 wire plug, 2 hots to make 240v; a neutral to use with one of the hots to make 120; and an isolated ground wire to be used if something goes wrong.

You can't get 240v out of a hot, a neutral, and a ground.

What do you really have?

--->Paul


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