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no neutral, 220v 3wire. can i get 110v?

ksoggs

Plastic
Joined
Dec 4, 2010
Location
cleveland ohio
I only have a 3 wire outlet by my mill... hot hot ground... no neutral.
But i have a few devices that want 110v power, primarily my 24v power supply to controll my contactors and relays for my phase converter.... my choices are....

1. run a seperate 110v wire to the mill as well to power the 110v items.

2. use the ground as neutral, and power the 110v items between L1 and ground. (old school before they had neutral and ground)

3. run the 110v items in 220v mode (european mode) and then wire them with the hot hot ground just like other 220v things. i assume this would work, but never played around with the 110/220v switch on things like that... but i dont know if europe gets its 220v on a single hot, and still has a neurtal and ground... or if it uses 2 hots and a ground like we do... that is what i am curious about.... or if it even maters.
 
I know but don't answer questions about DIY electrical work unless at the scene. If you have to ask you really need an electritian..they can lead to longer life.
 
"European" 220V power is not the same as what you wire up in the US as 220V because it operates at a different Hertz. The US is on 60Hz.; and Europe uses 50Hz. That's the only practical difference. Of course that matters... but based on your question, I expect all of your equipment is rated at 60Hz?

DO NOT USE GROUND AS NEUTRAL. Neutral is connected to things such as your conduit or light switch box. Using your Ground as Neutral can be dangerous for this reason. Suddenly you touch something and that power goes to you instead of the "ground"... meaning the actual earth, the dirt.

The easiest course of action would seem to be to change the leads on your equipment if it is dual rated 110/220V. Done. Stay with 220V for everything. Failing that, you can buy a transformer that will take 220V and step it down to 120V. They are not terribly expensive. Surely less than the cost of running a new breaker and line from your main box.

Lastly, as you say you have two live wires and one neutral, I am working on the assumption that you are wiring up single phase devices (sounds like you're wiring a phase converter for the mill?)
 
You can use a 2:1 transformer to make 220 into 110 locally on the mill, then ground one leg of the 110 to create your own locally derived neutral. I did this recently on my Aciera F4 to provide power for the lamp and DRO. I fused the transformer inputs and outputs appropriate to the wire size and kVA rating of the transformer. Little control transformers are cheap on eBay.
 
If there's 3 wires going into your shop area (neutral, two hot legs) then you can probably drag the neutral over to your 220 outlet and make a legit 110 out of it. Especially likely if you have any 110 in the shop. But if you don't know what you're doing, get an electrician. For example, you'll want to make sure the breaker setup plays well with such an arrangement.
 
If there's 3 wires going into your shop area (neutral, two hot legs) then you can probably drag the neutral over to your 220 outlet and make a legit 110 out of it. Especially likely if you have any 110 in the shop. But if you don't know what you're doing, get an electrician. For example, you'll want to make sure the breaker setup plays well with such an arrangement.
But his 3rd wire is not a Neutral, it's a Ground.
 
Bottom line, it's illegal (well,against the National Electric Code anyway) to use the Ground conductor as a Neutral, even though technically they are at the same potential. In other words it will work, but it's not permitted.

So if you do it anyway and something catches fire and an insurance inspector sees it, they can use it as an excuse to get out of paying.

Go with the suggestions for adding a dedicated transformer, that's the officially sanctioned way to deal with it.
 
The ground conductor cannot be used as a neutral because it is usually bare, without a thermal/electric rated insulation. In a Romex wire, you have 3 insulated conductors and 1 bare conductor. Obviously if it is insulated properly, there would be no foul there.

As mentioned above, the way machine tools usually do it is they use a step down isolation transformer so the potential of your 2 legs to make 240V become 2 legs to make 120V. This is also how many machines deal with the delta high leg issue. High leg is only a problem when it is referenced to neutral. leg to leg, it is just fine.

Bottom line, I still don't even know what you are really trying to do but the distance, ease of rewiring, etc would all dictate which route you take. If you truly need 120V, either set a properly sized isolation transformer or just pull another load carrying conductor for the neutral OR if the ground that is there now is properly insulated for a load conductor, make it the neutral and get some bare copper to pull for the ground.

By code, rigid conduit can and is used as the ground in commercial apps. Supposed you could also install conduit instead of pulling wire. As you can see, several ways to skin the cat but using a ground as a neutral is a no-no.
 
conduit ground

I only have a 3 wire outlet by my mill... hot hot ground... no neutral.
2. use the ground as neutral, and power the 110v items between L1 and ground. (old school before they had neutral and ground)
Are you sure the third wire is ground and not neutral? You can only determine that by tracing the wire back to the service panel and determine where it's connected.

Code requires separate neutral and ground conductors. HOWEVER, the ground can be accomplished through conduit (EMT), which would free your conductor for use as a neutral.

- Leigh
 
Code requires separate neutral and ground conductors. HOWEVER, the ground can be accomplished through conduit (EMT), which would free your conductor for use as a neutral.

- Leigh

This is worth noting...... But if the wire is green, or bare, the questions are over with.....

Use a transformer, it is the right way, no questions.... power and control operate off the same wires, so disconnection of one is disconnection of both. Otherwise, it might be possible for the machine to stay energized even if one power wire opens.... so long as it isn't the one running the machine controls (if they run from 110). With a transformer, if power drops, the controls open and the machine won't re-start.
 
Boy JST, maybe you read more into this than me but all I got was , "i got some stuff to run".

If indeed the OP is trying to connect a machine, I firmly agree that you need to run only one service to the machine and use transformers for reduced power needs so everything will disconnect at once. Much safer and smarter.

"green is ground", JST, you must not get into residential rewire much... I have learned to never trust a damn thing. Hell, isn't black ground, just like on my car??? really, that is kind of stupid. Why can't we have more universal colors..



EDIT: oh, ok, maybe a DIY control box for a phase converter??? For that stuff I just carry the neutral over and use a leg of power for 120V loads. I see reason for any 24V loads in something like that. Oh, it should be worth noting that I use a fuse on reduce gauge wire inside the cabinet to properly protect the wiring to the 120V loads. This way I do not need any separate 120V power. If you do not fuse the 120V loads, you are creating a hazard because those smaller wires and devices are otherwise not properly protected.
 
Boy JST, maybe you read more into this than me but all I got was , "i got some stuff to run".

Just

But i have a few devices that want 110v power, primarily my 24v power supply to controll my contactors and relays for my phase converter

Sounds like machine controls to me.

"green is ground", JST, you must not get into residential rewire much... I have learned to never trust a damn thing.

I've seen quite a bit, but no, I don't do that..... I had enough of it at my house..... 14 ga Aluminum wire clear across the house to an outlet in dining room..... tapped into a circuit protected at 40A (dryer outlet) :eek: :willy_nilly:......... lights and ceiling fans wired-in by twisting the wires around the wires in the box, and wrapping the twisted wires with scotch tape (I am not kidding) :crazy::skep::nutter:.

None-the-less, green (or green with yellow tracer) is supposed to be ground, and if it isn't, then some wire-pulling may have to be done, or the existing conductors re-wired properly per colors.
 
Great thread guys. Thanks for clearly explaining the safe ways of getting this done for when the machine has a requirement for 110V or even 24V and all you have coming in is 220V. Much appretiated :D

Will
 
no neutral, 220v 3wire. can i get 110v?

The outlet your refering to is a polarity sensitive australasian outlet, 240 volts, it has an active neutral and earth.

Any modern day outlet will have these 3 components and be polarity sensitive. Yes you can put active and neutral into a 2:1 transformer and 240 volts becomes 120 volts.

The low voltage appliances you are powering generally feature a regionalised "kettle" cord that power a switchmode transformer they don't care if you give them 120 volts or 240 volts or 50 hertz or 60 hertz. Moving to another country usually means changing that regionalised "kettle" cord or to buy a new inexpensive switchmode adapter for that item.
 
The outlet your refering to is a polarity sensitive australasian outlet, 240 volts, it has an active neutral and earth.

Any modern day outlet will have these 3 components and be polarity sensitive. Yes you can put active and neutral into a 2:1 transformer and 240 volts becomes 120 volts.

The low voltage appliances you are powering generally feature a regionalised "kettle" cord that power a switchmode transformer they don't care if you give them 120 volts or 240 volts or 50 hertz or 60 hertz. Moving to another country usually means changing that regionalised "kettle" cord or to buy a new inexpensive switchmode adapter for that item.

A) Nechromancer. This is 10 years old thread :D
B) What the *** australasian outlet has to do with Cleveland, Ohio, United States of America?
 
Are you sure the third wire is ground and not neutral? You can only determine that by tracing the wire back to the service panel and determine where it's connected.
- Leigh

Untrue. At the service entrance the ground ING and ground ED conductors are bonded. They all terminate at the same potential,
at the same terminal strip(s).
 
Untrue. At the service entrance the ground ING and ground ED conductors are bonded. They all terminate at the same potential,at the same terminal strip(s).

For the service panel, this is correct. For a sub-panel they are separated. An insulated neutral bar has been the requirement for more than a decade now. Garage shop panels are often sub-panels.

SAF Ω
 








 
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