Need Help!- 3 wire 220v, no neutral, can i use 110v?

[Ksoggs]

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.

[UUU]

In the UK we have single hot, neutral and ground.

In reality the neutral is a bit of a fake - the main power distribution is three hot phases at 120 degrees to each other. Commercial power is all three phases, domestic just gets one phase with roughly one-third of the houses connected to each phase to even things out. If they get the balance right then the current down all the neutrals will balance out.

[Al_The_Man]

I have never heard of using ground as neutral, legitimately that is.
It is certainly againts the code to use it at present.
You cannot ground one side of the 240 as is done in Europe and elsewhere, it will blow a fuse right away.
They use 240v only system, which does not use a centre tap grounded neutral so they are able to ground one side of the 240v and make this neutral.
The star point of a 3 phase supply is the neutral in this case.
You basically have two choices, run a neutral or set up a local 120v supply using a 240v/120v transformer.
Another is to obtain a switching supply, most have a range of 90v-240v AC input.
Al.

[mcphill]

Can you grab a neutral from a nearby 110 outlet and run just that over? I ran 4-wire 220 to my outlets for just this reason. I have a hot-neutral-ground combo to power 110 boxes on the machine, with hot-hot-ground running the 220 stuff.

[67barracuda]

You could share the neutral (white wire) with either the red or black from your none neutral 220 circuit and have it work. The problem being is that the neutral wire is not protected by a breaker so multipile loads at the same time may not trip their own breakers but could overload the neutral leading to a fire hazard.

[cheetahcnc]

Only with a transformer.

Jim

[Al_The_Man]

Originally Posted by 67barracuda The problem being is that the neutral wire is not protected by a breaker so multipile loads at the same time may not trip their own breakers but could overload the neutral leading to a fire hazard.

Don't forget each opposing hot leg is 180° out of phase with each other, so conversely the neutral will be 180° of of phase with each hot conductor.
The load would be additive in the neutral if the hot conductors were in phase with each other and 180° to the neutral.
Al.