110v Light Wiring On 220v 3phase Lathe?

[KenH]

Maybe I'm missing something here, but why not just take an LED light similar to what I linked to above and connect right across two of the 220vac legs so when lathe is turned on, the light comes on? I don't mean "turned on" to spinning, but when power turned on to the lathe.

OR - would that be bad per NEC?

Ken H>

 

[nightowl499]

I had the same thing to do but decided to opt out and run a seperate 110 line for the light
added a quad box so i can also run my pump light and dro when it comes from the seperate
quad, plus i didnt want to lose one side of my 220 over a light or sumthing shorting out . easy to just
run and have the extra plug ins

 

[bbutcher]

I searched and didn't find a similar thread. I don't intend to duplicate.

I'm wiring a 220v 3ph lathe, and would like to wire in a 110v machine light without stretching any copper not needed.
Is it correct that I should be able to connect 1leg of the 110v light to one leg of the 220v wires, after I ensure that it is not the leg off the RPC?
However, the second leg would require additional copper wired normally to the panel, because wiring to the ground seems like a bad idea.

Is this accurate?
Are there better/different/safer options?

Thanks,
Daryl
MN[/QUOTE

With "real" 3 phase power the voltage usually is 208 Volts rather than 220 Volts, but often it is called 220, and the difference is trivial. In that case the voltage measured between any two of the three hot wires will be 208 Volts, and the voltage from any hot wire to ground or common in a 5 wire system, will measure 120 Volts (maybe 117). Both the ground and common (neutral) wires are attached together and to a metal rod driven into the earth at the breaker panel where power comes into the building so they are electrically the same thing. Due to resistance in any wire, if there is a current flowing in the wire, there will be a voltage produced due to Ohms law V = I*R, and ideally any wire carrying a current should be attached to the common (also called neutral) wire which then may have a small voltage above ground due to the current and resistance. In an ideal world, the ground wire will not have any current flowing in it, and therefore will not have a voltage difference measured to the earth ground. Pulling a small current from a lamp will have negligible effect on this.

The lamp therefore can be wired between any one of the three hot wires on the RPC and neutral or ground and should work just fine.

 

[DForeman]

I searched and didn't find a similar thread. I don't intend to duplicate.

I'm wiring a 220v 3ph lathe, and would like to wire in a 110v machine light without stretching any copper not needed.
Is it correct that I should be able to connect 1leg of the 110v light to one leg of the 220v wires, after I ensure that it is not the leg off the RPC?
However, the second leg would require additional copper wired normally to the panel, because wiring to the ground seems like a bad idea.

Is this accurate?
Are there better/different/safer options?

Thanks,
Daryl
MN

220-volt LED lighting is readily available and surprisingly inexpensive. See, e.g.,
http://tinyurl.com/lrutnnt
This offering claims 2400 lumens which is about the output from a 150-watt halogen bulb.

 

[Dalton]

You can not get 110 volts off a 3 phase 3 wire. Be sure you have a 3 phase 4 wire. 3 wire will be 220v to ground (neutral).

 

[Smoky]

A couple of our machines at the shop are 220 3 phase with 120 accessories. Therefore they have 5 conductor feed. 3 for the 3 phase for the 220, 1 neutral (which allows the 110 from one of the 3 phase wires) and 1 Ground. That is the best I can do for you. Someone with RPC experience will know better than I.
Pierre

Hi, If you have a volt meter for AC then just measure each terminal against all the other terminals and as soon as you hit upon 110 vac you have a usable connection for lights. Between Neutral and any phase you should have 110 volts AC.

 

[rdhem2]

Darrell, lets go back to our friend the control transformer like I sent you. Wire it for 240v to 120v step down and hook your light up to it. A 250va xfmr will easily run the lights these other fellows recommend. Smaller xfmrs would work but may be stretching it as far as the load you put to it..
240v light bulbs come in many configurations but you won't find one at the grocery store. I would go the xfmr route if you want to stay professional like the machine manufacturer would probably do.

The light mksj suggests is a pretty sweet unit. Nice, bright, clear light and a swivel arm to boot.

 

[TOOLMASTER]

i got a jolt right across the chest
after one of the guys "fixed" the light that was damaged in shipping...i hit the switch with one hand while my other was on the table...#### that hurt.. needless to say i was #@&^%#@$#%&#&^%#%$#

it used a 220 bulb..ripped that crap right off and put up a 110 wall light

 

[John_Dennis]

Why not just run a separate wire to the nearest 110 plug? This way you will still have light when the machine is disconnected for maintenance. I have some of my lights wired to receptacles that are on the main garage light circuit. 1 switch turns all the lights on/off.

 

[John_Dennis]

The idea of LED lighting is good also - most of the newer LED lighting 120 or 220vac. Like this one:
http://www.amazon.com/gp/product/B00RES03VM
I use similar to this over my lathe and it really works good. OR - you might prefer something along these lines: http://www.amazon.com/dp/B007HZEJG2

Both these work on Input Voltage: AC 85V-265V

Let's see if I inserted the links properly.

Ken H>

I don't think that you can use 2 hots and no neutral on these lights. Remember that in the US, Canada, the standard household voltage is 110 per leg using a Neutral. In other parts of the world they use 250 and a Neutral. This is not at all like 2 legs of 110 which we call 220. In the US we also have 480, which is 3Phase 177 per leg. 177+neutral is used mostly for lighting. I have never seen it used for anything else.

The reason we use 110 here instead of 250 is that it is much safer.