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View Full Version : 220V Mill - pulled 110V off for accessories?



Rex
06-02-2010, 05:01 PM
I'm running a Millrite at 220V, which runs to a box the houses the F - Off - R switch. I need to add some low-vltage halogen and LED work lighting, plus a powerfeed. I have no 110V outlets nearby. Can I split 11-V off the 220V power and route it to a duplex plug mounted on the machine?

I'm no electrician, so don't use big words :)

darryl
06-02-2010, 05:13 PM
I don't see a problem with that as long as you have enough wires run to the machine. You need the neutral wire as well as ground and the two hots. If there isn't the neutral, the tendency is to use the ground as the return for the duplex outlet. That does give you 110 from either hot but is dangerous and not legal. Also, you have to consider the breaker rating. I believe if it's 15 amp or less, you would be ok, but if it's 20 amp, that would mean that you would use a 20amp duplex outlet, not the typical 15 amp rated one. If the breaker is rated more than 20 amp, that means you don't have the appropriate protection for the 110 duplex outlet you want to install.

If things look bad on these accounts, consider finding a transformer with a 220 volt primary that has the appropriate secondary voltage to run the halogens. Sounds like you will need a transformer anyway. You often would have the option to wire it for 110 or 220, since it's fairly common to have a split primary on a transformer. That would also then give you a source for 110 from that same transformer, of course within the power rating.

Carld
06-02-2010, 05:14 PM
If your using single phase 220v and you have two black hot wires, a white neutral wire and a green ground wire you can use one black wire, the white wire and the green wire if needed to get 110v. 110v will be with the black and white wire and the green is a mechanical ground.

If your running the mill with 3 phase that will NOT work.

Bguns
06-02-2010, 05:18 PM
If you have a neutral run out to machine (doubt it) you can split it.

220 single phase has 2 hot wires, a neutral and a ground. 4 wires total. That costs extra so often only 3 wires are run to machine (no neutral)

Ground should be green or bare... 110v from a hot wire to neutral. DO NOT WIRE TO GROUND INSTEAD OF NEUTRAL

Another easy way is to just get a 220 to 110 transformer and get your power that way, if you only have 2 hot wires going to machine.E

Edit:should type faster :)

Also put a fuse on 120 volt side to protect the sub circut.

Falcon67
06-02-2010, 05:18 PM
Maybe - 220V single phase motor circuits do NOT require a neutral, just two hots and a ground.

SO - you have to look in the panel and in the box at the machine - if there is a neutral run to the machine from the panel, then yes you can snag some light 110 off the circuit. If there is no neutral, you may have to re-pull the circuit with three wire cable plus ground. Depends on the run and code, and I'm not a code expert.

macona
06-02-2010, 06:06 PM
Or stick a small 240-120 control transformer on there and run your stuff off that.

lost_cause
06-02-2010, 06:36 PM
my quick answer would be: probably not.

let me also add that i'm not an electrician, but i have done a lot of research and learning over the course of owning two homes that have often had poor and even incorrect wiring - some done by licensed professionals. due to this, my terminology may not always be perfect, but i try to use layman's terms to explain.

i'm going to start by assuming that you do in fact have a single phase device. if you didn't, you would have probably mentioned that you were using a phase converter or other device to create three phase power for the motor.

a 110v (120v) device will have three wires - hot, neutral, and ground. a 220v (240v) device will have two hot wires and one ground wire, but no neutral. in both of these systems, the ground wire is only intended to carry current in the event of a fault. it should never be substituted for a neutral wire, which is the return leg of the power circuit. the 220v circuit does not have a dedicated neutral, so what happens is that when one hot wire is carrying current, the opposite hot wire is acting as the return for the circuit, and they alternate in this fashion. since the 220v circuit does not require a neutral, you are unlikely to have a neutral wire to act as the return for your 110v circuit.

generally, neutral wires are white in color, but never make the assumption, because most three stranded wire and cord is made for 120v use and will have a black (hot) white (neutral) and green/bare copper (ground). it is perfectly acceptable to use this wire and cord in 240v applications, but you are SUPPOSED to re-color the white wire to black, red, or pretty much anything but green or white to indicate that it is a current carrying wire. this does not always get done due to laziness. do not assume that white is neutral if you have a 240v device.

the only way to be visually sure is if it is a 120v/240v device, meaning that it uses both 120v and 240v, such as a newer clothes dryer. generally 240v powers the heavy stuff - heating/motor, and the 120v would be for any electronics. these devices are easy to identify as they will have a 4 wire cord and plug (hot/hot/neutral/ground) if it's 240v and has 3 wires, then you do not have a neutral.

rklopp
06-03-2010, 11:58 AM
I ran into the same issue on my Aciera F4. To get 120 V for the DRO and worklamp, I added a 240->120 control transformer. Then, I grounded one leg of the 120 V side to make a "separately derived" source to the machine's frame, which is of course itself grounded. This effectively became my local neutral. I wired the lamp and DRO so that the local neutral was connected to the lamp's threaded shell and to the DRO plug's wider blade.

I included fuses on the input and output of the transformer, which was a 200 VA unit from Factorymation.

MaxHeadRoom
06-03-2010, 01:59 PM
If you don't have a neutral and use a 240/120v transformer you can set up a local neutral in the enclosure, you do this by grounding one side of the secondary to the service ground and enclosure, from this point you also run the 'new' neutral.
Control panels are set up this way as a rule.
Do NOT use the ground as a neutral at any time.
The code allows the option of the 120 remaining isolated or a grounded neutral done as above.
If isolated then a fuse or breaker is used in both legs, if grounded neutral then fuse only the hot side.
Max.