240 to 120

[telescope1]

I have a 240 drop with 4 wire cable + gd.
I need to go from 240 down to 120 & install a 4 outlet box, then go back to two wire plug (240) after that. It is a cieling cable drop.
Any suggestions?

[mdshunk]

If your drop is 4 wire buss drop cable plus a ground, that makes 5 conductors total, right? This sounds like a 120/208 or 120/240 three phase cord drop. In any event, repost with exactly how many conductors you do have and the colors. For 4 total wires, you should have black, red, white, and green in the consist of the cable. For 5 total wires, you should have black, red, white, blue, and green in the consist of the cable.

It is quite possible to do exactly what you desire to do with this cord drop. Repost with the colors of the conductors and we'll spell it out for you. If you know, post the amperage of the breaker serving this cord drop, and the amperage of the receptacle that's on the end of this cord drop now. Also, the regular outlets that you wish to add... are they for regular 120 volt stuff with regular attachment cords? Answer these questions and we'll get you pointed in the right direction.

[telescope1]

Received your advice & thanks a lot for your time!
Actually the wire cosists of red, black, white, orange.
It IS a buss drop cable, and there were 3 boxes connected.
The first was used as a 240 3 phase outlet, but I am removing that, as it will no longer be used.
The second box had a 120 2 outlets, which I am changing to a 4 outlet.
The 3rd box has a simple 240 outlet with just two wires, (a blue one added in the 120 box and the original black from the buss cable.
I can't tell you the amperage, but i don't think there's much to worry about there, as the 3-phase will no longer will be used and the 120 will only service small stuff, radios, etc.
Thanks for your help!

[mdshunk]

The reason I inquired about the amperage of the breaker is because I'm worried that it may be too high. If you install regular 15 or 20 amp receptacles for your radios and lights and stuff, this cable may be served by a 30 amp or greater breaker (causing you to be in violation). If you have this cable on a 15 or 20 amp fuse or breaker, you're in fine shape.

To connect the regular receptacles, connect the brass colored screw on the receptacles to any ONE of the black, red, or orange conductors. Connect the silver colored terminals to the white wire. Connect the green screw to the green wire.

To proceed to the straight 240 receptacle, connect two different hot wires to the brass colored terminal screws (eg.; black on one and red on another, or red on one and orange on another.) The white neutral wire will not be used on a straight 240 receptacle. Connect the green ground wire to the green ground terminal on the 240 receptacle. Simple as that.

For future reference, your cord drop consists or three hots (black, red, and orange), one neutral (white), and a ground. You get 240 single phase by connecting to any two hot wires. You get 240 three phase by connecting to all three hot wires. You get regular 120 by connecting to any one hot wire and the white neutral. Of course, all types of receptacles get the green ground wire attached to the ground terminal.

[Homer]

Be sure to check that you don't have a 4-wire delta supply where the orange conductor is the high or crazy or wild leg.

If you do have a 4-wire delta supply then the orange to white would be 208V, not 120V while the black to white and red to white would be 120V.

A 4-wire delta supply has a center-tap on one of the windings where the 'neutral' connects to allow for 240V/120V, single phase along with 240V, 3 phase.

It only takes a second to measure the voltage between orange and white to make sure.

Here's some supply configurations (http://www.bmillerengineering.com/elecsys.htm) to look at. I'm refering to the second from the bottom one.

Homer

[mdshunk]

True enough. It totally slipped my mind that your building could have a "delta high leg" service. In this case, the voltage from any hot wire to the neutral would be 120 volts, but from the orange (high leg) to white neutral would be about 208. Thanks for catching that one, Homer. Check the voltage as he suggests. May be true in your case, may be not.

[telescope1]

MDSHUNK & HOMER,
Thanks a lot for your time & advice and will put it to good use tomorrow.
Have a great evening!