How to wiring the power wires of mashine to Mains.

Discussion in 'General Electronics Chat' started by Steelcutter, Sep 22, 2015.

  1. Steelcutter

    Thread Starter New Member

    Sep 22, 2015
    Ok so I'm in an old building we have black, red and that's it. I had and old dryer and it ran fine.
    Now the new dryer has white black red and a ground green.. I run a welded and a planner using the
    black red and a ground wire. I can't get the new dryer to run. I have tried black red and the white
    to ground then the green to ground then both white and green to ground. It runs then shuts off?
    10 seconds or so. Do I need to switch black and red>? Or did I get a bum dryer? Or is the old
    single phase not going to run a new dryer?

    Mod edit :
    Please don't hijack other member's post, now you have your own.
    This thread was split from -- single or 3 phase in my home?
  2. tcmtech

    Well-Known Member

    Nov 4, 2013
    Is your original three wire systems ground wire actually connected at the other end to both the common and earth connections in your fuse/breaker panel so that you have a reading of 120 VAC from black to ground and 120 VAC from red to ground and 240 VAC across the black and red wires with a minor load like a 100 watt light bulb on the 120 VAC connections?

    If not your ground lead is either floating and connected to nothing at the other end or is tied to an earth ground point only and not sharing a common tie to the white common at the fuse/breaker panel like it should be.
  3. wayneh


    Sep 9, 2010
    I agree. You need to sort out if you had - or have now - a single/dual phase appliance and a single/dual phase supply. And then also determine whether it is properly wired and grounded.
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    You should hire an electrician before you get hurt or create a potentially unsafe situation.
    Don't just start "trying" things.. Thats stupid.

    If you won't then..
    at the very least tell us what country you are in
    the electrical specs of new dryer?

    my initial "guess" is you have 120V(110) and the dryer is expecting 240V(220).
  5. #12


    Nov 30, 2010
    This takes me back. Many appliances in the 1970's had both 120V and 240V loads, but there were only 3 wires in the outlet. The 120V loads were ground returned through the bond wire. Seems illegal to me! Are they still doing it that way? Three wires in the power cord to the dryer?

    @Steelcutter You need to trace all the way back to the breaker box/fuse panel. Even if the dryer is equipped with a 3 wire plug, you still have a foul in the wiring. In America it's supposed to be: red and black make 240 volts. Red to white or black to white makes 120 volts. White is supposed to be grounded at the fuse box where it meets green wires and naked wires.

    Then again, there was that one installation in 40 years where the customer was sure I didn't wire the outlet right because the brand new cord that came with the dryer was faulty.:rolleyes:
  6. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
    It help to have general idea where on the planet you are in this case. Anyway see here:

    We have to make some assumptions. Black/Red would mean 240 V. If the box is metalic and it's connected via conduit, then ground is the conduit. The cable could even be bx or armoured cable.

    We have to assume the old dryer was all electric and the new one is too usually dictating 240 V.

    The old dryer really should have had 3 wires and the new would have 4 wires. You can covert these by changing the cord and making some strap changes.

    Two wires, red and black is a bit odd. This, to me suggests metalic conduit. My crystal ball isn't working very well.

    New dryers, especially the pedistal models, have drastically different service requirements.

    What do you need: see the nameplate
    What do you have: breaker, wire size, length to breaker box

    Can you convert?
    Should you re-wire?

    The "new" standard is to have L1, L2, N and ground. The old kinda bonded N and G together at the dryer.

    The "new" dryer may actually have a nice terminal block with the appropriate jumpers.

    Some pics could help. A link to the owners manual of the new dryer would help too.