The case for 220?

Discussion in 'Woodturning Discussion Forum' started by John Turpin, Aug 9, 2017.

  1. Mark Wollschlager

    Mark Wollschlager

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    Our club had access to a school shop with ceiling mounted power cords.
    I hated those things because the plugs hung about 6ft from the floor and the top of my head is about 6' 2".
    Great when they were connected to a piece of equipment in the middle of the shop.
    Not so great when they were just dangling. I would knot them up higher, someone else would let them down. ;)
     
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  2. Doug Rasmussen

    Doug Rasmussen

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    Has anyone mentioned potential problems converting a motor from 115V to 230V?

    One is having to change the overload coils if present in a switch or motor starter. They aren't always easy to find for older devices.

    Another is with old motors the wiring diagram may be missing or illegible. Or, the wires are not labeled or they may be color coded and the colors have faded badly over the years.

    Sometimes with old motors the wire insulation has become brittle and you can't rebend a wire to attach to a different screw terminal.

    Over the years I've had all the above problems and more.
     
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  3. John Torchick

    John Torchick

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    Not doubting your comment but I'm going to check it out. I was not taught that way. Why do panel boxes had a neural bar and a common wire bar? Have they changed? Have a friend who is a licensed electrician. Will see if I can catch him between work and sleep.
     
  4. Bill Boehme

    Bill Boehme Administrator Staff Member

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    They have a grounded bus and an insulated bus because the panel might be used elsewhere than a service entrance. Normally supplied with a panel is a grounding kit for use as a service entrance panel. There are generally instructions, sometimes a tag about grounding the neutral at the service entrance. In order to prevent ground loop currents, the two are not connected together at any other place in the wiring system. Likewise, ground rods are not allowed at sub panels. And here is something that is important to woodturners as I have seen bad information posted: You do not connect the frame of stationary machinery to a separate earth ground.

    Here is one explanation of Article 250 (Grounding and Bonding) of the National Electrical Code that I found on the Home Improvement Stack Exchange.

    BTW, neutral is also generally tied to earth ground at the distribution transformer.
     
  5. John Torchick

    John Torchick

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    Thanks Bill. Never had the need for a sub-panel. I know when I did some electrical work in KY, that common and ground were separated. There was no sub-panel. Never really paid attention to the inside of my panel box. I did add one breaker to run a 120V line to the shop.
     
  6. Bill Boehme

    Bill Boehme Administrator Staff Member

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    I have the impression that I may have created more confusion than clarity, so, just to sum everything up in one simple sentence: Neutral and ground are separate everywhere EXCEPT FOR inside the service entrance panel.

    If you run any branch or feeder circuits you must keep the two separate from one another. The reasons include:
    • Ground is for safety only. It is not a current carrying conductor.
    • Neutral is a current carrying conductor and as a result it won't be at the same potential as ground because of I²R losses in a current carrying circuit.
     
  7. John Torchick

    John Torchick

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    Odd, never heard of that. Thanks. How long has this been in the NEC? I worked in the appliance industry in R&D and model shop and we had to improvise with four wire cords and three wire connector blocks in working on new models. Now I think all ranges and dryers are four wire systems.
     
  8. Bill Boehme

    Bill Boehme Administrator Staff Member

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    That's been in the NEC since the beginning of time or at least since grounded plugs started being used ... probably about the mid 1960's.

    Speaking of appliances, I spent the entire day working on our clothes dryer. The serviceman was here at 7:30 AM and after a couple hours he gave us the bad news ... the main control board was bad and the cost to repair it would be about $850 parts and labor. We said, "thanks, but no thanks" and paid him for the service call. As soon as he was gone I had the dryer opened up again and after a few minutes I found a loose connection. I had it running again, but it wasn't venting properly so I cleaned the lint out of the vent line, buttoned it up, and we were back in biz. I found information online on how to run a diagnostic self test on the control board and it checked out perfect. We've been running it all day drying clothes and it's still humming along. BTW, Amazon listed the control board for a third of what the servicemen said it would cost. All of this is actually irrelevant to what I was going to say about power to appliances. The manual says that a 4 wire outlet is preferred, but it can be wired for a 3 wire outlet because all the electrical stuff is double insulated. I noticed that the outlet in our laundry room is the 3 wire type which means that we have the two high legs and neutral. The fourth wire would have been ground which is only connected to the metal frame. The reason for the neutral is that 120 volts is needed to power the control electronics and the light bulb. Same thing is true for ovens. This is different from 240 volt woodworking machines where the third wire is ground since neutral isn't needed. Being an engineer, I can't do things the normal way ... so I have a 4 wire connection to my lathe because I have lighting and a power strip.
     
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  9. charlie knighton

    charlie knighton

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    I could have used you a month ago Bill.....I would recommend just say no if the appliance dealer ask to deliver the appliance out of the box......
     
  10. John Torchick

    John Torchick

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    :D Know what you mean. My son is an ME, graduated with honors. Must have been due to a genetic mutation.
    As I think I had mentioned, I helped a fellow wire and plumb a house. We separated the common and ground in the main panel and passed inspection in KY in about 1980. Only had to add one vent in plumbing at the suggestion of the inspector. Made us feel good. M parents built a house in 1970 with two 200 amp boxes. Again, wires were separated and passed. Will back out as we could go on and on with this. My grandfather would check for juice by licking his thumb and index finger and pinching a wire. If it tingled, it was hot! What a guy!!!!
     
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  11. Ely Walton

    Ely Walton

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    You may want to check the type of power switch used... Machines delivered for 115V may have a motor that can be wired for 230V -- but if you change, make sure the power switch is double-pole -- if not, switch the switch.... :>)

    Ely
     
  12. John Torchick

    John Torchick

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    I spent some time this weekend with an electrician- IBEW Local 175. I put the question to him about common and ground wires. Here is what he said-
    The common and ground can be put on the same bar in the main panel box or they can be separated. However, when running a subpanel off of the main panel, the ground and common wires are to be separated.
     
  13. Bill Boehme

    Bill Boehme Administrator Staff Member

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    That's right. Just for neatness, I prefer putting the neutral (white) and ground (bare or green) on separate bus bars in the service entrance panels and bonding both of the bus bars to the case. On sub panels, the neutral bus is insulated from the case while the ground bus is bonded to the case. The purpose is that you want neutral to have only a single point connection to ground.
     

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