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  • neophyte
    replied
    I am just going to have the electrician come back out and run a fourth wire back to the house. He should have done it that way to begin with. Thank you guys for all the help..... you are what makes this board a great place to visit.

    Leave a comment:


  • burninbriar
    replied
    Basically what they are saying is that if you have a separate equipment ground, they don't want it to be able to carry current from one building to the other witch would be picked up from the neutral bar at the garage if they were bonded there, and they want you're neutral to have a direct path to the transformer center tap through coated wires.Once the equipment ground is as close to the transformer as it can get, it is bonded to the neutral so it also has a path to the transformer center tap, this is because the center tap of the transformer is the only suitable ground to trip a breaker. To understand this you must accept the fact that neutral and ground are totally different. One is non currant carrying and the other carries current. I know some here don't believe that, but if it were not true, these rules would make no sense at all.

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  • harcosparky
    replied
    I looked at the link again.

    Basically IF you have an " equipment grounding " conductor run from the house to the garage/shop in the main feed 'marrying' the neutral and ground in the garage/shop panel is not necessary. It's already done in the main panel at the house.

    Look at the two attached pics. Notice they show 4 conductors coming into the subpanel from the house, subpanel ground and neutral are NOT 'married", however the main panel in the house shows them 'married'.

    ALSO - the Notes they refer to in those images are not the same note I posted earlier. Each image has its own set of applicable notes.
    Attached Files

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  • neophyte
    replied
    Originally posted by harcosparky View Post
    Is the 3 wire feed from your house buried or is ot overhead?
    In conduit... I will have another look at the link.
    Thank you.

    Leave a comment:


  • neophyte
    replied
    Originally posted by dcsound View Post
    Whether it's code or not, I personally don't like the practice of using the white as a hot conductor even if it has been marked in the panel. Even if the wire in color coded at both ends, it may not be coded in any intermediate junctions, so if one would try to tap it in the middle they would not know exactly what they have.
    A very valid point..... that is part of the reason it is not allowed if run in conduit. The reasoning being that it should be easy enough to pull in another wire. In my situation it was a dedicated outlet for the air compressor with no intermediate boxes.

    Leave a comment:


  • harcosparky
    replied
    Originally posted by neophyte View Post
    My sub-panel in the garage has three wires coming into it from the house. There is a ground rod at the garage that was connected to neutral bar. I added a ground bar to the box so to keep my neutrals and grounds seperated. (Looks cleaner that way to me.) The inspector told me to remove the grounding wire attached to the ground rod from the neutral and place it on my ground bar.... and to seperate the neutral and the ground bar in the garage box. Also to seperate the ground bar and neutral bar on the 40 sub-panel to the RV (8-3) that comes from my garage box. That kind of smacks Note 6 in the face. I am back to the learning curve looking like a globe again.

    Is the 3 wire feed from your house buried or is ot overhead? There seem to be several variables on this. Look at the URL I posted they show several scenarios. Even one taking into consideration if you have water running from the house to the garage/shop. Some have the Gnd/Neu tied together, others not.

    That seems to make a difference. Once again though, it goes back to what the Local Code/Inspector says.

    Leave a comment:


  • ctardi
    replied
    If the machine is not using Neutral(white), is it not better to leave it disconnected at BOTH ends? Reason Being, we don't want someone to tap into the middle, and run a 110V plug in there. If Neutral is not connected at the panel, the plug will not work.

    Although this compressor is using three conductors, it is still grounded. Chances are this is how your welding machines are hooked up, using a NEMA 5-50.



    It uses 2 hots, and a ground. No Neutral.

    Neutral is the Power Companies Ground that comes from the pole to your house. In addition to that, you have a grounding rod or other applicable grounding source on your property. These are usually both tied together (bonded) in your main panel, but nowhere else. This keeps them at the same relative voltage so that you do not get zapped by touching them.

    Now, since the NEMA 5-50 provides 220V, and only has 3 contacts, we do not use neutral. We use two hots of opposite phases and Ground.

    Now, it is unusual to find a piece of Romex (sheathed wires like your house is done with) with two hots, and a ground, and no white. So to save costs, sometimes you can get a piece with a hot, a white, and a ground. In some areas, you CAN re-mark the white to be a hot, but it has to be done at both ends, if it is allowed.

    It is not always allowed, so we have a couple of options. Run our 3 wires in a conduit, or use 12/3 romex. The Former is probably more expensive, depending on length of run.

    Without getting into too many details, if you don't understand that, hire an electrician to do it for you.

    Leave a comment:


  • dcsound
    replied
    Whether it's code or not, I personally don't like the practice of using the white as a hot conductor even if it has been marked in the panel. Even if the wire in color coded at both ends, it may not be coded in any intermediate junctions, so if one would try to tap it in the middle they would not know exactly what they have. I hate it when I open up a panel and find a white wire connected to a hot terminal of a breaker without being marked at all. I do see a lot of this type of install. Besides seeing 2 conductor wire without a neutral used for 240V circuits, I see a lot of 3 conductor wire being used without a neutral for three phase circuits with white being used as the third hot. The proper color for the third hot leg is blue. I definitely understand why the inspectors wouldn't be happy with these sorts of things. Much better to run the white conductor as the neutral even if the machinery doesn't require it.

    Leave a comment:


  • neophyte
    replied
    My sub-panel in the garage has three wires coming into it from the house. There is a ground rod at the garage that was connected to neutral bar. I added a ground bar to the box so to keep my neutrals and grounds seperated. (Looks cleaner that way to me.) The inspector told me to remove the grounding wire attached to the ground rod from the neutral and place it on my ground bar.... and to seperate the neutral and the ground bar in the garage box. Also to seperate the ground bar and neutral bar on the 40 sub-panel to the RV (8-3) that comes from my garage box. That kind of smacks Note 6 in the face. I am back to the learning curve looking like a globe again.

    I am beginning to think I should have the electrician come back out and just run a fourth wire back to the house. Looks to me like he is going to have to tear it up anyway to replace the schedule 40 conduit he put in. Atleast that way I can run low voltage from the house to the garage.

    Leave a comment:


  • flukecej
    replied
    harcosparky,

    That was a great article and excellent reference you posted. For basic branch wiring, that was the most complete and easy to understand that I have ever seen. Excellent find and great post.

    Leave a comment:


  • harcosparky
    replied
    Originally posted by Steve View Post
    Just for grins, lets wire the 220 motor with just the two wires. Did you know one leg of the 220 can short out to frame and the motor will still work just fine. YOU wont work just fine if you grab the HOT frame. Severe case of the giggles will occur. So you need to have the frame gounded thus the third wire. And for other cases do not confuse the neutral return with the grounding wire. Neutral return is white, grounding wire is green or the uninsulated wire.
    I was told that long ago dryers were wired with only 2 wires, and yeah people at time got a case of the giggles. I was looking at a schematic for a new dryer. They show the 4 wire hookup, red + black ( hots ), white ( neutral ), green/bare (grounding). Coming out of the dryer the white and green/bare originate from 2 places but at the other end they are hooked together. An electrician who lives down the road told me the "neutral" in the dryer has a potential for carrying current and needs to be insulated.

    Basically he said you could tie the neutral and ground together inside the dryer so long as the 3rd conductor in the feed back to the panel is insulated.

    I found this diagram on a website someone posted in another thread, it deals with running a feed from the house to a detached garage/shop. Basically it says if the feed from the house does not carry a grounding conductor the neutral and ground bus in the box must be tied together. It references a " Note 6 " which I have copied here.

    Note # 6 – When the detached garage disconnect is supplied by a feeder that has no equipment grounding conductor ran with that feeder, from the main structure {usually dwelling** to the detached garage, then the neutral bar, and equipment grounding bar must be joined or married together as one entity, usually by a jumper bar attached between the two bars or by a jumper bar connecting the neutral bar to the metal of that panel box and the grounding bar bolted directly to that metal of that panel box. Article 250-32-B-2 & 250-102-E The neutral bar must married or joined together with the metal of the panel box and also the equipment grounding bar. Article 250-32-B-2
    http://www.selfhelpandmore.com/homew...rage/index.htm
    Attached Files

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  • Steve
    replied
    Just for grins, lets wire the 220 motor with just the two wires. Did you know one leg of the 220 can short out to frame and the motor will still work just fine. YOU wont work just fine if you grab the HOT frame. Severe case of the giggles will occur. So you need to have the frame gounded thus the third wire. And for other cases do not confuse the neutral return with the grounding wire. Neutral return is white, grounding wire is green or the uninsulated wire.

    Leave a comment:


  • Pile Buck
    replied
    Originally posted by flukecej View Post
    Since 1992, I have had to run 4 wire subcable with all pumps set or add a ground wire to the existing 3 wire subcable in place because the motor manufacturer and NEC said it had to be done, even with the pump set on steel pipe. That ground wire is needed for a reason, its called safety.
    This is exactly how I had to do my daughter’s well house!

    Leave a comment:


  • neophyte
    replied
    Originally posted by flukecej View Post
    neophyte,

    The sole reason the inspector is wanting you to use 12/3 is because the compressor has to be GROUNDED. Yes it will run on 12/2 but it is not up to code without being grounded. You can go down to Home Depot or Lowes and buy a cut length of 12/2 with ground or 12/3 cable and get the job done. You don't have to buy a whole roll of wire unless you like parting with your money.
    I originally ran 12-2 with ground.... sorry for any confusion.
    This is a 240-volt compressor..... two hots and one ground ....no other available lugs in the Air Comp switch. His soul reason for running 12-3 with ground is so I could run red-hot and black-hot instead of white hot reidentified as black and a black hot. The later is to the NEC 2005 code.

    Yes, a Lowes or Home Depot would be nice.... don't have either here in this big city.

    Leave a comment:


  • flukecej
    replied
    neophyte,

    The sole reason the inspector is wanting you to use 12/3 is because the compressor has to be GROUNDED. Yes it will run on 12/2 but it is not up to code without being grounded. You can go down to Home Depot or Lowes and buy a cut length of 12/2 with ground or 12/3 cable and get the job done. You don't have to buy a whole roll of wire unless you like parting with your money.
    I'm am in the water well service business here in TX. I am constantly updating wiring on domestic wells to put that third wire or ground in place becuase the code says it has to be there. We used to use 12/2 UF cable from the disconnect or breaker panel to the control box. These days, the 12/2 has to be replaced with 12/2 with ground or 12/3 SDT (tray) cable to meet code requirements, even out in the country. In TX, the NEC applies everywhere, county and local codes can add to but not weeken the NEC requirements. Since 1992, I have had to run 4 wire subcable with all pumps set or add a ground wire to the existing 3 wire subcable in place because the motor manufacturer and NEC said it had to be done, even with the pump set on steel pipe. That ground wire is needed for a reason, its called safety.

    Leave a comment:

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