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-   -   Ground and neutral Wires (https://www.askmehelpdesk.com/showthread.php?t=183002)

  • Feb 11, 2008, 04:10 PM
    mr500
    Ground and neutral Wires
    Is it proper to connect the ground and neutral to the neutral buss? I am installing a sub panel from a 200amp svc to a 125 service using 6g. My sub box does not have a separate ground buss rather only 2 neutral buses with a crossbar. I was informed that I can put the neutral and ground on that same buss. Is this correct or SAFE? Would it be safer to get another bus and install in the box for my ground and ground that to a ground rod?? Any help will be appreciated. TIA Mike:)
  • Feb 11, 2008, 05:28 PM
    tkrussell
    If the main breaker is in that panel, then the neutral and ground are connected, and only here. In any subpanel that does not have the service main breaker in it, the neutral is kept insulated from any equipment ground.

    There should be an equipment ground wire along with a neutral feeding any subpanel, or 4 wires with the two hots.
  • Feb 11, 2008, 06:03 PM
    mr500
    OK! So I need to buy an equipment ground bus and add it. I know that there are 2 threaded holes in the panel so I assume this is where the buss will be added. I also understand that the neutral must be kept free of the box itself via insulated tabs etc..

    Also, in your opinion will I need 6-3 w/ground. Will the ground on the sub panel need a rod, or will the grounding via the main panel in the house be sufficient?

    TIA Mike
  • Feb 12, 2008, 03:54 AM
    tkrussell
    Yes, #6-3 with ground is what is needed for a 60 amp feeder to a subpanel.

    Yes, the threaded holes are for a separate equipment ground bar, which always must be bolted into a metal can using machine thread screws.

    A ground rod is only needed for a subpanel that is in a separate building, never for a subpanel that is located within the building that contains the Main Service Disconnect.

    Otherwise seem you have a good handle on this.
  • Feb 12, 2008, 03:22 PM
    mr500
    OK Great. THANKS!! The sub is not in the same building so I guess a ground rod is necessary. Any requirement on how deep?

    Also dumb question number 2 is, if I am running 20amp breakers, should I go with the 14-2 as opposed to the 12-2 since 14 is rated for 20 amps, AND should I go with 20 amp plugs instead of the 15 amp ones so as to keep everything the same amperage?

    Just want to make sure I don't blow something up on this little venture I am about to fore take.

    Thanks SOOO for all the help. The guys at Depot & Lowe's should be in here reading these forums as well!! Good Stuff!! :)
  • Feb 12, 2008, 03:47 PM
    tkrussell
    A standard ground rod is 5/8" dia x 8 feet long, and every bit of the rod needs to be driven in, and the clamp needs to be just below grade, and the clamp needs to be rated to be direct buried. A popular ground rod clamp is called an Acorn clamp, and fits the job perfectly.

    The rod may be driven in an angle up to 45 Deg if there is ledge or some other obstruction, or can be laid horizontally in a 30 " trench if necessary.

    Best to check local codes, as many areas require at least two ground rods.

    OK here is where I think I need to take back my comment you have a handle on things, I sure am glad you asked the question:

    The only location I can think that you have seen #14 copper wire rated at 20 amps is in the National Electric Code Table 310.16. If this is the case, or you have seen a wire chart derived from this table, please note off to the left the asterisk next to #14 wire, along with #12, and #10 wire.

    The asterisk directs you to a foot note at the bottom of the table that states :*See 240.4 (D), which then states that "the overcurrent device shall not exceed 15 amperes for #14 wire, 20 amp for #12, etc."

    So, short answer is #14 wire cannot be connected to a 20 amp breaker, a 20 amp circuit must use #12 wire, for all general purpose wiring.

    As far as receptacle, you may use 15 amp receptacles on a 20 amp circuit, just each receptacle will be limited to a 15 amp plug. If you expect to use any truly 20 amp rated tools or appliances, then use 20 amp receptacles.
  • Feb 12, 2008, 04:02 PM
    Stratmando
    #6 won't be good for 125 Amps, Its about a #1(I don't have code book handy, and don't do a lot of 125 Amp). #6 is not big enough.
  • Feb 12, 2008, 04:48 PM
    mr500
    8ft rod.. Now that's going to be FUN lol OK!! So Im going with 12-2 and the common 15 amp plugs. The largest tool I have is right at 15 amps, so I should be OK.


    And, 6-3 w/gnd with a 50 amp breaker in the sub. Ill be adding the equipment grnd buss as stated earlier. That should do me just fine.

    Again thanks for all your help in this matter. I feel this job won't turn into a nightmare!! :)
  • Feb 13, 2008, 06:06 AM
    Stratmando
    If it will make you better about the Ground rod, We Have to Drive through Coral and Cap Rock, you can pound for 10 or more minutes and it won't move.
    You could use 60 Amp Breaker with #6
  • Feb 13, 2008, 03:12 PM
    mr500
    60 amp? Humm. I actually thinking about running #1 wire ang get the whole 125 amps from the panel. But money might be a factor there as it usuall is.

    Lol. Well I hope I don't hit any rocks, but here in Alabama you never can tell what you might hit when diggin. Pounding for 10 min id be passed out... Break time lol

    Thanks for all the advice!!

    Mike

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