wiring up a 30A 220v outlet

Discussion in 'Misc DIY' started by xrongor, Jun 24, 2004.

  1. xrongor

    xrongor Guest

    i just got done wiring my garage and as we forgot to buy one, he just told
    me to go buy one later and put in a 220V 30A outlet. we wired it to the
    panel and all, just left the wires loose in the box which is located right
    below the panel.

    the electrician told me to run the copper wire to the neutral prong instead
    of the white wire. his reasoning was that a loose copper wire in the box
    could accidentally touch one of the lugs that was hot, but you could just
    wire nut the neutral and it wont touch anything. this way i dont have to
    trim off the copper ground wire and if i ever need to i can switch to a 4
    prong outlet instead of a 3 prong one.

    now i know how the neutral and the ground are related and connected, and i
    dont see a problem. but im not an electrician.

    so my question is, is the inspector gonna have a fit or is this a common
    practice?

    randy
    xrongor, Jun 24, 2004
    #1
  2. xrongor

    Eric Tonks Guest

    The bare copper wire in all cases should be connected to the ground prong
    not the neutral prong (you will only have a neutral prong if you have a four
    prong plug/receptacle which is used for 120/240V outlets, 240V [only]
    outlets will NOT have a neutral prong). In no cases would the bare copper
    wire be left loose in a box, it would be attached to something!

    "xrongor" <> wrote in message
    news:...
    > i just got done wiring my garage and as we forgot to buy one, he just told
    > me to go buy one later and put in a 220V 30A outlet. we wired it to the
    > panel and all, just left the wires loose in the box which is located right
    > below the panel.
    >
    > the electrician told me to run the copper wire to the neutral prong

    instead
    > of the white wire. his reasoning was that a loose copper wire in the box
    > could accidentally touch one of the lugs that was hot, but you could just
    > wire nut the neutral and it wont touch anything. this way i dont have to
    > trim off the copper ground wire and if i ever need to i can switch to a 4
    > prong outlet instead of a 3 prong one.
    >
    > now i know how the neutral and the ground are related and connected, and i
    > dont see a problem. but im not an electrician.
    >
    > so my question is, is the inspector gonna have a fit or is this a common
    > practice?
    >
    > randy
    >
    >
    >
    Eric Tonks, Jun 24, 2004
    #2
  3. xrongor

    Chris Lewis Guest

    According to xrongor <>:
    > i just got done wiring my garage and as we forgot to buy one, he just told
    > me to go buy one later and put in a 220V 30A outlet. we wired it to the
    > panel and all, just left the wires loose in the box which is located right
    > below the panel.


    > the electrician told me to run the copper wire to the neutral prong instead
    > of the white wire. his reasoning was that a loose copper wire in the box
    > could accidentally touch one of the lugs that was hot, but you could just
    > wire nut the neutral and it wont touch anything. this way i dont have to
    > trim off the copper ground wire and if i ever need to i can switch to a 4
    > prong outlet instead of a 3 prong one.


    So I understand this - you installed four wire (bare ground, white neutral, black
    and red hots, wired properly in the [sub] panel) to a three prong 240V receptacle.
    Right?

    And the electrician is recommending you connect the white wire (not the bare
    ground) to the receptacle ground.

    > now i know how the neutral and the ground are related and connected, and i
    > dont see a problem. but im not an electrician.


    They're connected together in the main panel. Not in subpanels. Since this is
    a garage, this may be a subpanel.

    If you're using a subpanel, you're connecting the ground to the neutral in the subpanel
    feed. Not the ground. It's not connected to the real ground until back in the
    main panel. If you ever lose the neutral between main and subpanel, the case
    of whatever you have attached to the 30A outlet goes live.

    If you lose the neutral in the main panel, _everything_ grounded could potentially
    go live (not _because_ of wiring that outlet to neutral, but potentially worse
    hazard because of it).

    This is equivalent to the old three wire stove and dryer connections which
    are no longer legal in the NEC, and hasn't been legal in the CEC for decades.

    Ground MUST NEVER rely on neutral connectivity.

    > so my question is, is the inspector gonna have a fit or is this a common
    > practice?


    The inspector will have a fit. Violates colour codes too.

    Best approach is to use the bare ground, (making sure that bare ground is connected
    to box _too_ if it's metal) and cap off the white in the receptacle
    box in case you ever convert to a 4 prong.

    If having the bare ground come in contact with the hots is a concern, you
    shouldn't be fiddling around with the receptacle.
    --
    Chris Lewis, Una confibula non set est
    It's not just anyone who gets a Starship Cruiser class named after them.
    Chris Lewis, Jun 24, 2004
    #3
  4. xrongor

    xrongor Guest

    just a quick response to whats been posted so far:

    the box is a fiberglass box hence no ground lug is there, or needed. maybe
    code calls for a metal box...

    anyway, ill ask him about it next time i see him.

    thx

    randy

    "Joseph Meehan" <> wrote in message
    news:xxICc.21$...
    > xrongor wrote:
    > > i just got done wiring my garage and as we forgot to buy one, he just
    > > told me to go buy one later and put in a 220V 30A outlet. we wired
    > > it to the panel and all, just left the wires loose in the box which
    > > is located right below the panel.
    > >
    > > the electrician told me to run the copper wire to the neutral prong
    > > instead of the white wire.

    >
    > Not good.
    >
    > > his reasoning was that a loose copper
    > > wire in the box could accidentally touch one of the lugs that was
    > > hot, but you could just wire nut the neutral and it wont touch
    > > anything.

    >
    > He needs to stop guessing and read the code.
    >
    > > this way i dont have to trim off the copper ground wire
    > > and if i ever need to i can switch to a 4 prong outlet instead of a 3
    > > prong one.
    > >
    > > now i know how the neutral and the ground are related and connected,
    > > and i dont see a problem. but im not an electrician.

    >
    > The neutral and ground are connected to the same source at the main
    > panel, only. There is a strip for connecting neutrals and one for

    grounds.
    >
    > The neutral, in the event of a fault could become hot and you don't

    want
    > the ground to become hot.
    >
    > >
    > > so my question is, is the inspector gonna have a fit or is this a
    > > common practice?

    >
    > I hope it is not common practice.
    >
    > >
    > > randy

    >
    > --
    > Joseph E. Meehan
    >
    > 26 + 6 = 1 It's Irish Math
    >
    >
    >
    xrongor, Jun 24, 2004
    #4
  5. xrongor

    zxcvbob Guest

    xrongor wrote:
    > just a quick response to whats been posted so far:
    >
    > the box is a fiberglass box hence no ground lug is there, or needed. maybe
    > code calls for a metal box...
    >
    > anyway, ill ask him about it next time i see him.
    >
    > thx
    >
    > randy
    >


    The box has a metal strap (when you take the cover off), and a metal
    screw holding the cover in place (probably recessed so it's inaccessable
    except with a skinny screwdriver.) The metal strap should be grounded,
    but IMHO it's not a big deal because there is no exposed metal when the
    cover is in place. If you *really* want to keep the 3 wire outlet and
    don't want a loose ground wire in there causing trouble, install a
    ground terminal lug on the metal strap -- there's plenty of room for it,
    just screw it to the inside back.

    The right thing to do if you have all 4 wires run already is to rewire
    the dryer for a 4-wire cord.

    If this is a welder outlet we are talking about instead of a dryer,
    there is no neutral connection (the thing that looks like a neutral is a
    ground) and you just tape up the end of the white wire.

    Hope this helps,
    Bob
    zxcvbob, Jun 25, 2004
    #5
  6. xrongor

    xrongor Guest

    "zxcvbob" <> wrote in message
    news:...
    > xrongor wrote:
    > > just a quick response to whats been posted so far:
    > >
    > > the box is a fiberglass box hence no ground lug is there, or needed.

    maybe
    > > code calls for a metal box...
    > >
    > > anyway, ill ask him about it next time i see him.
    > >
    > > thx
    > >
    > > randy
    > >

    >
    > The box has a metal strap (when you take the cover off), and a metal
    > screw holding the cover in place (probably recessed so it's inaccessable
    > except with a skinny screwdriver.) The metal strap should be grounded,
    > but IMHO it's not a big deal because there is no exposed metal when the
    > cover is in place. If you *really* want to keep the 3 wire outlet and
    > don't want a loose ground wire in there causing trouble, install a
    > ground terminal lug on the metal strap -- there's plenty of room for it,
    > just screw it to the inside back.
    >
    > The right thing to do if you have all 4 wires run already is to rewire
    > the dryer for a 4-wire cord.
    >
    > If this is a welder outlet we are talking about instead of a dryer,
    > there is no neutral connection (the thing that looks like a neutral is a
    > ground) and you just tape up the end of the white wire.
    >
    > Hope this helps,


    this is in an unfinished garage/shop, and ya its not for a dryer. just
    general use... heater, welder, whatever. i can see everything clearly.
    there's no metal strap.

    but i think you're getting closer. this isnt a dryer circuit, its a utility
    circuit for garage. he gave me a 10-30R type outlet. and as you say, he
    told me to tape back the white wire and connect the ground to the terminal
    marked white on the outlet.

    but i have all 3 wires + gnd going to the fiberglass box already. maybe i
    should be using a different outlet? which one should i use? or should i
    just use it as is with the third prong a ground and no neutral?

    maybe the simplest way to ask is this. i have all 4 wires going to the box.
    given that, if not a 10-30R wired with no neutral, which type of outlet
    would be the best for a general use shop outlet?

    randy
    xrongor, Jun 25, 2004
    #6
  7. xrongor

    zxcvbob Guest

    xrongor wrote:

    > "zxcvbob" <> wrote in message
    > news:...
    >
    >>xrongor wrote:
    >>
    >>>just a quick response to whats been posted so far:
    >>>
    >>>the box is a fiberglass box hence no ground lug is there, or needed.

    >
    > maybe
    >
    >>>code calls for a metal box...
    >>>
    >>>anyway, ill ask him about it next time i see him.
    >>>
    >>>thx
    >>>
    >>>randy
    >>>

    >>
    >>The box has a metal strap (when you take the cover off), and a metal
    >>screw holding the cover in place (probably recessed so it's inaccessable
    >>except with a skinny screwdriver.) The metal strap should be grounded,
    >>but IMHO it's not a big deal because there is no exposed metal when the
    >>cover is in place. If you *really* want to keep the 3 wire outlet and
    >>don't want a loose ground wire in there causing trouble, install a
    >>ground terminal lug on the metal strap -- there's plenty of room for it,
    >>just screw it to the inside back.
    >>
    >>The right thing to do if you have all 4 wires run already is to rewire
    >>the dryer for a 4-wire cord.
    >>
    >>If this is a welder outlet we are talking about instead of a dryer,
    >>there is no neutral connection (the thing that looks like a neutral is a
    >>ground) and you just tape up the end of the white wire.
    >>
    >>Hope this helps,

    >
    >
    > this is in an unfinished garage/shop, and ya its not for a dryer. just
    > general use... heater, welder, whatever. i can see everything clearly.
    > there's no metal strap.
    >
    > but i think you're getting closer. this isnt a dryer circuit, its a utility
    > circuit for garage. he gave me a 10-30R type outlet. and as you say, he
    > told me to tape back the white wire and connect the ground to the terminal
    > marked white on the outlet.
    >
    > but i have all 3 wires + gnd going to the fiberglass box already. maybe i
    > should be using a different outlet? which one should i use? or should i
    > just use it as is with the third prong a ground and no neutral?
    >
    > maybe the simplest way to ask is this. i have all 4 wires going to the box.
    > given that, if not a 10-30R wired with no neutral, which type of outlet
    > would be the best for a general use shop outlet?
    >
    > randy
    >
    >



    I have a Nema 10-30R outlet for my dryer, and a Nema 6-50R for a welder.
    The metal strap is in the *back*, and it's exposed on the end where
    the cable clamp goes. I don't know if the neutral lug is isolated from
    the metal strap or not (it should be). But back to your outlet -- with
    4 wires I think you should use a 14-30R outlet if this is a 240/120V
    branch circuit. That gives you a choice of a ground or a neutral or
    both by how you cleverly wire the plugs and cords.

    If you are just using the wrong outlet for a pure 240V load because
    10-30's are cheap and readily available but 6-30's are hard to find,
    connect the bare ground wire to the neutral lug and tape up the white
    wire, and only use the third prong as an equipment ground. Heaters and
    welders and 240V air compressors don't need a neutral.

    Bob
    zxcvbob, Jun 25, 2004
    #7
  8. xrongor

    xrongor Guest

    > I have a Nema 10-30R outlet for my dryer, and a Nema 6-50R for a welder.
    > The metal strap is in the *back*, and it's exposed on the end where
    > the cable clamp goes. I don't know if the neutral lug is isolated from
    > the metal strap or not (it should be). But back to your outlet -- with
    > 4 wires I think you should use a 14-30R outlet if this is a 240/120V
    > branch circuit. That gives you a choice of a ground or a neutral or
    > both by how you cleverly wire the plugs and cords.
    >
    > If you are just using the wrong outlet for a pure 240V load because
    > 10-30's are cheap and readily available but 6-30's are hard to find,
    > connect the bare ground wire to the neutral lug and tape up the white
    > wire, and only use the third prong as an equipment ground. Heaters and
    > welders and 240V air compressors don't need a neutral.
    >
    > Bob


    ya ok. thats how he had me wire it up. and thats exactly why i have a
    10-30R. 4 bucks vs something like 11 bucks.

    a guy on the woodworking group also gave me some good advice in that it
    really doesnt matter what i install right now. i got all 4 wires to the
    box, and right now im using the 10-30R as a pure 240V outlet, but if i come
    across something that prefers a different plug or wiring, ill just go get
    one or rewire this one... take about 2 minutes.
    thx
    randy
    xrongor, Jun 25, 2004
    #8

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