Mac Pro power adapter, 2-prong outlet

Discussion in 'Mac Pro' started by bmorris, Apr 27, 2010.

  1. bmorris macrumors 6502


    Nov 8, 2007
    I'm getting a new Mac Pro tomorrow.
    My apartment doesn't have updated 3 prong power outlets.
    I was wondering what the best and safest way to convert the 3 prong mac pro adapter for a 2 prong outlet.
  2. = bluntman = macrumors regular

    Sep 15, 2009
    Toronto, Ontario
    cut off the grounding prong or look around for one of these:

  3. nanofrog macrumors G4

    May 6, 2008
    Are you sure the outlet is actually grounded?

    Ground on such adapters is accessed via the screw that holds the cover to the receptacle, but it's not going to work if the box isn't grounded (i.e. bare copper wire attached to the metal box via a screw in older wiring).
  4. CaptainChunk macrumors 68020


    Apr 16, 2008
    Phoenix, AZ
    My old apartment building (built in 1955) in LA was like that. I must have bought like 10 of those adapters for various electronic gear. But at least they're cheap (about $2 a piece).
  5. nanofrog macrumors G4

    May 6, 2008
    The NEC is updated every 3 years.

    1962 = Ground + Polarized plugs/receptacles on 120V circuits
    1959 = grounded boxes (metal at the time)
    1955 = 120V outlets not grounded (unless local codes preempted the NEC)

    The little adapters will work in that case, but the ground pin isn't actually functional.
  6. lannister80 macrumors 6502


    Apr 7, 2009
    Run a wire out your window connected to the ground pin, shove into dirt.

    Problem solved! :D
  7. nanofrog macrumors G4

    May 6, 2008
    I've run GFCI's that way; drilled a hole, ran a 12AWG wire (20A circuit) outside to a ground rod (house was originally built in 1956). Works quite nicely, and not terribly expensive. :D

    It might not be possible though, if you don't own the dwelling, as you'd need permission of the landlord before doing something like that.
  8. benlee macrumors 65816


    Mar 4, 2007
    Get one of the adapters and then buy a power strip. While the outlet might not actually be grounded, you are still decently protected.
  9. jleffell macrumors member

    Jun 8, 2009
    So plugging the MP into a surge protector that is plugged into a non-grounded 3-2 pin adapter is ok despite the fact that its not grounded? I don't understand how this will offer any benefit above plugging the MP directly into the adapter?

    I just moved into a crappy apartment (built 1962) and none of the outlets other than the bathrooms and kitchen are grounded. The manager says that they aren't required to ground the outlets bc they are grandfathered in. I'm hoping that's not true and I can file a complain with the city. I had never lived anywhere without the three pronged outlets and thus never thought to ask prior to signing the lease (they didn't show us an example apartment and I doubt I would have realized to check).

    I really need a solution. Thanks.
  10. bmorris thread starter macrumors 6502


    Nov 8, 2007
    i'd try to complain.
    some of mine are and some aren't.
    so my landlord is fixing some 2 prongs to 3.
  11. slughead macrumors 68040


    Apr 28, 2004
    You REALLY want a ground when working with a computer, especially an expensive one.


    Many 2 -> 3 prong adapters have this little metal tab on it. Wrap a wire around that and find a ground somewhere.

    I haven't read the whole thread, sorry if this is redundant
  12. Unique Visuals macrumors regular

    Mar 17, 2007
    In the woods
    No Ground, no way

    Theres no way I would run without a ground. Even using a power strip will offer little help. No ground then no place to dump that extra power. It only takes one surge or lighting strike on the system. If you can't get it out a window or other opening I would use a 14 to 12 Ga. solid wire along a baseboard and to the closest water pipe. They make clamps just for that. If you use an adaptor, I would make sure it has a real good connection and not just wrapped around an eyelet.

    I wired in Isolated Ground outlets for all my electronics. Each outlet has a separate ground to a 8 foot grounding rod. I use APC backup units for my comps. We get a lot of lighting storms here and 20+ years I've never had a problem with comps. I can't always get to them to shut them off in time, otherwise three run 24/7

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