UPS + surge protector?

Discussion in 'Mac Pro' started by malch, May 16, 2012.

  1. malch macrumors 6502

    Jan 20, 2008
    Hi there,
    Experts on this forum advised me a year-and-a-half ago to get a UPS to protect my Mac Pro, and I did (an APC Smart 1500). I've discovered that, for reasons unbeknownst to me, the outlet under my desk is not grounded. An electrician I spoke to said that he could replace the ungrounded outlet with a GFCI outlet, or I could just buy a surge protector.
    I've done a bit of googling, and I found a thread in which someone said that APC advised against plugging the APC UPS into a surge protector because "other, more powerful equipment may draw necessary voltage away from the UPS". But he then pointed out that if there's nothing else connected to the surge protector, then this wouldn't be a worry.
    I'm wondering what my best strategy should be: get a GFCI installed (cost of the receptacle plus cost of electrician) or get a good surge protector?
    Thanks for any advice,
  2. saulinpa macrumors 6502a

    Jun 15, 2008
    What are you trying to solve? The UPS should still work without the ground. Also your UPS already includes a basic built-in surge protector.

    The 3rd (grounding) prong is for safety in case power shorts the case. Surge protectors also use it to shunt spikes. So without the ground your surge protector is only half as good but still functions. A GFCI is a safety device that cuts power when it sees a leak (load and neutral currents not matching) which has nothing to do with surges.

    From the electrician's point of view to fix the outlet properly requires too much work, especially if you have an older house. The shortcut to make it code compliant is that he can change the outlet to a two prong or install a GFCI with a label "no equipment ground." Neither of which helps your computer. Ask him how much to fix the grounding problem. That's the right solution.

    If you still want GFCI/surge then buy something like this and skip the electrician:
  3. philipma1957 macrumors 603


    Apr 13, 2010
    Howell, New Jersey
    pretty much right on spot. I have grounded outlets in two prong homes. you drill a hole in the wall and run a ground wire to a six foot copper ground rod . This can be done via code in your town with an electrician. Now if you can't drop a ground right outside the wall next to the outlet it is more costly.
  4. malch thread starter macrumors 6502

    Jan 20, 2008
    Thanks so much for this detailed information. You know more about this than the electrician I talked to about it (maybe you are an electrician)—he implied that a GFCI would act as a surge protector, which it clearly doesn't.
    Philip, I can't do what you suggest, because my office is on the 2nd floor of my house.
    My house is old, but the funny thing is, all the outlets are three-prong, and all of them are indeed grounded except for this one under my desk. There's a grounded outlet ten feet away. I guess it must mean that whoever updated the wiring (before I moved here) left the old wiring to this outlet only (without realizing that a future owner would be keeping a Mac Pro next to it!).
    Thanks for the advice...
  5. pprior macrumors 65816

    Aug 1, 2007
    a 3 plug outlet that is not grounded is a major safety issue. A surge protector requires a ground and will not work without it (in fact many of the new ones have a warning light and might even beep if not grounded). If you have a grounded outlet nearby (please check to make sure it is actually grounded) then I would fish a new wire to it and complete the circuit, so long as they are on the same circuit. Since there is a wire already going from one to the other, should be easy to do and not sure why the electrician wouldn't have done it. Makes me think the other outlet is not properly grounded either.
  6. westom macrumors regular

    Nov 8, 2009
    Earthing a wall receptacle is a code violation and a safety concern. A receptacle must be safety grounded to the breaker box. Not earth grounded.

    GFCI does not do surge protection for a very long list of reasons. Did he think a millimeters gap inside a GFCI will stop what three miles of sky could not? Any protector that works by stopping or blocking a surge is only protecting from anomalies that are typically not destructive.

    In many older homes, previous owners replaced two prong receptacles with three prong. The safety ground does not exist. You should confirm that safety ground. In some older construction, a three wire connection was made to the first receptacle. Then all other receptacles were only two wire.

    That APC recommendation has it backwards. APC quietly recommends no power strip protector plugged into their UPS. Because UPS voltage in battery backup mode is so 'dirty' as to be potentially harmful. The same 'dirty' UPS voltage is also ideal or sufficient for electronics.

    The superior solution is also the least expensive. Only upgrade breaker box earthing. And earth a 'whole house' protector. Then you have the best protection possible. That works just as well on all two wire and three wire circuits.

    GFCI provides minimal human safety. It does not do transistor safety. It does not do anything to protect a computer.
  7. praktical macrumors regular


    Mar 12, 2012
    Oklahoma City Oklahoma.
    APC quietly recommends no power strip protector plugged into their UPS

    Your statement was well put and on the spot correct. On the issue of not plugging the strip into the UPS I have seen countless times people exercising this methodology to protect their electronics.

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