2008 MP Power Surge - Anyone Else?

Discussion in 'Mac Pro' started by edpeart, Jan 25, 2008.

  1. edpeart macrumors newbie

    Jan 24, 2008
    Des Moines, IA
    I just got the 2.8 Octo yesterday, and it came with the 2x1gb of Ram. I bought 2x2gb of ram from owc. I installed the new memory right out of the box. When i first started the machine, it blew the breaker in that room. I took out the OWC memory and it worked ok for a while last night. Today, when i woke the machine from sleep, it blew the breaker again. I did several more wake from sleeps, and the lights flicker. Should this thing be using that much juice? I live in a newer condo (2004) and haven't had any other electrical problems. Has anyone else had this problem? What does everyone think, bad Mac Pro?
  2. schreck macrumors regular

    Oct 21, 2007
    New England
    A fellow person living in Iowa! Craziness! (though I'm not Iowan by birth)

    Sounds like an interesting occurrence. I received my Mac Pro on Wednesday and have been using it in a college dormitory without a single problem.
  3. Random Chaos macrumors member

    Jan 16, 2008
    The Mac Pro (excluding monitors) can draw up to 12A. What is your breaker rated at? Most nowdays are 15A.

    I'm running the Mac Pro, 3 LCD monitors, and another PC tower off the same 15A circuit and not having any problems, though I do plan to upgrade it to a 20A circuit just for the two outlets that the system uses. Just in case anyone is planning to make a similar upgrade, 20A requires 12guage wire to the outlets and 15A runs 14gauge...so it's more than just switching out a breaker. In my case, the breaker is in the same room as the computers, so relatively inexpensive. If it's elsewhere in the house, it can be quite pricy.
  4. Blogger macrumors 6502

    Jul 18, 2002
    You'd be better off just running the two different (15 amp) outlets off the two different phases of your panel. Just like any kitchen outlet. Safer, as well, and no need to upgrade the wiring gauge. But you do need to string an extra feed.
  5. Sandock macrumors member

    Aug 10, 2006
    Calgary, Canada
    Just got my Mac Pro last friday, standard configuration.

    I am also experiencing the same thing.

    Anytime I wake the machine, the lights would flicker. The same goes when I start it up.

    I am running it with an APC Back Up UPS XS 1300 plugged in to a regular outlet.

    Is that normal?
  6. faumble macrumors regular

    Jan 8, 2008
    Flicker should be normal, its like when you turn on a vacuum cleaner
  7. newtech macrumors 6502

    Jun 2, 2007
    If that outlet is on a circuit in a sleeping area ( bedroom ) the NEC ( National Electrical Code ) requires it to be protected by an AFCI ( Arc Fault Circuit Interupt ) circuit breaker. AFCI breakers are well known to trip when switching power supplies are in use on the circuit. switching power supplies can cause a signal that mimics the effect of an arc that the Breaker sees as a fault, cuasing it to trip.
  8. bigbird macrumors 6502

    Aug 17, 2007
    No need to run another separate circuit off the other hot bus unless you're using a multiwire shared neutral cc't, which I assume you suggest based on your kitchen countertop reference. You can run a new cc't from whichever bus you want if it's not a shared neutral. You would need 14/3 cable for a 15A shared neutral cc't; 14/2 for a regular 15A cc't.

    PS: I'm an electrician who also can't wait for his dual 2.8 quad w/8800GT!
  9. Blogger macrumors 6502

    Jul 18, 2002
    You are quite right. I was assuming the outlet was 14/2 wire, which would need replacing with 14/3 for a shared neutral or supplementing with another 14/2 run to have 2 outlets in one duplex being fed from both sides of the panel. At least that's the code here in the Great White North.

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