Power Supply blew house fuse

Hey guys the other night I just finished upgrading my computer and I changed the power supply from 750w to 1200w because I'm adding a lot more such as a second graphics card. The new power supply is a cooler master 1200w silent pro gold. However when I turned the power on for the first time the fuse in my house blew. Fixed up the fuse then tried another socket where I have tried before and blew the fuse again. I have tried this socket before with my old psu it works fine. Anyone know what could be the problem? It's 42 degrees and I have no aircon now because my fuse is fkd.

thanks guys
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  1. Sounds like you don't have a fuse capable of 1.2MW, so you'll need to get someone in to wire up a fuse that can handle that kind of load, or go with a lesser PSU. It is also at least possible that the PSU is defective in some way, and exchanging it would certainly be cheaper and easier than getting an electrician in to fiddle with a circuit.
  2. You don't need close to 1200 watts with anything short of 3 x GTX 680 or HD 7970s. In fact a 1250w power supply is recommended for a 4 x GTX 680 setup.

    http://www.realhardtechx.com/index_archivos/Page362.htm

    750 watts is sufficient for almost any dual GPU setup at least with current generation cards.
  3. House+Trance said:
    Hey guys the other night I just finished upgrading my computer and I changed the power supply from 750w to 1200w because I'm adding a lot more such as a second graphics card. The new power supply is a cooler master 1200w silent pro gold. However when I turned the power on for the first time the fuse in my house blew. Fixed up the fuse then tried another socket where I have tried before and blew the fuse again. I have tried this socket before with my old psu it works fine. Anyone know what could be the problem? It's 42 degrees and I have no aircon now because my fuse is fkd.

    thanks guys


    Hi - agree with anort on how much psu watts/amps you need.

    Since the PSU only pulls from the wall the demand placed by
    your pc compononts, then the 1200w is not the problem.
    It could still be the psu however.


    You either have a bad psu, or another electrical problem. Prob
    need to try another psu as a 1st step.
  4. The PSU's caps and coils aren't charged yet so the intial power-on will draw quite a bit...fwiw.
    I'm not surprised you popped the fuse/breaker but I wonder what else is on that circuit? Did anything else go out? odds are several things did.
  5. Being that he is in a house with fuses and not a circuit breaker it has to be 1950s or older. I can't think the power in a house that old will be very clean either so he will probably need a good UPS or line conditioner. Still my earlier post holds true. 1200 watts is very likely crazy overkill. At least he managed to pick one of the only Coolermaster models that's not junk.
  6. popatim said:
    The PSU's caps and coils aren't charged yet so the intial power-on will draw quite a bit...fwiw.
    I'm not surprised you popped the fuse/breaker but I wonder what else is on that circuit? Did anything else go out? odds are several things did.



    Thanx for the initial power on note - confess I didn't think of it.
  7. anort3 said:
    Being that he is in a house with fuses and not a circuit breaker it has to be 1950s or older. I can't think the power in a house that old will be very clean either so he will probably need a good UPS or line conditioner. Still my earlier post holds true. 1200 watts is very likely crazy overkill. At least he managed to pick one of the only Coolermaster models that's not junk.



    Brings back memories of running down to the cellar to change fuses - UGH!
  8. Thanks guys yeh pretty sure it has something to do with the psu because my vacuum cleaner runs 1600w and that's fine. I'm getting it tested today anyway il let you know.
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