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We have a POWERWARE 9120 UPS system not working with error message :Powerware 9120 DC Bus Fault Problem.We have replaced all the batteries inside the UPS ,how do we do with this repairs ?.

Posted by SETLAK on

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  • Hasnat Muneer
    Hasnat Muneer Sep 24, 2016

    My dear its not battry fault

  • Hasnat Muneer
    Hasnat Muneer Sep 24, 2016

    its related about pfc

    SETLAK Sep 24, 2016

    pfc means wha ?.. kindly sir explain



1 Related Answer

SOURCE: Powerware 9120 DC Bus Fault Problem.

there is a 100uf/63v capacitor near the IRF630 fet. You need to replace this in order to fix this error. Along there is also a 2200uf/16v capacitor. It is a good idea to change the both at the same time.

Posted on Feb 05, 2008


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You can download the manual and other literature at

The contacts for support in India are found at

They offer a battery monitoring software package, at

You can email support at
Good luck

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