Using a UPS with a Gas Generator

Discussion in 'General Electronics Chat' started by demartinoj, Aug 6, 2009.

  1. demartinoj

    Thread Starter Member

    Jan 25, 2009
    Does anyone have any experiance hooking up a UPS in line with a gas generator? I want to use a 2000W gas generator to power some electronics equipment. I am trying to plug a 1500VA UPS in line with the geneartor 120VAC output to condition the output but the UPS indicates there is a problem with the line voltage and switches to battery backup power when connected. I measured the output from the generator to be 124VAC. Anyone have any ideas what could be the problem?
  2. HarveyH42

    Active Member

    Jul 22, 2007
    Is the generator true sine, or modified sine? Probably modified, and might be the source of the problem. I'm assuming your gas generator, is one with a small engine, and not a HHO gas generator...
  3. ifixit

    AAC Fanatic!

    Nov 20, 2008
    The UPS may want to see the neutral bonded to the ground. Neutrals float on some gens. Be sure to ground your system so the computers are grounded for safety and ESD protection.
  4. demartinoj

    Thread Starter Member

    Jan 25, 2009
    I am not sure what you mean by true sine or modified. It is an older industrial type generator and I believe it uses a brushless generator. Small motor. Hence the sine wave is not very clean. Newer generators such as Honda use inverters that produce a very clean sine wave.
  5. Hitzelfritz

    New Member

    Jan 14, 2011
    The previous posters are correct... inexpensive generators make crappy sine waves. Try connecting a substantial inductive load. It will soften the waveform, and may make the UPS happy. I have the same problem. This works for me.