Dear sir I have Powerware 9120 UPS since Jan-2007 to till now but yesterday it was getting problem and LCD show SITE FAULT Error what is meaning of that and why it occor and what is sholution. now it is working fine but it would be posibile that this error will be occor sadanly in future, and my job/working will remain in panding, i want to fix this error

If UPS is displaying "Site Fault", it is doing its job correctly. You need to check the wall receptacle. Probably hot and neutral reversed, or the neutral and ground are reversed, by whom ever installed the wall receptacle. You need to have the plug-in for the UPS intact, i.e. the ground pin must not have been cut off. If an extension cord connects the UPS to the wall, thge cord must be working correctly.

Site fault = Live and Neutral connected wrong way round (polarity) OR Too much voltage between Neutral and Earth.

Solution: Check line and Neutral connections + Settings-Site fault test-disable (ship use etc)

Hope this helps.