I was buy this APC inverter on 2011 in month may 21 from authorised distributors. I was found the voltage started fluctuating like television, water filter, computer etc.
Next day the culprit was the output socket which has burnt and need replacement. The UPS needs frequent manual resets especially when the main voltage is fuctuating.
Another flaw is the UPS keeps overcharging batteries many time upto 16 hours for a nominal black out time is only 3 hour.
I was contact from APC customer care. They are saying the APC service center is not registered. The service center is not able to explain any technical question related to their product. I had been getting high electricity bills for six months.
I woyld not recommed any friend to use this APC inverter