Xenon Pure Sine Wave UPS Review & some Qs

Hi All,

Where I live, power supply is almost like a luxury. Two to three hours outage is a daily occurrence. To deal with it, I have been using two Xenon 1400VA units in my office for the past 8 months.

Xenon Digital Inverters

One unit powers 6 computers & LCDs in our development room (longest I logged was 4.5 hrs of backup during a day long black-out) and the other unit powers the server, two office PCs and 4 tube lights & 3 fans (longest I got out of this was 3 hrs at full load, and more than 5 hrs if I switch off the fans and one PC).

The allowed input voltage range for the units is 180V-260V. If supply voltage drops below or spikes above this range, then the unit switches to battery power. The units are in a corner of my office and everyday I can see (and hear) the units switching back and forth from Mains to Battery at least half a dozen times - so I know that the units are switching to battery when voltage fluctuates.

Each unit is hooked up to two Xenon 130 AH low maintenance batteries. The transfer time from Main supply to Battery supply is less than 10ms (as per their specifications sheet). From experience I can vouch that it is less than 50ms at least. The server PSU is very sensitive to power fluctuations and would reboot if there is more than 50ms interruption in the power-supply. It used to reboot on my old home-UPS, but works fine after moving to the Xenon UPS.

I have been quite satisfied with the performance of these units till now. I paid 24K for each unit (batteries & installation included). I am now expanding my business and adding more computers. Planning to grow up from these small units and go for a 5KVA unit.

I know that the UPS vs power conditioners vs servo stabilizers has been done to death on this forum. I have gone through quite a few of those threads today. So I will just ask two questions for which I couldn't find a straight answer in the previous discussions.

Is the 180V-260V allowed range of the UPS too wide for HiFi equipment - would the equipment get damaged?
Is the <10ms transfer time enough to provide protection from surges and spikes?

Thanks
Teja