I have just bought a new UPS

Everthing appears OK and I have tested it by disconnecting the mains 240v supply and the computer keeps running.

However this morning the computer re-booted when the air-con was turned on.

Any suggestions ?

Need more information here.

Does it reboot EVERY time you turn on the AC ?

Does it do it when you turn the AC off too ?

Are the computer and AC on the same circuit or breaker ?

If so try switching one if it is possible.

Make sure the computer and UPS are on the same power strip.

Let us know these answers and/or if you solve the problem.

To be honest I was scared to try it again in case I had a HD error.

However I have now plucked up the courage to hit the button again and this time......no problem.

Com and AC are probably not on the same breaker.

Sorry cannot be sure as the labels are all in thai but as there are 28 breakers I would assume that each AC has its own breaker.

"Make sure the computer and UPS are on the same power strip."

What ? Sorry you lost me there.

The UPS is plugged into the mains, which then supplies the com.

The AC has not been used for a long time could this have caused it to exert a big start-up drain and hence a voltage drop ?

What concerns me is that the voltage drop was big enough to trip the com but not big enough to trip the UPS. I need it to be the other way around.

Thanks for your help

Your computer should NOT reboot if it is plugged into the UPS. That's the reason you are using a UPS. Low voltage, high voltage or NO voltage will cause the system to use the UPS battery until the problem is corrected.

There are different kinds of UPS's.

If you have a battery based UPS, then the AC should not have caused any problem no matter what the line voltage did. You should be able to run your CPU for several hours or more even during a total power failure for that matter.

It was probably just some anomoly that will not repeat itself.

If it does, then the UPS is faulty and needs to be looked at by a technician.

Power strip comment ...... my bad. Not enough sleep sometimes. 555