Input Voltage too HIGH

[mpdickinson]

Hi,

I have a number of computers attached to a UPS, which is only at 30% load. The problem seems to be the input voltage, it keeps saying that it is too high.

It fluctuates during the day and stays at around 240-245 then at night it goes up and down between 240-255.

Everytime I get an email from my UPS saying it has had a frequent overvoltage so it trims it down(Its highest setting is 253V)... surely this will cause me problems eventually.

Anyone have a solution on what to do to stabilised it?

Kind Regards

Mark

 

[waross]

This sounds like over-kill for a few computers but it may be wise to have your supply transformers set down a tap. That would put your daytime voltage at 234-241 volts and the nightime voltage at 234-246. Now your voltage range is 100% to 106.25%. Dropping the voltage 2.5% will give you a voltage range of 97.5% to about 103.6%.
It may even save you some money on your power costs. Incandescent lighting and resistance will use less power.
If this approach is not feasible, you can use a bucking transformer to drop the voltage a little. You need a transformer with a 240 volt primary, and a 6 volt secondary. The transformer should be rated for buck-boost service.
The third approach is to add a voltage regulator ahead of the UPS.
yours

 

[TheBlacksmith]

I had the same problem over 20 years ago; daily peaks were blowing out power supplies in a military training simulater almost daily. Our particular transformer required "raising" the input voltage taps, which had the effect of dropping the output 15 volts. Easy 30 minute fix with all safety precautions - no more blown power supplies.