APC UPS 750 ES

[Anonymous user]

I bought a new APC brand battery for my 750 ES that I have been having issues with a and it looks like it maybe working better now.

I am still in the testing phase and I connected a lamp with a 60W incandescent bulb to it.  When I turn it on it says it only has a 22 watt load.

Is there a way to fix this to re-calibrate the load on the UPS because it is obviously wrong.

I plugged in other items that I know the load of and it is always way under on the true load.

Joe

[BillP]

Hi Joe,

The Back-UPS ES 750G / BE750G is a Stand-By UPS. Being that it's Stand-by it can not truly provide accurate load capacity, unless it is operating off the inverter. The load provided while online is only approximate. To see the true load, the UPS should be forced to battery.

Now that being said, depending upon the age of the incandescent light bulb your using you may discover it's not drawing the full specified watt rating. As these bulbs age, the filament is depleted through continuous use resulting in diminished current draw and overall luminance.

Secret Squirrel

[Anonymous user]

Thanks.

Looks like the investor had failed. On battery I am only getting 85v. 

[BillP]

That may be due to the type of voltmeter you are using.

The UPS produces a step approximated sine wave which can not be accurately measured by a standard voltmeter. These inexpensive meters are often refereed to as Non-True RMS voltmeters which are widely available at any local hardware / automotive store. These meters are only capable of averaging their reading.

When measuring a Pure Sine wave, the True RMS and Non-True RMS meters will give the correct AC reading, however when measuring any waveform other than the Pure Sine wave, the Non-True RMA meter provide a voltage reading much lower than what is present. In some cases it could be as low as 40%.

A True RMS meter will actually have this printed somewhere on the enclosure, unlike a Non-True RMS.

Secret Squirrel

[Anonymous user]

I used a fluke true one. 

I also thought it was wrong when the 60w bulb from an incandescent light I had plugged in for a test load was dim when running off battery but bright when I plugged the ups back in. 

[BillP]

Are you measuring between Neutral and Hot while on battery?

[Anonymous user · Accepted solution]

I am getting the 85 v on plug. When on battery. Plus lights are dim when on battery. Lights go bright and I get 115v when I go back and plug in ups.