smart-ups 1400,load indicator is incorrect

[vaillant3388]

my APC smart-ups 1400 is from 1999,works perfect and got new batterys,accepts for the load indicator.
with 450watt is gives only 20% load,only the first load led is burning.
when im going to 900 watts only 3 leds are burning.

so the load measuring electronics are way off,if i want i could seriously overload the ups above its specs....

is the a way to adjust this reading,perhaps with a adjustable resistor somewhere on the board? or to replace some componenent???

i have the tools for soldering,and the ups is not in use of critical stuff,so tweaking is alowed here

 

[josepablomir]

How do you know you have 450 and 900 watts in each instance?
Is the software reporting that value?
Or are you just adding power indications on the loads connected to the UPS?
If you want to be sure you need to get a True RMS Clamp Meter and measure the actual load current and multiply that value by 120V to get the real power requirements of your load (expressed in VA [Volt-Amps]).



___________________________________
Joe
Electro-mechanic Engineering
jpm@ieee.org

 

[rudenate3]

The load indicator is in VA. Could be your not using 450 or 900 VA but less. Those LEDs don't perfectly match up to 20% either... it's like 24% give or take. I would check through the software if you want the most accurate reading. You would want to download Powerchute Business Edition from APC's website. Also, you need the correct serial cable which is a 940-xx24x cable.