UPS dummy battery bank

[hallmg]

Hi,

I am looking to acquire some kind of dummy battery bank which could be connected to a UPS charger load, while the main bank is disconnected and put on on discharge test, would it be a case of making something up or could there be something available off the shelf?

Any help would be much appreciated.

hallmg.

 

[DanEE]

Not enough information in your post to know what your requirements are... but the following is an example of what was done for a customer that required quarterly discharge tests to be done.

For this relatively small sized system, we brought to the site and connected in a series string of four 12V 70AH batteries (large enough for the purpose stated below) first, paralleled in with the main 48v battery string and then disconnected the main battery string for the discharge test.

The purpose of the 48v string of four 12v 70AH batteries was to keep the UPS operational to provide backup power in the event a power disruption occurred while we were performing the discharge test. While the 12V string would not keep the UPS up for very long, it would give us sufficient time to get the main string connected back up for a longer run time.

The above procedure was done by people experienced and trained using insulated tools, (and insulating any adjacent grounded metal) to make the hot connections in a safe manner.

Other customers have had the requirement (and would be more suited to larger capacity systems) that their UPS installations have dual (and in a few cases triple) strings of batteries with the ability to switch out strings (e.g. for battery replacement, testing purposes and for redundancy in the event a string of batteries were to fail.)

 

[GroovyGuy]

Howdy hallmg,
What size are we talking about here (ie in Volts and Amps). I suspect that you do not have a static-transfer-switch on the inverter output, correct?

Why not do the discharge test on-line? ie turn off the rectifier, but leave the inverter on. Measure the amp-hours and voltage, voila a poor man's discharge test. This may not be as sophisticated as a bench-type discharge test, but it will certainly give you a pass/fail on the batteries (with very little effort and risk).

The (5-30kVA) UPSs that I have bought over the last several years;
- have the ability to disconnect/replace the battery and continue to operate
- have a built-in discharge test capability
- have a static bypass transfer-switch on the output

Regards,
GG

"Wish I didn't know now what I didn't know then." -- Bob Seger