[BC] UPS Hell

[Warren Shulz]

In Chicago we have three  UPS stories to log in:

Case 1 - UPS goes to a weekly self test.  Battery bank(14) has a bad one and decides to terminate power to the load as a  result of a bad battery...bank was 14 units of 12 v 70-amp-hr in series.  Entire studio complex is powered down in PM drive after most of the tech staff has left.  Last man standing got access to locked room and operate bypass and then restated 30 PCs to get the train back on track.

Case 2 - A bad battery in an older 5 kva APC for server room cycled into a self test and turned the server PC load on-off hundreds of times as it went in and out of operation.  Happened on a Sunday PM when no staff was about.

Case 3 - You go to do a battery load test and bad cell causes a loss of power and the unit drops the load rather than switch back to AC mains. To prevent this we use a Grainger battery load tester to pretest batteries before doing an on purpose load test.   Battery can be charged, measures 12 v but you put a load on it and its suddenly an open circuit.

With maybe a power blip a year the studio UPS units have caused more problems than they solved.

On the other hand I have one at AM Tx and it has saved the bacon more that 1000 times in its life.

These are all FERUPS Best Technology now APC.  Batteries are not reliable.
Lack of use puts you at risk.  Battery life is 4 yrs.

Warren Shulz
WLS A/F Chicago