[BC] UPS hell

[Dale H. Cook]

At 09:15 AM 2/23/2012, Wayne Fick wrote:

>at first I thought the AC breaker had tripped, the batteries
>had to be at 42 volts for the unit to come alive.

Although it makes sense to me to use a fail-safe relay to connect the load to the mains if the UPS fails, apparently this is not the case in some UPS units which seem to require a minimum voltage from the gel cells in order to function properly. When the gel cell pack is below the minimum I have seen units fail completely - no indicators, no response to controls, no voltage to the load. Replacing the gel cells has restored those units to normal functioning. Replacing the gel cells on a regular basis has prevented further problems in those units.

Dale H. Cook, Market Chief Engineer, Centennial Broadcasting, Roanoke/Lynchburg, VA
http://plymouthcolony.net/starcityeng/index.html