Checking The Voltage Of A Battery Box Or A Battery Pack - HP PowerTrust A3589A Manual

Troubleshooting

Checking the Voltage of a Battery Box or a Battery Pack

Checking the Voltage of a Battery Box or a Battery
Pack
WARNING The following procedure should be performed by qualified service
personnel only.
The battery packs in the Battery Box are connected in series-parallel; that is, the five
packs at the front and the five packs at the back are in parallel, and each of the two groups
of five battery packs is connected in series with the other group of five. Thus, while the
voltage of a single battery pack is nominally 27 V, the total voltage at the output connector
of the UPS Battery Box is nominally 54 V. A battery can lose its charge however, and when
it does, UPS problems can develop.
Some of the troubleshooting procedures listed in this chapter recommend that the
batteries be tested to determine if they are serviceable. There are two batteries in a
battery pack. While you cannot check the voltage of a single battery, you can check the
voltage of a battery pack. You can also check the voltage of the Battery Box at the cable
connector of the Battery Box. Use the following table to determine what action to take
after you check the voltage of a battery pack or the Battery Box. Refer to column one if you
check the total voltage of the UPS Battery Box, or column two if you check a single battery
pack.
Battery Battery
Box
Voltage Voltage
below 39V below 19.5V
1
above 48V above 24V
39V - 48V 19.5V - 24V
1. The voltage from the Battery Box could measure 48V even with several defec-
tive battery packs. The result could be a lower than expected hold-up time. If
you suspect a battery problem, it is recommended that each battery pack be
checked for the correct voltage and/or a blown fuse.
6-4
Pack Battery Condition and Action Required
The battery is faulty and should be replaced.
The battery is charged and should not be replaced.
The battery may be faulty. To determine if it needs to be
replaced:
1. Restart the UPS and let it charge the batteries for at
least 14.5 hours.
2. Recheck the battery voltage.
Chapter 6