When the battery trouble signal activates because of a low
battery voltage, it indicates that the batteries may have
inadequacies that will prevent the BC-35 from providing the
standby power capacity required to meet national and local
codes. When the signal activates because of a high battery
voltage, it indicates one of the following: 1) BC-35 malfunc-
tion, 2) poor battery terminal connections, or 3) a battery
that has an unacceptable high internal resistance.
It is recommended that the batteries be charged prior to
installation, if necessary. A voltage check of the batteries
should be performed to ensure that the BC-35 charging cir-
cuit will begin charging. Follow Steps 1 and 2 below. Step 2
may also be used to troubleshoot the BC-35 when a trouble
condition is indicated.
Step 1
Test the batteries connected to the BC-35 module.
a. Remove the battery leads.
b. Test the open battery voltage; it should be between
22 and 27 VDC.
c. Reconnect the battery and test it under a load con-
dition. If possible, remove the AC power from the
system and measure the battery voltage. Activate the
audible devices and again measure the battery
voltage. Under both conditions, the minimum
acceptable battery voltage is 21 VDC.
d. If it is not possible to test the batteries as previously
noted, utilize a simulated load. For example, with the
batteries disconnected, a 12 ohm, 50 watt resistor
should be placed momentarily (2-4 seconds) across
the 24 volt battery connections. Measure the battery
voltage under this loaded condition. Again, the
minimum acceptable voltage is 21 VDC.