5: Maintenance
5-8
PRC-PS-MS
Float Charge
Voltage
This section assumes a failure in the
Float Charge Voltage section on page
if the float charge voltage is out of specification. The float charge voltage
should be 13.3 Vdc.
1. R19 (20 k
ohm) and R22 (100 k
ohm) are 1% resistors that form a
voltage divider that sets the float charge voltage. Turn the PRC-PS off
(remove the AC power cable) and measure the resistance of these
resistors to verify they are within 5% of their stated value.
2. Turn the PRC-PS on and verify that the float charge voltage is within
specification (13.3 Vdc). If it is significantly out of specification, refer to
the Current Source section (step 8) on page 5-7.
Reset Function
This section assumes a failure in the
Reset Circuit Check section on page 5-3
if the DC voltage does not drop when pressing the RESET button. Turn the
PRC-PS on for the following checks.
1. On the IC, measure the DC voltage on pin 3. Press and hold the RESET
button and observe that the voltage drops to 0 Vdc.
2. If the voltage does not drop, inspect the RESET switch and associated
wiring.
Overcharge
Voltage
This section assumes a failure in the
Overcharge Voltage Check section on
if the overcharge voltage is not set at 14.0 Vdc. Turn the PRC-PS on
for the following checks.
1. R19 (20 k
ohms), R22 (100 k
ohms) and R18 (330 k ohms) are 1%
resistors that set the overcharge voltage. Turn the PRC-PS off (remove
the AC power cable) and measure the resistance of these resistors to
verify they are within 5% of their stated value.
2. Turn the PRC-PS on and verify that the overcharge voltage is within
specification (it should be 14.0 Vdc).
Undervoltage
Protection
This section assumes a failure in the
Undervoltage Protection Circuit Check
in the test procedure if the FAULT LED does not light
when an under-voltage condition (possible shorted battery cell) exists. Turn
the PRC-PS on for the following checks.
1. If no status LEDs are lit,
refer to the Status LEDs section on page 5-10
,
also refer to the Current Source section (step 5) on page 5-7.
Reverse Current
Protection
This section assumes a failure in the
Reverse Current Protection section on
if diode D1 fails to provide reverse-current protection. Turn the
PRC-PS off for the following checks.
