Exide Technologies Section 93.30 - Manual (Page 25)

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19. COMBINED ALARM STATUS MONITOR "CASM" PC BOARD ASSEMBLY (EJ0837)
Note: Refer to the Drawing (EJ0837-XX) on page 49 for additional information.
Purpose: The Combined Alarm-Status Monitor (CASM) provides a comprehensive, cost-effective
method to monitor the integrity of the battery charger and the dc bus.
Description: The CASM combines the monitoring and alarm functions of the High-Low AC Voltage
Alarm, High-Low DC Voltage Alarm, Ground Detection Relay Alarm, Charger Failure Alarm, and a
Common Alarm Relay into one printed circuit board assembly (A24). Each alarm in the CASM PC board
operates similarly to the alarms in the equivalent stand-alone option (see previous descriptions).
One or two form-C relay contacts are provided for each alarm function. These contacts (TB15-1 thru 18)
have a contact rating of 0.5A, 125 VAC/VDC resistive. Panel indicators (DS26-DS32) are provided for each
alarm function except the Common Alarm. In addition, a front-panel push-to-test switch (SW20) checks the
front panel indicators. SW20 tests only the CASM indicators. All relays reset automatically when the alarm
condition is corrected. All alarm relays have a 15 second time delay, except the Charger Failure Alarm.
You may operate the CASM Charger Failure Alarm in either of two modes:
1) True Charger Failure Alarm: In the True Charger Failure mode, the CASM PC board does not
report an alarm when the charger output current is zero, unless the charger actually has failed. The CASM
performs a periodic self-test to accomplish this.
2) Zero Current Alarm: In the Zero Current mode, the CASM reports an alarm whenever the charger
output current decreases to zero. In this mode, you may get false alarms if your normal load is very low, or if
you have two chargers connected in parallel.
To change the Charger Failure Alarm mode, set the switch (SW1) on A24 to the desired mode. To
change the interval of the self-test in True Charger Failure mode, move jumper (J11) on A24 to the desired
position (4 minutes or 8.5 minutes).
You can remove the Charger Failure Alarm from the Common Alarm circuit by moving jumper (J6) to
pins 2-3. This reduces the incidence of false common alarms, if your system has little or no continuous load
current, and you chose the Zero Current mode. This does not affect the operation of the Charger Failure
Alarm relay or panel indicator (DS30).
Installation: Remove the mating plug from the alarm terminal block (TB15). Wire remote alarm
indicators to contacts 1-18 on TB15 according to drawing EJ0837-XX. If you ordered two form-C contacts,
wire both plugs (TB15A & TB15B) according to the drawing. Be sure that your monitor, or other load, does
not exceed the relay contact rating on TB15.
Optional Wiring: The standard alarm terminal block
(TB15) supplied on the CASM features solder-less plug-in
terminals, accepting #18-14 AWG. wire. An optional
auxiliary alarm contact terminal block (TB15-AUX) or
blocks (TB15A-AUX & TB15B-AUX) may be supplied
external to the CASM PC Board assembly (A24). TB15-
AUX is supplied if the customer's remote alarm wiring
requirements exceed the specifications of the standard
terminal block (TB15). Contacts 1-18 on TB15-AUX are
wired directly to contacts 1-18 of TB15 on A24. TB15-
AUX terminal blocks feature 6-32 binder head screw
terminals, and will accept #22-16 AWG. wire.
If you have a grounded battery, disable the Ground Detection Alarm circuit by moving jumper (J7) to
pins 1-2, and by removing wire # 836/GR from R107 to “CHASSIS GROUND” (see EJ0837-XX). Putting
J7 on pins 2-3 enables the Ground Detection Alarm circuit.