INSTRUCTION / TROUBLESHOOTING MANUAL FOR MODEL A75M
PAGE 5 OF 13
THEORY OF OPERATION & INDICATORS
FRONT PANEL
The panel has a digital display, meter select/equalize (EQ) momentary switch, on/off switch and eight (8) LED
lamps.
The digital display indicates Output Amps, Output Voltage, Ampere Hours Returned, and Elapsed Time Charging
and Cooling Time (elapsed time from end of charge).
A "Meter Select
”
switch and associated indicator lights allow you to read any one of the four (4) operating
parameters on the digital display. After powering up the unit and connecting the battery, the digital display
indicates the output amperage of the charger. Press the "Select
”
switch down once and the "Output Voltage"
will be displayed. Press the "Select
”
switch down a second time and the "Amp Hours Returned" will be
displayed, a third time and the "Elapsed Time Charging" will be displayed.
NOTE: The Charger must be charging the battery for 1 minute to obtain this reading; the amp hours are
updated every minute. A third push of the button shows the elapsed charging time in hours/minutes.
A "EQ
”
switch when pressed up allows the charger to charge six (6) additional hours after the 80% charge is
reached.
NOTE:
The equalize switch can also be used to start the charger even if a battery is discharged below 1.6 Vpc.
Caution must be used when using this feature to start the charger because the initial battery voltage sensing is
being disabled and the wrong battery could be being connected.
An "On/Off
”
switch allows you to turn off the charger when disconnecting the battery during the charge cycle.
(The on/off switch must be placed back to the "ON" position after the battery is disconnected to activate the
automatic start function.)
The lamps are as follows:
* "On Charge" Lamp
This indicates after the charger has successfully completed the autostart cycle and the input contactor has
closed.
* "80%/Complete" Lamp
This (LED) indicator will flash when the battery voltage reaches 2.40 volts per cell. This means the battery is
80% charged. The 3 (normal) or 6 (equalize) hour timer is activated. At the end of the charge cycle this LED
indicator will be on solid, the display will display amp hours returned (when the amp hour LED is on), Elapsed
time of charge cycle (when the elapsed time LED is on), and the time from charge complete (cooling time) 80%
complete light on.
* "Equalize" Lamp
Lamp indicates when the equalize mode is activated by the equalize switch.
* "Failure" Lamp
The "FAILURE
”
lamp is a summary alarm. When the failure light illuminates, the number on the digital display
indicates the type of failure. See below:
AC voltage failure
0001 12 hour override timer time out.
0004
Wrong size battery (cells) or Low Battery
Voltage - See Note**
0003 High DC current/voltage
0005
Unit will shut off within 15 minutes if a fully
charged battery is connected to charger
0007
**NOTE: To disable this feature, push the Equalize button. The unit will start. Make sure a battery with the
correct number of cells is connected to the charger.
