Exide Technologies JA5009-00 - Manual (Page 17)

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2. CURRENT LIMIT RESPONSE AND ADJUSTMENT
a. Checks and Adjustments: Make certain the charger leads are connected to the battery and that
the panel voltmeter indicates the proper polarity. Switch the DC breaker (CB2) to "ON" and AC breaker
(CB1) to "ON". The "AC ON" indicating light (DS1) should illuminate, indicating power has been
applied. With the charger in float mode, a float voltage charge should be indicated on the panel
voltmeter and the ammeter should show either a charge current, or practically none at all, depending on
the state of battery charge.
1. If the batteries are in a discharged condition, switching to the equalize mode will cause the
charger to automatically go into a current limit condition. If, however, the batteries are fully charged they
probably will not draw current in the current limit range. In order to cause this condition, it will be
necessary to connect additional load to the battery charger or battery bank. This can be resistive elements
or turning on the normal load of the installation. When current limiting is encountered, observe that the
charger voltage will be reduced below its set value by the current limit feedback signal. Observe that as
the current limit condition continues, the voltage will slowly increase as the batteries take on a charge.
Eventually the current will begin to decrease below the current limit value and continue to decrease to a
value less than 100% of rated output current. As the current decreases below 100% of rated output
current, the voltage will become constant at the equalize value and remain so.
2. To check the system response, turn the AC breaker (CB1) to "OFF" to simulate line voltage
failure. Charging current will return to zero on the instrument panel ammeter (M1), and the voltage
should reduce slightly. Place a load on the battery and discharge it heavily for a short period of time until
the voltmeter drops to float value or slightly lower. Return the AC breaker (CB1) to "ON" and observe
that charge ammeter again reads 110% of charge rate and voltage is less than the equalizing level. If
current is greater than, or less than 110% of rated charge, open the cabinet and locate the CURRENT
LIMIT potentiometer on the control trigger PC board (A1). Reference the component layout on page 29
and schematic on page 30. The CURRENT LIMIT is labeled R11 on single-phase control PC boards
(GK0058) and R65 on three-phase control PC boards (GK0048). Adjust this control for 110% charge
current. Repeat the AC circuit breaker (CB1) ON-OFF sequence listed above. If charge rate is still 110%
rated value for which it was set, close the cabinet. Restore the charger to float mode.
b. Checks to Make if Malfunctioning: If all of the above adjustments were attempted and a high
current persists, the current limit circuit on the control trigger board or the ammeter or shunt used for
current sense may be defective. The interconnecting wiring may also be faulty. Make the following
checks to isolate the fault.
1. Turn the current limit control on the control trigger PC Board (A1) to determine if it has any
effect on the high output current reading. This control is the potentiometer labeled R11 on single-phase
control PC boards (GK0058) and R65 on three-phase control PC boards (GK0048). If it does have an
effect, make the adjustment for 110% rated current for a current limit setting as described in paragraph
IV, 2, a, 2 above.
2. If no effect is noted, IC1 on the control trigger PC board (A1) may be defective. If so, replace.
3. Check the voltage generated across the ammeter (M1), or ammeter shunt (SH1) to determine
that sufficient voltage is available at rated current to activate the current-limit feedback amplifier. See
Section III, 2, h. Use a sensitive DC voltmeter and measure the voltage across the ammeter (M1) or
ammeter shunt (SH1). Measure the voltage from the "current limit" pin to the "control circuit reference"
pin, on the plug (SO1) of the control trigger PC board (A1). These pins are respectively pins #1 and #10
on single-phase control boards (GK0058) and pins #6 and #9 on three-phase control boards (GK0048). If
the sense voltage is not present at the control trigger PC board (A1), check the wiring. If the wiring is
satisfactory, proceed with the check sequence listed in Table A trouble shooting chart on page 27.