Exide Technologies Section 94.40 - Manual (Page 97)

APPENDIX F
93
OPERATING CHARGERS WITH LOAD SHARING
Restore external power connections to both AT30s, and restart according to the normal
procedure in the AT Series Battery Charger Operating and Service Instructions. After the AT30s
restart, the Primary charger attempts to establish communication with the Secondary. If
communication is successful, the chargers behave as follows:
•
The Primary charger displays the message
LS P (Load Share, Primary) on the front panel,
alternating with the normal display of output voltage and current.
•
The Secondary charger displays the message
LS S (Load Share, Secondary) on the front panel,
alternating with the normal display of output voltage and current.
•
The Primary charger controls all voltage settings for both AT30s. You may adjust any voltage
(float, equalize, alarm settings, etc.) at the front panel of the Primary charger. The front panel of
the Secondary charger will not allow any settings to be changed.
•
If one charger loses ac power (or is turned off), the remaining charger returns to independent
operation, whether it was originally the Primary or Secondary. For this reason, it is important to
set up both chargers initially for the same operating voltages. If an alarm condition occurs, both
chargers revert to independent operation for the duration of the alarm.
•
In the event of a fault in the interconnection, or any other problem with communication, the
chargers return to independent operation, and the front panel on each charger displays the
message
E 14, indicating the fault.
•
There is a delay of up to 4 seconds for the two (2) AT30s to establish forced load sharing
communication. If communication is broken (or power is lost for one charger), there is up to a 4
second delay for the other charger to resume independent operation.
•
If you need to interchange the Primary and Secondary chargers, simply reverse the
interconnection cable.
•
The presence of the interconnection cable (and a good interconnection) forces the two (2) AT30s
into load sharing. Controlling load sharing from the front panel is neither necessary nor
possible.
WHEN TEMPERATURE COMPENSATION IS INSTALLED
The AT Series forced load sharing feature is compatible with the external temperature
compensation accessory. It is recommended that each AT30 have a tempco probe, and that the
probes be located as close as possible to each other. When the AT30s are load sharing, the primary
charger will determine the temperature compensated voltage and adjust the output voltage
accordingly. The primary charger and secondary charger will display the set point voltage, not the
temperature compensated output voltage. The voltage displayed by the master and secondary may
be different, if either temperature probe is not installed or defective. A slight difference in the
displayed voltages may also occur if the two probes are not located in close proximity of each other.
TROUBLE SHOOTING
If the AT Series Forced Load Sharing option is installed, but the output currents of the
AT30s are unequal, refer to the following table.
PROBABLE
CAUSE
RECOMMENDED ACTION
1. Connection cable
missing or installed
incorrectly.
2. Incorrect connections
to ac power sources.
3. Defective or improper
Main Control circuit
board A1
1. Ensure that the interconnection signal cable assembly is properly
installed, and that the connector for the
Secondary charger has the
jumper as described at the top of page 3.
2. Ensure that both AT30s are connected to the same ac supply and that
source phase rotation is the same for both chargers.
3. Replace the Main Control circuit board in one charger at a time, noting
system requirements, to restore correct load sharing operation.