S&C Instruction Sheet 653-506
21
Battery Charging Modes
Two battery charging modes ensure the batteries are kept in proper working condition. Once
a charge cycle of any type begins, the only normal operating mode that can interrupt it is a
Run
event.
Automatic Charge:
The PureWave UPS System uses an automatic charging method to
ensure the system is ready to handle any power disturbances. Battery modules are charged
immediately following a disturbance event. The duration of the charge is directly related to
the magnitude and duration of the event. The batteries are charged for two minutes for each
second of discharge at full load. The battery charger will remain on for one hour after the
batteries are charged.
Equalize Charge:
A complete equalization charge cycle will be automatically performed
every two months. Equalize charging is a battery conditioning function that ensures top
performance of the batteries.
Besides the charging modes noted above, the battery modules may be manually charged.
Manual charging may be required if the PureWave UPS System is not commissioned within
60 days of shipment or if the PureWave UPS System is in the
Bypass
state for more than 60
days. Contact S&C if manual charging is required.
Generator Interface
As an option and if provided, the PureWave UPS System control can be electrically connected
to the transfer switch via a dry contact. Actuating the contact (transfer signal) commands
the transfer switch to start the generator and transfer to the generator (after the generator is
at rated voltage and frequency). The PureWave UPS System will actuate the transfer signal
after the system has been running for 5 to 10 seconds (5 seconds at full load, 10 seconds at
half-load or less).
Following is a sequential listing of events that occur during an outage of more than 5
seconds (assuming full load):
EVENT 1
: Upon a voltage disturbance, the PureWave UPS System goes into the
Run
state.
EVENT 2
: After 5 seconds, the PureWave UPS System actuates the transfer signal to the
transfer switch.
EVENT 3
: The transfer switch sends a start signal to the generator.
EVENT 4
: After the generator is at the rated voltage and frequency (as determined by the
transfer switch), the transfer switch transfers to the generator.
EVENT 5
: The PureWave UPS System "soft" loads the generator.
EVENT 6
: After the generator accepts the load, the PureWave UPS System returns to the
Ready
state.
EVENT 7
: The PureWave UPS System maintains the transfer signal to the transfer switch
until the batteries have charged. After the batteries have charged, the Pure Wave UPS System
will de-actuate the transfer signal.
EVENT 8
: The transfer switch will transfer the load back to the utility after the utility voltage
is restored and all applicable time delays have timed out.
EVENT 9
: The PureWave UPS System will go into the
Run
state while the transfer switch
returns the critical load to the utility.
If the load is at 50% or less of the PureWave UPS System rating, the system will wait for 10
seconds before actuating the transfer signal.
Operation
