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S&C Instruction Sheet 653-502
Operation
Battery Charging
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 inter-
rupt it is a Run event. The batteries can also be manually charged if they are being stored
before installation.
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.
Manual Charge:
If the battery modules are to be stored after shipment, they must be
stored in a cool place (50°F-60°F/10°C-16°C). Manual charging may be required if the
system is not commissioned within 30 days of shipment or if the system is in the
Bypass
state for more than 30 days. Contact S&C Electric Company to make arrangements for a
service visit to perform the maintenance charge.
Generator Interface
As an option and if provided, the Pure Wave UPS System control can be electrically con-
nected 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 sequence of events listing the events that occur during an outage of more
than 5 seconds (assuming full load):
STEP 1.
Upon a voltage disturbance, the PureWave UPS System goes into the
Run
state.
STEP 2.
After 5 seconds, the PureWave UPS System actuates the transfer signal to the
transfer switch.
STEP 3.
The transfer switch sends a start signal to the generator.
STEP 4.
After the generator is at the rated voltage and frequency (as determined by the
transfer switch), the transfer switch transfers to the generator.
STEP 5.
The PureWave UPS System “soft” loads the generator.
STEP 6.
After the generator accepts the load, the PureWave UPS System returns to the
Ready
state.
STEP 7.
The PureWave UPS System maintains the transfer signal to the transfer switch
until the batteries have charged. After the batteries have charged, the PureWave
UPS System will de-actuate the transfer signal.
STEP 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.
STEP 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.
