20 - 80 kVA parallel UPS systems
User’s and Installation Manual
1018390
Revision C
39
2.
Check that the optional system bypass switch is in the ‘BYPASS’ position, and the
individual service switches are in the ON position.
If the system configuration does not include the external system bypass switch, the
critical load must be disconnected, (when cold battery start) or UPS modules must be
started immediately after each one (during 30 seconds) to prevent overload situation
at the system start-up.
3.
Start UPS modules one by one:
- Check that the output breaker S2 has not been tripped by resetting it to the ON
position.
- Turn on the main breaker F1 and battery circuit breaker F2 to the ‘ON’ position.
- Turn on the circuit breaker F4 (20/30 kVA UPS modules with ext. BAT cabinets) to
the ‘ON’ position.
4.
Start the UPS module by turning the main switch S1 to the ‘ON’ position.
5.
Check that the UPS module has started:
- Green UPS ON led is lit if mains power is available (normal start)
- Yellow BATTERY led is lit if the battery power is available (cold-start).
6.
Check that yellow BYPASS led (contact signal of the system bypass switch is ok) is lit
in the front panel.
7.
Repeated sections 3 through 6 until all UPS modules have started.
8.
Check that service switches of the SPM9305 (or local tie panel) are in the ‘ON’
position.
9.
Transfer the critical load to UPS modules by turning the system bypass switch to ‘UPS’
position.
8.3 Operating system bypass switch
The system bypass switch is used to bypass the parallel system during maintenance or
servicing. Maintenance bypass switch is located on the front panel of the optional SPM9305
cabinet. Using the switch does not cause any break in the output voltage, if the input voltage
and frequency are accepted and the system is synchronised to the input mains.
The parallel module includes a mechanical bypass switch S51 (Make-Before-Break type) and
four maintenance switches S11, S21, S31, and S41 for disconnecting the outputs of UPS
modules during maintenance or service.
The maintenance bypass switch has the following positions:
•
‘I’ or ‘UPS’ normal position, the load is supplied from the UPS modules.
•
‘I+II’ or ‘UPS + BYPASS’ position, the load is supplied from UPS modules (internal bypass
mode) and the system bypass in parallel.
•
‘II’ or ‘BYPASS’ position, the UPS modules are bypassed and the critical load is supplied
from the system bypass power line.
If the system bypass switch needs to be used it is recommended to check that the bypass
input power is connected and present in the SPM9305 cabinet. The switch is used only on
rare occasions and the procedure is following:
