Parallel Operation - PROLiNK Master II Series User Manual

11. Operation in Fault mode
1) When the buzzer beeps continuously, it means that there is a fatal error with the UPS. Users can
get the fault code from "DATA LOG" menu. Please refer to the Chapter 4 for details.
2) Please check the loads, wiring, ventilation, mains, battery and so on after the fault occurs. Don't try
to turn on the UPS again before solving the issues. If the problems persist, contact the distributor or
service personnel immediately.
3) In case of an emergency, shut off connections from mains, external battery, and output immediately
to avoid possible damage to the UPS or equipment.
12. Operation in maintenance bypass mode
This operation should only be performed by maintenance personnel or qualified technicians.
When the UPS needs to repair or service and the load could not be shut off, the UPS needs to be put into
maintenance mode.
1) First, switch off the UPS.
2) Then, remove the cover of maintenance bypass switch on the panel.
3) Turn the maintenance switch to "BPS" position.

3-5. Parallel Operation

1. Parallel system initial startup
Please make sure that all of the running UPSs are parallel models and have the same configuration.
1) Turn on each UPS in AC mode respectively (Refer to section 3-4(1)). Then, measure the inverter
output voltage of each phase for each UPS with a multi-meter. Calibrate the inverter output voltage
by configuring inverter voltage adjustment (Refer to SETTING  ADVANCE  SYS PARAMETERS 
VOL CALI screen) in LCD menu until the inverter output voltage difference of each UPS is within 1V
or less.
2) Turn off each UPS (Refer to section 3-4(7.)). Then, follow the wiring procedure in section 2-4.
3) Remove the cover of parallel share current cable port on the UPS, connect each UPS one by one
with the parallel cable and share current cable, and then replace the cover.
4) Turn on the parallel system in AC mode:
a) Turn on the line input breaker of each UPS. If using dual-input unit, please also turn on the
external bypass input breaker. After all UPSs enter into bypass mode, measure the output
voltage between two UPSs for the same phase to make sure the phase sequence is correct. If
these two voltage differences are near to zero, that means all connections are met. Otherwise,
please check if the wirings are connected correctly.
b) Turn on the output breaker of each UPS.
c) Turn on each UPS in turns. After a while, the UPSs should enter into AC mode synchronously
and then, the parallel system is now complete.
5) Turn on the parallel system in Battery mode:
a) Turn on the battery breaker and external output breaker of each UPS.
b) Turn on any UPS. A few seconds later, the UPS will enter into battery mode.
c) Turn on the next UPS in sequence until all the UPSs enter into Battery mode and add to the
parallel system. Now the parallel system is now complete.
If you would like to have more information regarding the parallel operation, please contact
your supplier or service center for detail parallel operation instruction.
2. Add new units into the parallel system
1) You can not add new unit into the parallel system when whole system is running. You must cut off
the load and shutdown the system.
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