Xtreme Power Conversion Corporation
E90 Service Manual
Page 58
Uninterruptible Power Supply
Parallel system commissioning
Warning: When UPS is working, the internal Bus capacitor stores a lot of energy. But isolated with mains cannot
guarantee completely no electricity inside the UPS and need extra attention when do the maintenance. When
cut off all the external input power supplied for maintenance, use the bleed resistor to release the energy stored
in Bus capacitor after open the case firstly to avoid causing injury to persons.
Please refer to the “UPS repair/maintenance”, especially the “Security maintenance conditions” and “ Close-
Disassembly/Reassembly UPS”.
Parallel system should be commissioning when the stand-alone are all intact.
Parallel system should be commissioning when the stand-alone are all intact.
Take 4 units in parallel for example.
1) Confirm the input/output wires connection and input phase sequence are correct; switch off the battery
breaker, and measure the +/- bat voltage of all battery group are normal.
2) Connect the parallel cable, it should be formed loop connection
3) Switch on the input breaker of unit 1,and access LCD setting interface to setting the working mode ID parallel
number redundant number. Require setting the in series number capacity of battery. The output voltage level
and Bypass protection range are default setting.
4) Turn off the input breaker of Unit 1, and make sure the UPS is off. Turn on the input breaker of Unit 2,access
the LCD setting interface, setting the parallel working mode, ID NO.2, parallel 4 units, redundant number .The
other setting are the same as UPS 1 operation.
5) For Unit 3 and Unit 4 UPS, the operation setting are all the same as Unit 1 and 2.
6) Turn on Bypass/input/output breaker of all the paralleled UPS, then confirm all the setting are correct. Each
UPS has their owed different ID.
7) Turn on all the battery breaker and confirm the parameter (V/I) are normal.
8) Connected the Load, and check whether the output current are balance.
Switch on and off the utility breaker to test all the UPS converters system from Utility to battery and restored
function are working find
Shutdown steps
1) Confirm the load information to avoid overload when turn off single unit;
2) Shut down each UPS according to the stand-alone UPS shutdown steps.
Emergency shutdown
Connect all the EPO ports to a key switch according to the following figure. When emergency occurs, switch on
the key can turn off all the outputs of UPS in this parallel system.