Liebert 130 kVA - Manual (Page 89)

User Manual
Hipulse - Single Phase ‘1+N’ UPS System 130 kVA - 110V
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8.3.1.2 Switching the system to maintenance bypass from normal operation
WARNING
The internal maintenance bypass must not be used when the UPS
system is comprised of more than two UPS modules in parallel.
Follow the procedure for the single UPS by referring to Chapter 5 – Operating
Instructions: Paragraph 5.4. For a system configured in the “1+N system”, the
changeover from “load on inverter ” to “load on bypass” will occur only when the
operation described in point 3 has been completed on both UPS modules.
8.3.1.3 Switching the system ON from a maintenance power down condition.
Follow the procedure for single UPS, referring to Chapter 5 – Operating Instructions:
Paragraph 5.2 .
8.3.1.4 Switching OFF and isolating one UPS while the other remains in service.
1. In sequence, open the UPS isolators Q4 (output), Q1 (rectifier input), Q2 (bypass
input).
2. Open the circuit-breaker inside the battery cabinet.
To completely isolate the UPS, open the a.c. power supply circuit-breaker (both circuit
breakers if separate supplies are provided for the rectifier and the bypass supply) and
thee output circuit breaker on the power distribution switchboard.
If individual UPS output isolation circuit-breaker (and its auxiliary contacts) are not
installed on the power distribution switchboard, remember that voltage supplied by
the others UPS which remains in service still will be present on the output terminals of
the shutdown UPS.
WARNING
If individual UPS output isolation circuit-breaker are not installed on
the power distribution switchboard, remember that voltage supplied
by the others UPS remains in service will still be present on the output
terminals of the shutdown UPS.
Warning : Wait 5 minutes for the internal d.c. busbar
capacitors to discharge.