OPTI-UPS DS160KD33 - Manual (Page 52)

4-3
(b) Open the battery breaker – If you want to shutdown all the power of the
UPS, continue to open the battery breaker. Now the DC bus is
only supported by the rectifier.
(c) Open the rectifier breaker – Open the rectifier breaker will then further
take the power source away from the DC bus; therefore the DC
bus will start to drop slowly. After 5 min., the DC bus will drop to
a safe level (let say 20VDC).
(d) Open the reserve breaker – Before opening the reserve breaker, there is
power exists at the output, but after opening the reserve breaker,
the output (or load) will no longer have power supply now.
Therefore, before opening the reserve breaker must make sure
there is no critical load connected to the output.
(e) At last all power has been cut off now, there should none of the LED or
LCD lit. The UPS now is completely shut off.
4.3. From Inverter to Bypass Procedure
If you want to stop the UPS for maintenance and do not stop the power supply
from the load, you can follow the steps below to turn the UPS to maintenance
bypass mode without interrupting the output power supply. (But this procedure is
for standard system, 380/220V 3 phases 4 wires Input, 10~160KVA. For special
specification and those above 160KVA, please refer to the brief instruction label
stuck in front of the PCB holder.)
(a) Switch off the inverter – The inverter can be switched of by pressing the
inverter off switch and the control switch simultaneously. And the
load will be automatically transferred to reserve without
interruption.