EXS
User Manual 10H52260UM60 - Rev. 1 - 10/2017
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6. Disconnect the rectifier input switch Q1 and bypass input switch Q2. At this point, all the internal power supplies
are deactivated and the LCD screen is switched off.
7. If the UPS is equipped with internal batteries, make sure that that they have been isolated from the UPS before
carrying out maintenance work on it. Refer to 6.10 for details.
Warning
1. If maintenance is required, wait 10 minutes for the internal DC bus capacitors to discharge.
2. Hazardous voltages may be present on some parts of the UPS, even when the rectifier input switch, bypass input switch
and battery switch are disconnected. Therefore, UPS maintenance should be carried out by qualified personnel only.
Procedures for Isolating One UPS Module from a Parallel System
Important
These procedures may only be carried out by VERTIV service personnel, or under their supervision.
Warning
Before operation, confirm that the system capacity has sufficient redundancy to avoid system shut down due to overload.
The following procedures apply when it is necessary to isolate one UPS module from the parallel system for repair
due to serious malfunction:
1. Unplugging the REPO terminal deactivates the rectifier, inverter, static switch and battery, while the other UPS
modules in the parallel system continue to supply the load as normal.
2. If the UPS is equipped with an external battery, simply set the corresponding external battery switch to off.
3. Set the rectifier input switch Q1, bypass input switch Q2 and output switch Q5 to off.
At this point, all the internal power supplies are deactivated and the LCD screen is switched off.
4. If the UPS is equipped with internal batteries, make sure that that they have been isolated from the UPS before
carrying out maintenance work on it. Refer to 6.10 .
Warning
1. Post a label on the AC input distribution line (generally at a distance from the UPS) to alert personnel that UPS
maintenance is in progress.
2. Wait 10 minutes for the internal DC bus capacitors to discharge. Then the UPS is completely shut down.
Procedures for Inserting One UPS Module into a Parallel System
Important
These procedures may only be carried out by VERTIV service personnel, or under their supervision.
The following procedures are used to reintegrate a UPS module that has been previously isolated from the parallel
system:
1. If the UPS his equipped with internal batteries, be sure to restore the connection between the UPS and internal
batteries after completing maintenance work on the UPS. Refer to 6.10 for details. Next, close the rectifier input
switch Q1.
At this point, the system is switched on.
2. Close the bypass input switch Q2.
3. Close the output switch Q5, and press the power button for two seconds.
