American Power Conversion 240-320kW 480V , 2.7 Isolating one UPS in a Parallel Configuration for Service/Maintenance

16 User Guide APC Silcon 240-320kW 480V UPS
990-4039
Stop/Start UPS and Operating the External Service Bypass
2.7 Isolating one UPS in a Parallel Configuration for Service/Maintenance
2.7.1 Isolating one UPS in a Parallel/Redundant System
In a redundant system one UPS may be isolated for service/maintenance without affecting
other parallel UPS(S).
2.7.2 Switching Back the UPS to Normal Parallel/Redundant Operation
The UPS will automatically switch to normal operation and start load-sharing with the other
parallel UPS(s).
Service
bypass
switch
Load
Utility
APC Silcon
UPS
APC Silcon
UPS
Q010a
Q001a Q002a
Q004
Q010b
Q001b
Q002b
Q003
H003
H004
H002b
H002a
H010a
H010b
Service
bypass
Load
APC Silcon
UPS
APC Silcon
UPS
switch
Utility 1
Utility 2
Dual UtilitySingle Utility
Action
1. Check that the remaining UPS(s) will be able to carry the load when one UPS is isolated.
2. Switch off the system to be isolated for maintenence by pushing the red OFF button.
3. Disconnect output and utility by setting output switches (Q002) to position 0 and input
switch (Q001) to position 0. Disconnect battery by opening battery breaker.
4. If system has dual utility, set the bypass input switch (Q010) to position 0.
Action
1. Set the input switch (Q001) and the output switch (Q002) to position 1.
2. If system has dual utility, set the bypass input switch (Q010) to position 1.
3. Charge capacitors, connect battery and start up the UPS as described in 2.4.1. Start UPS
(from complete power down).