4: Operating procedures
44
TS_604_01 PowerWave PW3000/TP User Manual UK 5/1/18
4.13 External Maintenance Bypass operation
An external maintenance bypass circuit, such as that shown in Figure 4.1, allows the UPS system to be totally powered
down while maintaining the load supply through the (unprotected) bypass supply.
Transferring the load from the UPS to the external bypass
1. On the Control Panel of ANY module, press the
ON/OFF
key continuously for more than three seconds.
For ALL modules:
a) The alarm buzzer will sound.
b) The UPS will transfer to ‘on-bypass’ mode and its output will remain live through the (unprotected) bypass supply.
2. Close the external System Bypass Breaker.
3. Open the System Output Breaker.
4. The load is now powered entirely through the (unprotected) external maintenance bypass supply.
To shutdown the UPS modules
5. Open the individual modules’ Output Breakers.
6. On the back of each UPS cabinet in turn, open the input breakers M1 and M2 (position
OFF
).
a) Power will be removed from the UPS output terminals
b) The fans will stop.
c) After a few seconds the UPS LCD display will power down.
7. To totally isolate the UPS modules, open the UPS Input/bypass Isolators and, where used, open the external battery
cabinet fuses/isolator.
Transferring the load from the external bypass to the UPS
On each UPS module in turn
1. Close the external Input/bypass Isolators as required to connect power to the UPS.
2. If an external battery cabinet is used, close the fused isolator on the back of the battery cabinet together with any
circuit breaker connected in the battery line.
3. On the back of the UPS cabinet, close the input breakers M1 and M2 (position
ON
).
a) The fans will start running.
b) The UPS will perform a self-test and will then display the default menu on the LCD.
4. Check that no abnormal conditions are shown on any of the modules’ LCD panel.
System start-up
5. On the UPS Control Panel of ANY module, press the
ON/OFF
key for more than one second.
a) The alarm buzzer will sound and ALL the UPS modules will start.
b) After a few seconds, ALL the UPS modules should switch to the ‘on-line’ mode simultaneously.
6. Check that no abnormal conditions are shown on any of the modules’ LCD panel.
7. On any one of the UPS modules, press the
ON/OFF
key continuously for more than three seconds.
a) All UPS modules will transfer to ‘on-bypass’ mode simultaneously.
8. Check that no abnormal conditions are shown on any of the modules’ LCD panel.
9. Close the external Output Breaker on ALL modules to parallel the UPS output.
10. Close the System Output Breaker, to connect the UPS (‘on-bypass’) output to the load distribution panel.
11. Open the external System Bypass breaker.
12. On any one of the UPS modules, press the
ON/OFF
key continuously for more than three seconds.
13. All UPS modules will transfer to ‘on-line’ mode simultaneously.
CAUTION: This mode is normally used only by fully trained UPS service engineers, for example when repairing/
replacing a UPS system, and is not generally required during normal UPS system operation or use.
