40 Chapter 5 Operating Instructions
APM 300 Integrated UPS Single Module And Parallel System User Manual
3. Press and hole the INVERTER ON key for two seconds, and the UPS operates in battery mode.
5.3
Procedures For Transfer Between Operation Modes
5.3.1
Transfer From Normal Mode To Battery Mode
Open the rectifier input switch to cut off the mains input, and the UPS enters battery mode. To return to
normal mode, wait a few seconds and close the rectifier input switch to connect the mains power to the UPS.
The rectifiers will restart automatically after 10 seconds and resume feeding power to the inverters.
5.3.2
Transfer From Normal Mode To Bypass Mode
Press and hold the INVERTER OFF key for two seconds to transfer the UPS to bypass mode.
Note
In bypass mode, the load is being powered by the mains input and is not receiving conditioned power through the
inverters.
5.3.3
Transfer From Bypass Mode To Normal Mode
In bypass mode, press and hold the INVERTER ON key for two seconds. When the inverters are ready, the UPS
transfers to normal mode.
5.3.4
Transfer From Normal Mode To Maintenance Mode
When the UPS is operating in normal mode, use the following procedures to transfer the load from the
inverter output to the maintenance bypass.
Caution
Before performing this operation, read the messages on the LCD to be sure that bypass supply is normal and the
inverters are synchronous with it. If these conditions are not present, there is a risk of a short interruption in powering
the load.
1. Press and hold the INVERTER OFF key on the right side of the operator control and display panel for two
seconds.
The inverter indicator turns off, the status indicator turns yellow and an audible alarm sounds. The load is
transferred to the static bypass and the inverters turn off.
Note
Pressing the SILENCE ON/OFF key cancels the audible alarm, but leaves the warning message displayed until the
appropriate condition is rectified.
2. Close the maintenance bypass switch. The load is now on maintenance bypass.
Warning
If you need to maintain a faulty module, wait about 10 minutes for the internal DC bus capacitors to discharge before
removing the faulty module.
3. Open the rectifier input switch, bypass input switch and output switch.
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