OPTI-UPS MD120L - Manual (Page 36)

Chapter 3 Operation Instructions 33
33
3.3 Procedure for Switching between Operation Modes
3.3.1 Procedure for Switching the UPS into Battery mode from Normal Mode
Open input switch to cut off the mains, UPS enters the battery mode. If UPS should be switched to
normal mode, wait for a few seconds before closing input switch, so as to supply the mains again. 10s
later, the rectifier will start up automatically to supply power to the inverter.
3.3.2 Procedure for Switching the UPS into Bypass mode from Normal Mode
Select “Tran Byp” on the LCD, or press “off” buttons of each power module in turn.
警告 危 险
Note
In bypass mode, the load is directly fed by the mains power instead of the pure AC power from the
inverter.
3.3.3 Procedure for Switching the UPS into Normal from Bypass Mode
Select exit bypass mode on the LCD.
3.3.4 Procedure for Switching the UPS into a Maintenance Bypass from Normal Mode
In normal operation, this operation instruction will switch the load from inverter input to maintenance
bypass.
警告 危 险
Caution
Before making this operation, read messages on display to be sure that bypass supply is regular and
the inverter is synchronous with it, so as not to have a risk of a short interruption in powering the load.
1. Press “Tran Byp” on the LCD, or press “off” on each power module in turns.
If press ”Tran Byp” on the LCD, the inverter indicator will flash green and the buzzer will alarm.
If press “off” on each power module in turns, the inverter indicator will go off and the buzzer will
alarm.
The load will be transferred to static bypass, and the inverter is closed.
2. Close maintenance bypass switch Q2, the load power will be supplied by maintenance bypass, and
then open the main input breaker Q1, output switch Q3 and battery switch.
警告 危 险
Warning
If you need to maintain the module, wait for 10 minutes to let the DC bus capacitor fully discharge
before removing corresponding module.
3.3.5 Procedure for Switching the UPS into Normal from a Maintenance Bypass Mode
This procedure can transfer the load to normal main mode when the UPS is operating under the
maintenance bypass mode.
1. Close output switch Q3 and main switch Q1.
The bypass indicator goes green and the load power will be supplied by bypass and maintenance
bypass.
2. Open maintenance bypass switch Q2.