MITSUBISHI ELECTRIC 2033D SERIES UPS systems - Manual (Page 45)

MITSUBISHI ELECTRIC 2033D SERIES UPS
MITSUBISHI
ELECTRIC 2033D SERIES UPS
OWNERS / TECHNICAL MANUAL
Page Number:
3-13
3.5 Maintenance bypass set-up procedures
CAUTION: 1. The following instructions are for single operation ONLY.
2. To avoid parallel operation between a bypass source of one module and an
inverter source of another module, which may result large cross current
between the two modules,
DO NOT OPERATE THE MAINTENANCE
BYPASS SWITCH UNDER PARALLEL OPERATION (Must be kept
in NORMAL position).
A) Transfer of load from inverter to maintenance bypass
1. Stop the inverter by pressing the START/STOP key on the LCD’s Main Menu (see
Figure 2.3). Simultaneously press the two (2) STOP keys per the instructions. (Note :
inverter STOP function inhibited if bypass and inverter are out of sync.)
2. Confirm via the flow diagram on the LCD that the load is fed from the UPS’ static
bypass line. Also confirm that the “BYP.OP.” LED is on (No.3 LED on Figure 2.1)
3. After confirming Step2, rotate MBS (52CS) clockwise to the “TRANSFER” position
(see figure 1.4 for the location of 52CS). The MBP Lamp (No.7 Lamp on Figure 2.1)
will be illuminated. (Do not rotate MBS (52CS) if the load is NOT fed by bypass
source).
4. After 3 seconds, rotate 52CS clockwise to the “BYPASS” position.
5. UPS can now be powered down.
6. Transfer complete. Load is fed from the external source (Utility or generator).
B) Transfer of load from maintenance bypass to inverter
1. Confirm that the Static Bypass line is on and energized.
2. Rotate 52CS counterclockwise from the “BYPASS” position to the “TRANSFER”
position, wait 5 seconds.
3. On the UPS, confirm the “BYP.OP.” LED is on. If not, press the “STOP” button.
4. Rotate 52CS counterclockwise to the “NORMAL” position.
5. Close the external input breaker. Confirm that the converter operates and DC
contactor 72B closes.
6. Press “START” button on the LCD panel to transfer the load to inverter source. The
“INV.OP.” LED will be illuminated.
7. Transfer complete. Load now powered by the inverter.