48 1600XPi Series UPS Installation and Operation Manual – 60616-014
19 Optional MB (Maintenance Bypass) Units
19.1 Internal Maintenance Bypass
The following illustration shows the circuit power ow when the UPS is operating in the optional Maintenance Bypass
mode. The input jumper on the UPS must be set for 240 VAC.
NOTICE
Ensure the UPS is in Static Bypass before switching the unit from UPS to Maintenance
Bypass mode or from Maintenance Bypass to UPS mode. Failure to do so could result
in damage to the maintenance bypass switch or the UPS.
The Internal Maintenance Bypass unit can only be used for 240 V applications. Ensure
the UPS voltage selector jumper is set to 240 V. See Section 7.1 on page 12 for the
correct 240 V setting.
POWER FLOW IN MAINTENANCE BYPASS MODE FOR ALL MODELS
Output
Power
Line Filter Inverter
*Static Switch
Isolation
Transformer
Input
Power
Input
Fuse
Power Flow
Bypass
* Switches are
solid state
devices.
MCCB
Output
Fuse
Batteries
+
–
Rectier/
Chopper
Maintenance
Bypass Switch
Negative
Bus
TVSS
The optional internal maintenance bypass is mounted on the rear of the UPS.
Internal Maintenance Bypass Instructions:
From Inverter Mode to Maintenance Bypass Mode
1. Turn the RUN/STOP switch to the STOP position on the UPS.
2. Turn the Maintenance Bypass Switch to the Bypass position. The Bypass LED should be ON and the UPS LED
should be OFF. The LEDs are next to the Maintenance Bypass switch, on the back of the UPS.
3. Turn the MCCB input breaker on the UPS to the OFF position. The UPS is now operating in Maintenance Bypass
Mode.
From Maintenance Bypass Mode to Inverter Mode
1. Turn the MCCB input breaker on the UPS to the ON position.
2. Turn the Maintenance Bypass switch to the UPS position. The UPS LED should be ON and the Bypass LED OFF.
3. Turn the RUN/STOP switch to the RUN position on the UPS. The UPS is now operating in the UPS Mode.