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8. System Operation: Configuration 2 Interlocks
The following user instructions are for a three-circuit breaker MBP configured to be controlled by a 2-interlock, 1-key breaker interlock
system.
Do not operate the SW2 circuit breaker unless the UPS is in BYPASS mode! Failure to follow the operating instructions for this
equipment could result in equipment damage, fire, severe injury or death!
Normal Operation
The UPS AC input breaker SW1 is Closed/On. The maintenance bypass breaker SW2 is locked Open/Off with the interlock locking bolt in
the extended position and Key A1 held captive. The maintenance isolation breaker SW3 is Closed/On, with the interlock locking bolt in the
withdrawn position.
Transfer to Maintenance Bypass
1. Transfer the UPS to the Bypass mode.
2. Retract the bolt at SW2 by rotating the key.
3. Turn ON SW2 breaker and remove the key.
4. Insert the key in SW3 and retract the bolt.
5. Turn OFF SW3 breaker.
6. Turn OFF SW1.
7. The UPS is now ready for routine maintenance.
8. If further maintenance requires a total shutdown of the UPS and isolation from the input, the SW1 breaker must be opened/turned off
and the battery supply to the UPS must be disconnected. Refer to your UPS manual for proper shutdown procedures.
Return to Normal Operation
1. If the SW1 breaker was opened/turned off for maintenance, follow the UPS manual for proper startup procedures. To restore input power
to the UPS, close/turn on the SW1 breaker. Make sure the UPS is in BYPASS mode before proceeding!
2. Turn ON the SW3 breaker.
3. Rotate the key to extend the bolt at SW3; remove the key.
4. Turn OFF SW2 breaker.
5. Insert the key in SW2 and extend the bolt.
6. Transfer the UPS from bypass mode to line mode (online mode).
POSITION 1 (NORMAL OPERATION)
POSITION 1 (IN EXTERNAL BYPASS)
SW1
SW2
SW3
SW1
SW2
SW3
UTILITY INPUT
UTILITY INPUT
TO UPS AC OUTPUT
TO UPS AC INPUT
TO UPS AC INPUT
OUTPUT TO LOAD
OUTPUT TO LOAD
TO UPS AC OUTPUT
