Technical Data Bulletin

2-26
© 2019 Schneider Electric
All Rights Reserved
Enclosures
Key Interlock Systems—Factory Installed
Only
schneider-electric.us
Class 736, 1130
Sample Application—3 (See Figure 3)
To prevent operation of switch A when circuit breaker B is closed. Permits reclosing of
circuit breaker for servicing when switch is locked open.
Figure 3
A-1
L-O-C-R L-O-R
A
B
A 1
Switch A and circuit breaker B are in closed position. Key A-1 is held in circuit breaker
interlock.
•
Open circuit breaker.
•
Turn key A-1 in L-O-R interlock on circuit breaker B to lock open. Key A-1 is now free.
•
Insert key A-1 in L-O-C-R interlock on switch A and turn to unlock.
•
Open switch A.
•
Turn key A-1 in L-O-C-R interlock on switch A to lock open. Key A-1 is now free.
•
Return key A-1 to circuit breaker interlock and unlock for operation during servicing
period.
Reverse sequence to restore service.
Sample Application—4 (Main-Tie-Main) (See Figure 4)
To prevent paralleling of lines A and B.—Two loads, fed from either source.
Figure 4
L-O-R
C
L-O-R
A
A
NM
A 1
L-O-R
A 1
A-1
B
B
Circuit breaker A is closed to supply load M. Circuit breaker B is closed to supply load N.
Tie-circuit breaker C is open. Keys A-1 are held in interlocks on both circuit breakers A
and B. Tie-circuit breaker C cannot be closed unless either A or B is locked open.
To transfer load N to circuit breaker A, proceed as follows:
•
Open circuit breaker B.
•
Turn key A-1 in L-O-R interlock on circuit breaker B to lock open. Key A-1 is now free.
•
Insert Key A-1 in L-O-R interlock on tie-circuit breaker C and turn to unlock. Key A-1 is
now held.
•
Close tie-circuit breaker C.
Reverse sequence to restore service.
Load M can be supplied through circuit breaker B in a similar manner.
2
METERING EQUIPMENT
5/15/2019