Technical Data Bulletin

Heavy Duty Safety Switches Class 3100
Sample Applications
Locking Position—
Designations
L-O-R
L-C-R
L-O-C-R
L-O-H
L-C-H
L-O-C-H
Devices locked open
with key removed
Devices locked closed
with key removed
Devices locked open
or closed with key
removed
Devices locked open
with key held
Devices locked closed
with key held
Devices locked open or
closed with key held
Multi-lock interlock
(More than one key
per lock)
Diagram Symbols
NOTE: Device
locked open =
switch in OFF (O)
position. Deviced
locked closed =
switch in ON (I)
position.
A-1 A-2 A-3
Device normally
open
Device normally
closed
Direction of key
transfer
Key
interchange
number
Key
1. To prevent two devices from being closed simultaneously:
Figure 1 - Sample Application
A-1
A 1
L-O-R L-O-R
A B
A-1
Figure 1 shows two devices that are not to be closed at the same time. Using key
interlocks shown, only one key is required to operate the system
• Both devices are shown open, therefore, the key is free
• To close any one device insert the key and turn that particular lock
• The key is held in this lock until the device is locked open
• The procedure described above is the same for two devices, neither of which
is to be opened simultaneously
2. To prevent the opening of switch A when circuit breaker B is closed:
Figure 2 - Sample Application
A-1
L-C-R L-O-R
A
B
A 1
Figure 2 shows switch A and circuit breaker B in the closed position.
• Key A-1 is held in circuit breaker B interlock
• Open the circuit breaker
• Turn key A-1 in the L-O-R interlock on circuit breaker B to lock open; Key A-1
is now free
• Insert key A-1 in the L-C-R interlock on switch A and turn to unlock
• Open switch A. Key A-1 is now held; Reverse the sequence to restore
service
3. To prevent operation of switch A when circuit breaker B is closed. Permits
re-closing of the circuit breaker for servicing when switch is locked open:
Figure 3 - Sample Application
A-1
L-O-C-R L-O-R
A
B
A 1
Switch A and circuit breaker B are in the closed position.
• Key A-1 is held in the circuit beaker interlock
3100CT1602 37