Instruction Manual
124
HS1C-P Interlock Plug Unit with Door Lock
Circuit Diagrams and Operating Characteristics
With Solenoid
Interlock 
Switch Status
Status 1 Status 2 Status 3 Status 4 Status 5
• Door closed
• Interlock plug is 
installed
• Solenoid de-
energized
• Door closed
• Interlock plug is 
installed
• Solenoid energized
• Door closed
• Interlock plug is 
removed
• Solenoid energized
• Door closed
• Interlock plug is 
removed
• Solenoid de-
energized
• Door open
• Interlock plug is 
removed
• Solenoid de-
energized
Door
Circuit Diagram
Interlock Plug
Monitor
Circuit
Main
Circuit
Solenoid
Power
7
8
1
2
3
4
5
6
Microswitch turns on when
the solenoid is energized.
Interlock Plug
Monitor
Circuit
Main
Circuit
Solenoid
Power
7
8
1
2
3
4
5
6
Microswitch turns on when
the solenoid is energized.
Interlock Plug
Monitor
Circuit
Main
Circuit
Solenoid
Power
7
8
1
2
3
4
5
6
Microswitch maintaines ON
status when the plug is
removed.
Interlock Plug
Monitor
Circuit
Main
Circuit
Solenoid
Power
7
8
1
2
3
4
5
6
Microswitch maintaines ON
status when the plug is
removed.
Interlock Plug
Monitor
Circuit
Main
Circuit
Solenoid
Power
7
8
1
2
3
4
5
6
Main Circuit 3-4: Closed 3-4: Closed 3-4: Open 3-4: Open 3-4: Open
Monitor Circuit 1-2: Open 1-2: Closed 1-2: Closed 1-2: Closed 1-2: Closed
Solenoid 
Power
5-6: Power OFF 5-6: Power ON 5-6: Power ON 5-6: Power OFF 5-6: Power OFF
Remarks
• Door locked
• Interlock plug is 
retained (cannot turn)
• Machine can operate
• Door locked
• Interlock plug can be 
removed by turning
• Machine can operate
• Door can be opened
• Interlock plug is 
removed
• Machine cannot 
oper ate
• Door can be opened
• Interlock plug is 
removed
• Machine cannot 
oper ate
• Machine cannot 
oper ate
Without Solenoid
Interlock Switch 
Status
Status 1 Status 2 Status 3
• Door closed
• Interlock plug is 
installed
• Door closed
• Interlock plug is 
removed
• Door open
• Interlock plug is 
removed
Door
Circuit Diagram
Interlock Plug
Monitor
Circuit
Main
Circuit
1
2
3
4
5
6
7
8
Interlock Plug
Monitor
Circuit
Main
Circuit
7
8
1
2
3
4
5
6
Interlock Plug
Monitor
Circuit
Main
Circuit
7
8
1
2
3
4
5
6
Main Circuit 3-4: Closed 3-4: Open 3-4: Open
Monitor Circuit 1-2: Open 1-2: Open 1-2: Closed
Remarks
• Door locked
• Interlock plug can be 
turned to remove
• Machine can operate
• Door can be opened
• Interlock plug is 
removed
• Machine cannot 
oper ate
• Interlock plug is 
removed
• Machine cannot 
oper ate






