A-B 440N-G02112 Safety Switch

A-B 440N-G02112 Safety Switch

 

 

The Allen-Bradley 440N-G02112 is a Guardmaster Ferrogard non-contact magnetic safety switch, used for machine guard door position detection and safety interlocking.

Product Information

• Brand: Allen-Bradley (Rockwell Automation)
• Series: Guardmaster Ferrogard 440N
• Part Number: 440N-G02112
• Type: Non-contact magnetic safety switch
• Function: Safety door monitoring (guard interlock)
• Contact configuration: 1 NC safety contact + 1 NO auxiliary contact
• Connection: 3 m pre-wired cable
• Housing: Stainless steel industrial enclosure

Working Principle

This device uses a magnet + sensor pair:

• When door is closed → magnet is aligned → NC safety contact stays closed
• When door opens → magnet moves away → safety contact opens → machine stops

It is a non-contact safety interlock, so there is no physical switch wear like mechanical limit switches.

System Role

It is used in machine safety circuits, typically connected to:

• Safety relays
• Safety PLC inputs
• Machine stop circuits

It does not control outputs or power loads—it only provides safe door status feedback.

Typical Applications

• Machine guarding doors
• CNC machine enclosures
• Robotic safety fences
• Conveyor safety gates
• Industrial automation safety systems
• Heavy machinery protection systems

Key Features

• Non-contact magnetic sensing (no mechanical wear)
• Stainless steel housing for harsh environments
• Dual contact output (1 safety + 1 auxiliary)
• High reliability for safety-rated systems
• Resistant to vibration and contamination

Precautions

• Must be installed with correct magnet alignment direction
• Incorrect alignment or distance can cause safety faults or LED errors
• Must be used in a properly designed safety-rated circuit (SIL/PL system)
• Requires correct spacing and mounting orientation
• Cable routing should avoid electrical noise interference