Explaining Sensing Edges

What is a sensing edge? A sensing edge is a touch sensitive switch that sends a signal to start, stop or reverse a motor, or sometimes even to ring a bell. They usually operate on 24 volts, making them useful for hundreds of applications.

Sensing Edge Applications:

• Slide And Swing Gates
• Barrier Arms
• Emergency Switches
• Rolling Doors And Grilles
• Sectional Doors
• Scissor Lifts
• Counter Shutters
• Ovens And Sterilizers (With High-Temperature Edge)


Sensing edges come in two types, Non-Monitored and Monitored. Both monitored and non-monitored sensing edges are available in two styles, Slide-In and Direct Mount. Slide-in style, or extrusion with mounting channel, is the standard form of a sensing edge. It is designed to adapt to existing retainers, or can be used with optional mounting retainers. Each type is also available in 2-wire or 4-wire types.

If you are purchasing a Monitored sensing edge, you will need to choose an edge designator. Refer to the following chart to see where your needs lie. Most customers will want to utilize the T2, 10K Ohm Resistor.

Monitored Sensing Edge Designator
2 Wire Edge Designator Designator Description Operator Manufacturer Outlet Wire Color Code
T1 8.2K Ohm Resistor Typically European Use Green
T2 10K Ohm Resistor Cornell / US Gear Blue
    LiftMaster / Chamberlain  
    VE Power Door  
T3 Diode Capacitor Overhead Door (Only) Red
T4 Capacitor Linear (Transmitter) White
T5 6.8K Ohm Resistor Custom Applications Orange
T6 270K Ohm Resistor LiftMaster CPS Board Violet
4 Wire Edge Designator N/A LiftMaster None


Still have questions about gate sensing edges? Call (888) 378-1043, email sales@gateopenersafety.com, or Shop Sensing Edges now!