GRI 4402 Industrial Surface Mount Switch Set, Standard Gap, SPDT

The GRI 4402 Industrial Surface Mount Magnetic Contact is a heavy-duty, wide-gap security switch designed to monitor the open and closed positions of overhead garage doors, chain-link gates, safes, and walk-in freezer doors. Featuring a 2-1/2-inch standard operating gap, single-pole double-throw (SPDT) Form C contacts, and a weather-resistant aluminum housing, the 4402 provides normally open and normally closed circuit options for wired intrusion alarm systems. Its electrical ratings include 175 VDC maximum switching voltage, 0.25A maximum switching current, and 5W maximum contact power. The switch is UL and ULC listed and carries GRI's lifetime warranty against manufacturing defects.

GRI 4402 Industrial Wide-Gap SPDT Surface Mount Magnetic Contact

The George Risk Industries (GRI) 4402 Industrial Surface Mount Magnetic Contact is a heavy-duty security switch engineered to monitor industrial doors, commercial gates, and other movable entry points connected to wired intrusion detection systems. Part of the GRI 4400 Series, the 4402 combines a rugged, weather-resistant aluminum enclosure with a 2-1/2-inch standard magnetic operating gap, making it suitable for installations where conventional close-gap magnetic contacts cannot accommodate the spacing between a moving door or gate and its mounting surface. The contact is designed for chain-link security gates, overhead garage doors, warehouse entrances, safes, and walk-in freezer doors. Its surface-mounted construction allows the switch and matching magnet to be installed on exposed door and frame surfaces, while the included mounting hardware and S-12 bracket support installation on industrial security openings.

The GRI 4402 utilizes a single-pole double-throw (SPDT) Form C reed switch that provides both normally open and normally closed circuit connections through a common terminal. This configuration enables the contact to support open-loop and closed-loop alarm monitoring according to the requirements of the connected security control panel. Manufacturer electrical specifications include a maximum initial contact resistance of 0.140 ohms, maximum contact rating of 5 watts, maximum switching voltage of 175 VDC, and maximum switching current of 0.250 amperes. The switch is rated to operate across a temperature range of -40 F to 257 F (-40 C to 125 C), accommodating demanding industrial environments and temperature-sensitive applications such as refrigerated storage facilities. Both the magnetic switch and actuator magnet use durable aluminum housings, with the switch enclosure measuring approximately 2.6 inches long, 0.875 inches high, and 0.60 inches wide.

For commercial intrusion detection, the GRI 4402 monitors the position of movable gates and doors through magnetic reed-switch activation. The supplied magnet changes the state of the SPDT contact as the monitored opening moves between its closed and open positions, allowing a compatible alarm system to recognize an opening event or changes in circuit continuity. The wide-gap magnetic design accommodates the larger mounting clearances commonly encountered on chain-link gates, overhead doors, industrial enclosures, and warehouse access points. Its weather-resistant aluminum construction supports use in environments exposed to changing temperatures and incidental moisture, while its surface-mounted configuration provides access for inspection, wiring, and maintenance. The switch is a passive magnetic contact and does not require a separate operating power supply, although its circuit must remain within the manufacturer's electrical switching ratings.

The GRI 4402 includes a standard 36-inch lead and surface-mount installation hardware, with optional cable lengths, protective cable configurations, and mounting accessories available through George Risk Industries. The standard 4402 configuration is differentiated from the 4402-A armored-cable version, which provides additional mechanical protection for exposed wiring. Installers can also specify optional end-of-line resistors, diodes, and supervisory loops for compatible alarm monitoring applications. The GRI 5226 case spacer supports installations requiring additional mounting clearance, while dedicated industrial gate and garage door mounting kits provide alternative installation arrangements. The 4402 is UL and ULC listed and manufactured in the United States. Backed by a lifetime warranty against defects in workmanship, materials, and factory manufacturing, the GRI 4402 offers a durable SPDT magnetic contact solution for commercial, industrial, and perimeter intrusion security systems. Installers should verify magnetic alignment, operating gap, circuit configuration, and environmental exposure requirements before installation.