GRI 4400-A Industrial Surface Mount Switch Set, Wide Gap, Closed Loop

The GRI 4400-A is a heavy-duty, surface-mounted magnetic contact switch designed for industrial intrusion alarm systems and door position monitoring. Featuring a 2-1/2-inch (63.5 mm) standard operating gap, Form A normally open reed switch, and 36-inch armored cable, it monitors chain-link gates, overhead garage doors, safes, and walk-in freezer doors. The weather-resistant aluminum housing supports temperatures from -40 F to 257 F. Rated for 10W maximum switching power, 200 VDC, and 0.5A, the switch includes mounting hardware and carries a limited lifetime manufacturer warranty.

GRI 4400-A Industrial Wide-Gap Magnetic Contact Switch with 36-Inch Armored Cable

The George Risk Industries (GRI) 4400-A Industrial Surface Mount Magnetic Contact provides heavy-duty door and gate position monitoring for commercial intrusion alarm systems and industrial security applications. Part of the GRI 4400 Series, the switch features a closed-loop, Form A normally open reed contact and a standard operating gap of 2-1/2 inches (63.5 mm). Its wide-gap configuration accommodates movement and alignment variations commonly encountered on chain-link gates, overhead garage doors, and industrial access points. When the supplied magnet is positioned within the specified operating gap, the reed switch closes the alarm monitoring circuit. Separating the magnet from the switch opens the circuit, allowing a compatible intrusion alarm control panel to identify an open or unsecured entry point. The rugged aluminum construction and armored cable support installation in environments where conventional residential magnetic contacts are unsuitable.

The GRI 4400-A features a weather-resistant aluminum enclosure and an integrated 36-inch (91.4 cm) armored cable that protects the switch wiring against mechanical damage. The magnetic switch and matching magnet each measure approximately 2.6 inches long, 0.875 inches wide, and 0.60 inches deep (66 x 22.2 x 15.2 mm). The Form A reed contact provides a maximum switching power rating of 10W, maximum switching voltage of 200 VDC, and maximum switching current of 0.5A, with maximum initial contact resistance of 0.150 ohms. These ratings represent independent electrical limits, and the connected circuit must remain within the 10W power limit. GRI specifies an operating temperature range of -40 F to 257 F (-40 C to 125 C), supporting applications exposed to extreme temperatures. The 4400 Series is documented as UL and ULC Listed, and GRI provides a limited lifetime warranty covering defects in materials, workmanship, and manufacturing.

The 4400-A magnetic contact switch set is designed for surface mounting on metal gates, overhead doors, freezer entrances, and other industrial access points requiring reliable magnetic alignment. The switch and magnet feature mounting holes spaced approximately 2.0 inches (50.8 mm) apart, allowing secure attachment using the included mounting hardware. The armored cable extends from the switch housing and can be routed to a compatible alarm initiating circuit or door monitoring input. GRI provides an S-12 mounting bracket with the switch set and offers additional mounting accessories for specialized installations. The optional GRI 5226 case spacer accommodates applications requiring additional clearance, while compatible gate mounting brackets support chain-link fencing and other nonstandard surfaces. Longer armored cable lengths, vinyl-jacketed cable configurations, built-in end-of-line resistors, diodes, and supervisory loops are available through separately specified configurations or factory requests.

The GRI 4400-A wide-gap industrial magnetic contact supports intrusion detection and position monitoring in warehouses, manufacturing facilities, commercial storage buildings, gated properties, and refrigerated environments. Its 2-1/2-inch operating gap, armored cable, and weather-resistant aluminum housing make it suitable for installations exposed to vibration, temperature changes, and mechanical movement. The related GRI 4400 provides the same closed-loop Form A switching arrangement with a 36-inch two-conductor vinyl-jacketed cable instead of armored cable. Applications requiring additional contact configurations can use the GRI 4402-A SPDT switch set or the GRI 4405-A DPDT switch set, which provide alternative monitoring circuit arrangements. The 4400-A is a passive magnetic contact and does not independently provide audible alarms, wireless communication, or door locking functions. Installers must verify mounting alignment, circuit resistance, electrical load limits, and alarm panel compatibility before placing the switch into service.