GRI-28C Indoor Magnetic Contact Sensor with concealed terminals on the bottom

Remotely monitor magnetic contact-closure sensors using ControlByWeb modules. The GRI Closure Sensors can be installed on most doors, windows, cabinets, security/control boxes, and more.

How do contact-closure sensors work?
Contact-closure sensors are comprised of two parts: a magnetic reed switch, and a magnet. The magnetic reed switch is mounted on the door or window frame, while the magnet is mounted to the door or window itself. When the magnet comes in range of the magnetic reed switch, the switch turns on or off based on the wiring configuration.

Magnetic contact sensors with ControlByWeb® products
Connected to a ControlByWeb product's digital input, once the magnetic switch is in proximity of the magnet, it will open or close its contacts (depending on configuration), turning the digital input on/off. The ControlByWeb product can send an email/text and/or trigger a relay in a local or remote location.

Contact-Closure Sensor Wiring Diagrams
Both the 29C and 28C have 3 terminals which allow to choose between a normally-open (NO) or normally-closed (NC) configuration.

Features: 

• Options for N/O or N/C circuits
• Reliable magnetic reed switches
• Easy to install

Compatible Products:
Contact-closure sensors are compatible with all ControlByWeb® products that have a digital input.

• WebRelay™
• WebRelay Wireless™
• X-301™
• X-310™
• X-408™
• X-410™
• X-420™
• X-332™
• Five-Input Module™
• X-320™
• X-320M™
• WebSwitch Plus™
• WebRelay-10 Plus™
• X-15s™
• X-17s™
• X-19s™
• X-20s™
• XW-111™
• XW-112™

Contact-Closure Sensor:

GRI-28C

• Terminal Locations: Bottom
• Circuit Types: N/O and N/C
• Gap Distance: 1" (5/8" on steel)
• Mounting Options: Wall screw mounting
• Dimensions (Length × Width × Height): 2 1/2" × 1/5" × 5/8"