The Honeywell MPS51C is an overhead door contact that can be used with any wired alarm control panel. Overhead doors can be hard to protect due to the nature of how an overhead door open and closes. Traditional door contacts do not usually work to protect an overhead door so you must use a special overhead door contact like the MPS51C instead. Overhead door contacts have been specifically designed to work with overhead and roll up doors commonly found in garages and warehouses. The MPS51C consists of a metal encased contact switch and a magnet with an adjustable L bracket.
To install a Honeywell MPS51C, you simply attach the magnet bracket to the bottom corner of your overhead door and drill the contact into the floor of your garage or warehouse. You must make sure that when the overhead door is closed, the magnet is within 2” of the contact as the MPS51C has a standard gap of 2”. With a wide magnet gap of 2”, the MPS51C will not trigger an alarm if the overhead door moves slightly from the wind or someone rattling the door from the outside. Only when the overhead door actually opens up will an alarm be triggered. The 2” magnet gap helps reduce false alarms and allows you to install the overhead door contact more easily.
Once the MPS51C overhead door contact is installed, all you need to do is wire the device to your alarm control panel. The MPS51C has wire leads which you can use to connect to your zone wiring. To protect the wiring, the leads are encased in a 24” armored cable. The armored cable keeps someone or something from accidentally damaging the wire.
The contact switch for the MPS51C is a Form C, SPDT, internal reed switch. As the contact is Form C, SPDT, you can wire the MPS51C to a normally closed or normally open zone circuit depending on what type of contact you alarm control panel requires. You can even wire the MPS51C to a Honeywell 5816 wireless transmitter if you do not want to wire the overhead contact all the way back to your alarm control panel. You would connect the MPS51C normally closed wires to the internal terminal screws on the 5816 and when the overhead contact detects an alarm, the 5816 would send the alarm signal wirelessly back to the wireless receiver of your VISTA Series alarm control panel. The Honeywell MPS51C contact has a rating of 300mA at 30VDC.