Door Contacts

A reed switch in the contact is held in one state by a magnet fixed to the door, and opening the door moves the magnet away and changes the circuit, which the panel reads as an opening. The CQR FC505, for example, is a normally closed circuit that goes open when the magnet is removed. The contact goes on the frame and the magnet on the door or window.

Grade 3 is the higher security grade: the Aritech DC148R4.7, for example, is a high security contact that meets requirements for opening distance, magnet polarisation and magnet strength. The CQR SC570/WH/MD/MULTI/G3 is a Grade 3 contact designed for commercial and high-risk intruder alarm installations. Grade 3 examples include the Aritech DC148R4.7 and Elmdene VS303, and Grade 2 examples the CQR SC525/WH/4C and Pyronix MCNANO-WE.

A heavy-duty roller shutter contact on an armoured lead. The Elmdene EN3-RSA-GN is a Grade 3 anodised aluminium contact with an 18mm operating gap, and the CQR RS002/ALI/1M/G2/A a Grade 2 contact with 1 m armoured cable. The Knight F10CMULTI has a roughly 50 mm operating gap for large doors. On a wireless system, the Pyronix MCEXTERNAL-WE is an IP66 contact for shutters, gates and garages.

A flush contact where the frame can be drilled, because it is hidden and harder to tamper with; a surface contact where the frame is too thin or cannot be drilled. The Elmdene EN3-QFC-GN is a 20mm Grade 3 flush contact, the CQR FS610/WH is flush with a surface adaptor included, and the CQR SC525/WH/4C is a surface contact made for patio doors.

One made for the same radio system, because a wireless contact pairs with its own maker's panel. Ajax DoorProtect models need an Ajax hub, Hikvision contacts such as the DS-PDMCS-EG2-WE(B) an AX PRO panel, the Pyronix MC1Z1-WE an Enforcer (or EURO with a ZEM), and the Texecom GHA-0001 a Premier Elite panel or a Ricochet expansion pack.

Yes. The Hikvision DS-PDMCX-E-WE and Pyronix MCEXTERNAL-WE are IP66 wireless contacts for outdoor use, and the Pyronix is made for gates, garages, sheds and roller shutters with a 70 mm magnet. For wired systems, the Aritech DC115 is a sealed aluminium contact with 2 m armoured cable for metal doors, overhead doors, fences and gates.

Where the panel uses resistor-monitored zones, yes, and the contact must carry the values that panel expects. Pre-resistored contacts save fitting them by hand: the Aritech DC148R4.7 has a built-in 4k7 EOL resistor and the Elmdene EN3-QFC-GN integral 1k/1k resistors. The DMP HSS-L2D-000 has no built-in resistor, and Dantech DA314 resistors can be fitted separately.

Yes, some contacts add a shock sensor that reacts to impacts on the frame. The Hikvision DS-PDMCK-EG2-WE(B) combines a wireless magnetic contact with shock and tilt detection and has two wired inputs for extra detectors. The Ajax DoorProtect Plus Fibra is the wired equivalent for Ajax Fibra hubs, with adjustable shock sensitivity and a tilt threshold.

Several years, by the makers' figures. The Ajax DoorProtect U Jeweller 121293.03.WH1 has a typical battery life of up to 7 years on its pre-installed CR123A, the Texecom GHA-0001 a typical 4 years, the Hikvision DS-PDMCK-EG2-WE(B) up to 3 years, and the Pyronix MCNANO-WE 2 years. Real life depends on how often the door opens and on the radio settings.