Magnetic door contacts in Pakistan start at Rs 350 for a standard wired contact, Rs 450–550 for recessed types, and Rs 1,199 for heavy-duty metal and rolling-shutter contacts. Relay and timer modules run Rs 949–2,500. ZZ Marts stocks 43 door sensors and control modules for access control and alarm systems, with stores in Karachi and Lahore.
Buying guide
Specifying door contacts and relays
NO or NC decides how the circuit fails
A Normally Closed contact holds the circuit closed while the door is shut, so cutting the wire triggers the alarm exactly as opening the door would. That fail-safe behaviour is why NC is standard for security. Normally Open is used where a signal should only appear on opening — lighting, counters, door-ajar indicators. Getting this wrong is the single most common wiring fault we see.
Surface or recessed is a door-material decision
Surface contacts screw onto the frame and are quick to fit and easy to inspect. Recessed contacts drill into the frame and door edge so nothing is visible — neat on a wooden door, and impossible on a metal one without proper tools.
Metal doors need metal-rated contacts
A standard plastic contact loses most of its gap distance on steel, because the metal distorts the magnetic field. The DH-56 and DH-58 at Rs 1,199 are built for steel doors and rolling shutters, where the gap moves several centimetres as the shutter settles.
Mind the gap tolerance
Every contact has a working gap, usually 15–25mm for standard types and much wider for shutter contacts. Gates and shutters move and sag; a contact fitted at the limit of its gap on installation day will produce false alarms by the second month.
Relay modules are the glue between systems
A 12–24V relay module at Rs 2,200 lets a low-current signal switch a lock, a gate motor or a siren without frying a controller output. The RF versions add a remote so a door can be released from a desk. Adjustable timer relays hold the lock open for a set number of seconds and then drop it again.
Frequently asked questions
What is the difference between NO and NC door sensors?
Normally Closed keeps the circuit complete when the door is shut, so both opening the door and cutting the wire trigger the alarm. Normally Open completes the circuit only when the door opens. Security systems use NC; signalling and lighting usually use NO.
Which door sensor should I use on a metal shutter?
A heavy-duty metal rolling-door contact such as the DH-58. Standard plastic contacts lose gap distance on steel and false-trigger as the shutter settles.
How much does a magnetic door contact cost in Pakistan?
Standard wired contacts start at Rs 350, recessed reed contacts Rs 450–550, and heavy-duty metal or rolling-door contacts Rs 1,199.
What is a relay module used for in access control?
It isolates the controller from the load. The controller sends a small signal; the relay switches the full current the lock, siren or motor needs. It also allows a timer or a remote to be added to a door.
Can I use a door contact to switch a light instead of an alarm?
Yes, using a Normally Open contact and a relay rated for the lamp load. Do not wire mains lighting directly through the contact.
Do recessed contacts work on aluminium doors?
Only with a metal-rated model. Aluminium affects the field less than steel does, but a standard contact will still lose gap distance.