MC 140 Instruction manual 4-MC140-01en
© 2023 Alarmtech Rev. MC140_2308_en Page 1 of 2
Detectors
Magnetic contact
Recessed mounting
Instruction manual MC 140
DESCRIPTION
The magnetic contact MC 140 is designed for recessed
mounting in frames of doors and windows as a
protection against unauthorised opening. It has 4 screw
terminals.
MOUNTING INSTRUCTIONS
The magnetic contact is designed to be mounted in
predrilled holes in wood or plastic with diameter Ø 19-20
mm
Mounting in ferromagnetic material is not recommended
The contact and magnet should be mounted axial towards
each other. The contact in the stationary part of the
monitored object (ex. door frame) and the magnet in the
movable part (ex. door leaf)
Alignment marks should point in the same direction
After the installation, use an ohmmeter to check the
electrical connections and test the function of the
magnetic contact.
ALIGNMENT MARKS
CIRCUIT DIAGRAM
OPERATING PRINCIPLE
MC 140 magnetic contact has two parts: the contact part with a
reed switch and the magnet part. In its neutral position the
reed switch remains closed under the force of the magnetic
field. Opening the monitored object increases the distance
between the reed switch and the magnet. This reduces the
influence of the magnetic field on the reed switch until it opens
and activates an alarm.
Magnetic contacts should not be installed in the vicinity of
strong magnetic fields.
