Page 4 - MAGNETIC CONTACTS and accessories

MAGNETIC CONTACTS
MAGNETIC CONTACTS MC 100 SERIES
BASIC THEORY OF OPERATIONS AND PERFORMANCE CHARACTERISTICS

OPERATING PRINCIPLE MOUNTING ON STEEL
A magnetic contact has two parts, the contact with one or more reed switches The Alarmtech contacts are designed for mounting on steel doors, safes, filing
and the magnet. In its neutral position the reed switch remains closed under cabinets, gate and roll-up garage doors. There are many specially designed
the force of the magnetic field. Opening the object being monitored increases accessories for this kind of applications. Mounting on steel doesn’t drain
the distance between the reed switch and the magnet. This reduces the the magnet, however it reduces its magnetic field, resulting into smaller
influence of the magnetic field on the reed switch until it opens and activates make/break gaps of the magnetic contact.
an alarm. Please note that the opening gap varies with the environment and HIGH SECURITY CONTACTS
type of installation, the values in this catalog are nominal and should be seen High security contacts have one or more extra reeds inside to protect the
as a reference only. For each installation the gap has to be tested to ensure full contact from sabotage. Two distances need to be determined. The first is the
functionality of the contact. closing distance when the contact approaches the magnet and the second
THE REED SWITCH when the sabotage reed opens when the magnet is very close to the contact.
In all Alarmtech contacts only the highest quality and performance switches To get the highest security always place the magnet as close as possible to
are used. This ensures a safe contact function and guarantees an extremely this second distance.
long operating life and fits the most demanding applications. BUILT-IN EOL (END OF LINE) RESISTORS
THE MAGNET Every contact can be delivered on customer request with built-in resistors
of any resistor value in E36 series 1%. The resistor can be mounted parallel
Alarmtech use two different materials in the magnets for creating a big gap and/or in series with the reed switch. Minimum order required is 100 pcs. Add
between the magnet and the contact part. When the contact and the magnet P to the resistor value for parallel connection and S to the resistor value for
is mounted parallel with each other a long magnet is normally needed and if serial connection to the reed switch.
mounted opposite each other a short magnet is used containing a different
material. SOME TYPICAL RESISTOR COMBINATIONS
FOR END OF LINE CONFIGURATIONS
FUNCTION OF A STANDARD CONTACT P S Order code Control Panel
Two gaps are important: The closing gap, when the magnet is approaching the 1k 1k MC XXX-P1kS1k Honeywell Galaxy, Galaxy Flex, Jablotron, Satel, Paradox
contact and the opening gap, when the distances increase between the parts. 3k3 3k3 MC XXX-P3,3kS3,3k Caddx
The opening gap is approximately 10% wider than the closing gap depending 4k7 2k2 MC XXX-P4,7kS2,2k ADE, Bosch, Pyronix, Scantronic, Texecom
on the necessity for a stronger magnetic field to close the contact. 4k7 4k7 MC XXX-P4,7kS4,7k Aritech, Siemens-SPC
5k6 5k6 MC XXX-P5,6kS5,6k
DSC
2