Alarm Systems - PIR and Magnetic Contacts
For most PIRs within
alarm systems you need 6 wires:- 2 for power (+ and 12 volts) 2 for
the alarm loop and 2 for the 24 hour tamper loop. Some PIRs need an
extra pair of wires so you can tell which is the FIRST TO TRIGGER, but
not all panels can use this signal. Most PIRs have jumper links or
switches inside to turn off the LED and to enable Pulse count (for
electrically noisy or problem areas etc.). Most users would want the LED
NOT to illuminate in a bedroom (you can still test them by using the
walk test facility present in most panels, that gives a chime when
activated).
For most magnetic door/window contacts you need 4 wires:- 2 for the
alarm loop and 2 for the 24-hour tamper loop. Just trim back the power
wires (usually designated black and red), or if a connector block is
used, screw them into 2 unused screw connections, in case you ever need
to modify that zone. However, bear in mind that if your door magnet is
first in-line on that zone, and you have PIRs further down the line,
you will need to ensure that the red/black 12v power pair is continued
through to the PIR and any other device that needs 12 volt power.
