In article
,
Vet Tech wrote:
Horrors, as I recall that when the builder was doing the loft
conversion, he had to re-route the cable to the sounder and as soon as
he cut it the b***dy alarm went off - even though he had disconnected
the backup battery.

It transpires that most alarms have a big capacitor in the sounder
box. This activates the sounder if the alarm is tampered with eg
having the cables cut or the cover removed. I seem to recall that it
took about an hour before the capacitor drained down. I wasnt too
popular with the neighbours.

They have a re-chargeable battery inside them which is charged by the main
panel power supply.

Question now, as you might expect, is how does one get round this as
the cable has to be cut and extended so that it can re re-routed?

Two of the wires form an anti-tamper (24hr) circuit. Depending on how
sophisticated your system is, shorting those should stop it sounding when
the wire is cut. But you'd need to know which colours were used for this.
Which would mean opening up the main panel. You'd need the installation
instructions for that to know how to prevent it reacting to being tampered
with.

--
*Eat well, stay fit, die anyway

Dave Plowman London SW
To e-mail, change noise into sound.