Re: Failure rate of window / door magnetic sensors

["Roland More" <NoSpamroland@xxxxxxxxxxxx>]

Funny we were just having a discussion about that here. According to one
gentleman posting here, all of your contacts should be bad, but I see you
report different contacts failing with different modes of failure. That what
I typically see after a lightning strike. The simple explanation is that the
contacts stuck closed were heated during the lightning strike event enough
to "weld" the metal in the reed switch in the contact together. The
dangerous cheapskate solution is to take the battery from the alarm panel,
hook it to the contact for a second or two, and rap the contact with the end
of a screwdriver. That is reheating the contact and unfreezing the "weld".
This is the repair technique of the dreaded trunk slammer and should never
be done in my opinion. The others that were burnt "open" when the reed
switch was damaged to the point where there was no current flow possible
anymore. If you have a meter I would check each switch by itself, even the
ones that seem to work properly. If you find a switch showing anything
greater than one (1) Ohm I would consider it suspect and replace it along
with the rest of the bad contacts.


<borne@xxxxxxxx> wrote in message
news:1191245853.355980.22100@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>I installed my own security system 8 years ago.  Last week, lightning
> struck our house and fried all sorts of things.  I discovered about
> half of my window and door magnetic switches were bad.  The control
> panel was fried, but I fixed that.
>
> I have Ademco mini stick on NC sensors.  Of the broken ones, all but
> one was broken so that they are always closed.  One broke always
> open.
>
> I can assume the one that was open was caused by the lightning
> strike.  But what about the others that are broken closed?  Did the
> lighting do that, or do these types of switches fail over the years?
>
> Thanks
>