Re: Failure rate of window / door magnetic sensors

[Matt Ion <soundy106@xxxxxxxxx>]

Given the relatively low cost of simply replacing all the switches, I'd
think that's probably a much easier and more efficient solution...

Roland More wrote:
> 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
>>
>
>