Overriding a PIR with a key switch?

ebee:

or to bypass part of an Intruder Alarm System.

I would think that was quite difficult - switches are not instant, and that ~1000th of a second break should trip most alarms I would expect.

alanblaby:

ebee:

or to bypass part of an Intruder Alarm System.

I would think that was quite difficult - switches are not instant, and that ~1000th of a second break should trip most alarms I would expect.

Depends on intended use. I wasn`t thinking of wiring a switch in para with a PIR detector sited in the same room as an entry device. If used as an entry/exit device it must be outside the protected area.

Back in the old days of intruder alarms (before PIRs even) it was common to have a one zone alar for a whole system. An external keyswitch by the entry door enabled the user to bypass a detector or detectors on the entry route which would enable the user to then disarm the remainder of the system.

Such luxuries as timed entry/exit came later. Similarly one isolatable zone (say bedrooms - example) again came later. Often there were just door contacts and pressure mats, in fact before magnetic door contacts they were microswitches cut into the hinged side of the door frame.

a keyswitch (or a "hidden" switch ) could be employed.

One I did was for a lady with a dog . Typical; terrace house, two main rooms ground floor with PIRs in both rooms. She got a dog therefore wanted sometimes to allow the dog to be in one room only whilst the rest of the alarm was set.

The solution I offered was to put an architrave switch (upside down!) in the pantry on a shelf so it would not be mistaken for the light switch and indeed was slightly hidden even when in the pantry.

I called it her DOG IN switch.

she switched "on" when the dog went out with her and "off" if she was leaving the dog at home..


The funny bit about this particular one was I arranged to do the job a couple of weeks in future at the weekend.

Unfortunately on that day my home town had won a major  football tournament and so they had a "hero" welcome for the team.

Our town was gridlocked and a 10 mins each way journey became something like an hour.

I rang her before I set off then went and did the job.

She was delighted with it and paid me.

I then demonstrated how to use it  when the dog was in.

At that point she informed me that the died had died about a week earlier so she would not need to use it.

Ohh, I explained that if she had told me I would have cancelled her job or postponed it perhaps.

She said she didn`t want to let me down because she`d booked the job with me.

I`d only quoted for a standard quick job at normal rates so only charged her that, no extra for a weekend job and no extra for travelling timed.

I would have rather she had cancelled. LOL.


I called it "Dog is Dead" syndrome.

Years ago my Wife worked at Christmas season in a catalogue returns dept.

When people returned goods they had a slip to write down reason for return.

One day she examined a return , a dog collar or something and the slip with it stating the reason for return said "Dog is Dead" nothing else..

Oh dear, you gotta laugh

 

Will it be okay to override a PIR using a key switch, incase the PIR stops working?