Bell box location

[John45]

The control panel looks for a particular condition of a wired circuit.
There are two ways to have a default condition.
One is where a circuit is made and so has a specific resistance that can be measured by the control panel. A change in this resistance reading is what indicates a circuit has been tampered with.

So a door contact will have a reed switch where the proximity of the magnet will cause the contact to close and make up the circuit. Therefore either opening the door or cutting the wire will create a resistance change that would indicate an alarm condition.
However you could have a circuit that is always open. ie the magnet keeps the circuit open and the alarm would activate instead if the circuit is made.
That method was the 'old way' of doing things but it was too easy to defeat .

It was a very simplistic way of operation where the alarm was sounded by the contact purely because closing the circuit made a feed for the sounder.
Its how you would make an alarm yourself if geven a battery and a few bits of wire and a speaker.
Pirs however are an always open circuit where activation 'makes' the circuit hence the need for a seperate tamper circuit to detect cutting.

The tamper circuits are always closed also, hence cutting them causes an alarm

 

[John45]

have you ever seen inside a door contact?

Yes I take old systems out daily!

 

[Atilla]

no you dont, please stop trying to make out you`re trade

 

[John45]

Yes I do just get over yourself , three old systems taken out and replaced this week already . . . FFS just give it a rest!

 

[rick85]

Thanks John 45. Very helpful post.

My PIR's are to be put on a tamper circuit so thats cool (as you say they are an open circuit)

I will check the manual to see if my control panel operates a closed circuit for the door contacts.

i thought a tamp circuit was required to identify a specific node that is causing a problem e.g. it an intruder tried to access through the back door unsuccessfully the conroller panel would indicate tamper at the zone the back door magnets were attached to

 

[Atilla]

Where can you get this trunking cant seem to find anything (looking at screwfix b&q online) under 8mm?

newry and eyre will sell something suitable.

 

[John45]

i thought a tamp circuit was required to identify a specific node that is causing a problem e.g. it an intruder tried to access through the back door unsucsessfully the conroller panel would indicate tamper at the zone the back door magnets were attached to

The tamper circuit is seperate to the device circuit so the panel can indicate either an activation of a device or a tamper of the circuit (ie an attempt to defeat the device.)

Both will indicate the affected zone at the panel usually unless the sensors are daisychained together on one zone thus making it impossible to tell which device caused the alarm.

 

[Atilla]

[My PIR's are to be put on a tamper circuit so thats cool (as you say they are an open circuit)

thats not correct - your tampers will be CC too

 

[rick85]

Guys. thanks fo your help. you make a great duo

Following Johns guidance I was lead to belove the zonce circuit for a PIR is open, am I correct or have i misunderstood?

I understand that the tamper circuit is closed. My panel comes with it already closed

thanks

 

[Atilla]

Follow the drawing in the manual, try it all "dry" on the kitchen table 1st if you want but remember if this thing goes wrong at half past one in the morning I won`t be around so make sure you understand it before going live.

 

[rick85]

OK. Ive planned all my wiring diagrams (see image) View media item 16549 . I just wanted to be sure that my door contact did not need to be on the tamper circuit.

For what its worth, you have both mentioned that the tamp circuit is not required (although John was more explanatory with his?)

 

[Atilla]

AKA empty vessel syndrome - anyway - where is your negative conenction in the bottom drawing (or is it my eyesight)

just seen it`s white, is there a reason your using that color combination?

 

[rick85]

try enlarging the drawing? You should then see that the green wire connects to the negative and the cream(white) wire connects to the positive, though this color is very hard to see (sorry)

BTW, im going to go with the star arrangement for my two keypads as this creates the most suitable route for the cables. It would be v.difficult to run a cable between each keypad and daisy chain them.

cheers.

 

[rick85]

just seen it`s white, is there a reason your using that color combination?

I made it up/stole the color combination out of another manufactures guidelined.

although i thought wasnt a single color combnation as set standard to follow?

 

[Atilla]

okay, you know about keeping the alarm cables away from the mains ones etc, etc? beware of 12V type LV lights in the kitchen or bathroom too (handy little hint there)