NESS 16D PIR locations

Hi there,

I am wiring up the new house this weekend, and will also be wiring up for the alarm system. My question is whether it really matters whereabouts in a room that I place the PIR's in relation to potential problems caused by heat / cold / breeze from windows / door etc. I just don't want to assume that I can put the PIR's "anywhere" in the room, only to find out they should be so far away from windows / doors etc.

I also have a need for some reed switches in location such as external door into the garage, garage panel lift door, courtyard sliding door etc, however I was warned off using PIR's in place of reed switched due to the fact that if someone simply smashes a window to enter the house, this won't actually set off the alarm - due to the fact that the reed switch hasn't been tripped. Does this sound feasible?

I can easily run the figure 8 cable from each PIR location back to the alarm panel location, with the view that I can then get an installer to come and connect / program the panel. Has anyone had any luck with this type of arrangement. I am waiting for a reply from two alarm installers, but have been waiting a while now and had no response yet. Once I get an idea from others I can then put this idea to the alarm installer.....

 

Timmmm

I can't give you specific advice on alarm panels but will offer some general advice which I accept no liability for

yes, it does matter. Try not to point PIR's towards windows or external doors with glass. If you have no choice but to point them towards windows, point them towards windows that don't get direct sunlight (ie south facing windows)

Only in part. Reeds can be used for more than just intrusion detection. Not all bad guys want to make noise. If they can avoid smashing a window, they will. Reeds are great for night-time security where you can protect windows and doors, but leave the house free for people to move around. You can use a combination of reeds and PIR's whereyou need to trip one or both zones. This is handy for delays on entry doors when you setup what is called a 'hand-over' zone. This will give a delay on the PIR if you come through the door, but if you don't, the zone will trip instantly. Reeds are also handy for triggering lights on entry.

Panel lift doors use a different type of reed (generally called a heavy-duty reed)

(Concealed) Reed switches need to be drilled into the timber-work too at frame stage. Worth doing a little more research on this aspect.

Figure 8 is no good for PIR's. You need at lest 4 core security cable to both power the PIR's and get the signal back to the panel. Your alarm installer may allow you to do this. chances are, you won't save much money though. You may get a neater install though

Cheers

 

Totally agree, although if you want to connect the tamper switches in the PIRs, you'll need to run 6 core for most panels, although some you can get away with 4 core when using EOL resistors.

And you'll definately get a neater install, 99% of the systems I've seen installed by security guys have some of the dodgiest crap of an install I see around, they just dont give a **** about being neat, and they usually have no knowledge about best practices in other cabling fields, so they dont bother doing things to a standard that most other multi-discipline guys will do it to.
It especially ****s me off when they just run cables directly across false tile ceilings, as several times I've seen these cables accidently cut by others or chewed by mice. It's not exactly rocket science to suspend the cables like every other damn cable in the ceiling cavity...

rant over.

 

Thanks for your replies - It's hard to believe that there are so many people willing to give free informative advice. I can only hope that one day I can make a valuable contribution.

I have one further question however - I have an abundance of CAT 5 cable and was wondering whether it is suitable for the operation of the PIR's - reed switches etc?

Any thoughts????

Thanks,

timmmmm

 

Hi Tim

You need to use stranded cable for security.

Cheers

 

reeds you can use fig 8, PIRs from AS has to be stranded so cat5 is a nono