max number of sensors in one zone

[Guest amc]

hi

is there a maximum number of sensors that that you can have on one zone, i,e 6 vibration sensors

thanks

amc

[Deltaseven]

It really is not worth taking shortcuts like putting more than one detector on a zone, unless you have absolutely no choice. As mentioned above, you must make sure that you use latching devices (so that you can tell which one has tripped).

It makes it harder to track down a fault - even if the devices latch, if you have a cable fault or a bad join inside a detector you can spend ages tracking it down.

If you must put more than one detector on a zone, make sure that you run sufficient cable to support the detectors (eg, if you are running 3 powered devices on one cable, the power cores must at least be doubled) (that goes for ID systems too - but from your question, I don't think that will affect you!)

D7

[Guest amc]

for three or four sensors on one circuit do you think doubling up of power core necessary

Yes, 10.

And PIRs / vibs must be latched.

Contacts dont obviously. I think most installers now would take BS4737 as a minimum and not bother with the above, seeing as panels with loads of zones are so much cheeper than they were years ago.

20827[/snapback]

[Service Engineer]

do you think doubling up of power core necessary

That depends on the lenth of the cable run, and the quality of your cable. Most detectors dont use much current, usually between 10 and 15mA.

[Guest pkh911]

If your a decent engineer.

RULE of THUMB

1 device 1 Circuit

Then you have NO PROBLEMS should a fault occur

[Guest]

If your a decent engineer.

RULE of THUMB

1 device 1 Circuit

Then you have NO PROBLEMS should a fault occur  

27367[/snapback]

This guy is full of wisdom

[bellman]

If your a decent engineer.

RULE of THUMB

1 device 1 Circuit

Then you have NO PROBLEMS should a fault occur  

27367[/snapback]

Fully agree...

makes the Service Eng's life much easier when things go wrong.

Also in line with Richl, I double up the neg, especialy to data devices such as RKP's.

Regards

Bellman