Additional Power Supply

[steve]

Hi,

I'm in the process of fitting an alarm system in my sisters new house - still getting built. I was just wondering how many detectors I can run off the panel, there was an exsting panel in the house which I am using but have read a lot about power suppply units and not sure if I should be using one.

The alarm is going to have one external sab, one internal sounder which also self activates, two keypads and eight PIR's - would you recomend an additional power supply unit?

Regards

Steve

[Guest]

Wots the panel? Have you done a mA reading?.......How longs a piece of string?

[Guest Cerberus NI]

Wots the panel? Have you done a mA reading?.......How longs a piece of string?

....about this long!

[Service Engineer]

As a very rough estimate from your list, I'd say the panel alone will cope ok.

I'm estimating around 350mA in standby and about 700 in full Alarm, but as stated above current draws would be dependant on the equipment being fitted.

Most panel psu's are rated at about 1 Amp, but this is not continuos, just an estimate of the max draw it can intermittantly cope with.

[Guest]

Wots the panel? Have you done a mA reading?.......How longs a piece of string?

....about this long!

wow, then i would advise a 4 amp PSU

That was in reply to Cerberus, Daves about right for a normal panel and set up, doubt you need to add a psu.

[secboy]

As Dave says most panels should deal with 8 pirs but make sure the battery is new and if the property is out in the sticks with power fed by overhead lines and supply prone to loss then i would power the pirs with their own 12v psu and battery that way you will get max hold up of the system in power fail. Paul.

[arfur mo]

for me, any system over 4-5 pirs will have it's own psu for the detection. its not the drain, but a higner possibilty of a short on the supply rail due to a carpet fitter or mice knocking out a many panels.

if that aux fuse also supplies the keypad then a short will blow it and disable the keypad as well, then the user has absolutely stuck - bells sounding, panic mt mannering - run arround house saying oh god what do i do? as no idea what caused it all, and as an installer he can't relay back to you any information other than he/she's going deaf..

for what they cost save the greif

regs

alan

[steve]

its an accord xpc panel, it was fitted a couple of years ago by the dreaded //.National Installer.// and came with the house, I have replaced the battery for a new one. I am by no means a novice and have fitted numerous alarms (of which I can say have been relatively trouble free) but would not know where to start on fitting a psu so if can get away without it I would like to. If I did fit a PSU would I need to run a cable from the PSU to each detector? And I assume that the PSU would need its own power supply from the mains? - I am getting the sparky to do this on the re-wire.

Thanks for your help

Steve

[Guest]

I'm in the process of fitting an alarm system in my sisters new house - still getting built.

is the house not worth splashing out on a proper alarm?

I am by no means a novice.............but would not know where to start on fitting a psu

scary

[arfur mo]

its an accord xpc panel, it was fitted a couple of years ago by the dreaded //.National Installer.// and came with the house, I have replaced the battery for a new one. I am by no means a novice and have fitted numerous alarms (of which I can say have been relatively trouble free) but would not know where to start on fitting a psu so if can get away without it I would like to. If I did fit a PSU would I need to run a cable from the PSU to each detector? And I assume that the PSU would need its own power supply from the mains? - I am getting the sparky to do this on the re-wire.

Thanks for your help

Steve

Steve with all due respect,

you are beginning to worry me, you say this is for your sisters house, which is being built but was installed 2 -3 years ago by the dreaded //.National Installer.// :!:

know i know they can be quick off the mark sometimes, but skyhooks are only an engineers joke and don't exist really (no telling the apprentices), so was the controls stuck to the building plans 2 years back?

the psu powers the PIR and/or Vibration sensors, it's usually mounted next to the controls but not always. a pair of wires is then run into the controls from the psu and the detectors are attached to this 12v supply. your electrician will advise and hopefully fit roper mains supplies.

unfortunately, while not wishing to imply any insults, not not working out the above simple circuit for yourself indicates a very low level of knowledge/understanding to me, so despite your previous experience on simple systems, for you and your sisters safety especially i strongly advise and urg you seek a qualified engineer to assist you.

trust me, nothing seems so simple to those who know as that which is so difficult to those who don't.

regs

alan