Tamper light

[Jattberik]

Please Can Anyone Help My Alarm is a C&k Securitech For Some reason Every now & then tamper light is on & alarm is going off yet no pir has triggered can you help

 

[breezer]

the tamper circuit is on 24 / 7, it protects all cables, devices and sounders, have you moved, adjusted or redecorated recently?

 

[Jattberik]

no. nothing has been done.

somebody told me that it was the back-up battery in the main circuit box ... but i have changed that and it has made no difference ...

 

[breezer]

In that case you have either a loose cover or a cable is slightly damaged, either use a meter to check resistance of cable, or call an alarm Co, NOT an electrician

 

[securespark]

Could be a dicky spring on bellbox tamper, or dicky tamper anywhere.

If you know how to use a meter you can test all the individual tamper circuits to see if you can find an intermittent reading.

 

[Jattberik]

Thanks I Think i have found problem one of the sensor covers had come loose & this was the cause THANKS AGAIN

 

[BR]

Is the tamper just a single core in the alarm cable which if cut will put the panel into alarm? So if you knew for example that the tamper was purple, and cut all other cores in the cable except purple, you could disable the device.

Is this true, or have I got it completely wrong?

 

[breezer]

Is the tamper just a single core in the alarm cable which if cut will put the panel into alarm? So if you knew for example that the tamper was purple, and cut all other cores in the cable except purple, you could disable the device.

Is this true, or have I got it completely wrong?

No. I shall explain
99% of all alarm detectors are "normally closed" so by cutting the power to the detector (you said cut all other cores in the cable ) the detector will not have power so it will go open circuit so depending on state of alarm (set or unset) it will either activate, or unable to set, the same is also true of the actual circuit wires.

The tamper is also a closed loop so it too is two wires (so for example purple and pink) so cutting this will break the loop and it will cause the panel to go into alarm.

a single wire IS used for the "bell" in that it has a minimum of 4 wires

+ve supply
-ve supply
Ringer (when voltage is applied it rings)
RETURN (when all tamper switches are closed, sends voltage back to panel

but if you cut the wrong one the alrm will activate and all bell cables should either be inside the protected area or have mechanical protection.

Some alarms use resistors in the detectors (so it only requires supply and two wires) it measures the resistance to determine if.

everything is "normal"
Alarm condition
Tamper condition

 

[BR]

thanks very much for your detailed reply breezer, just out of curiosity, if one managed to trip the mains supply and disconnect the back-up battery leads without coming in contact with sensors etc. is the alarm useless.
I know that 'spring switches' are used on some of the boxes etc. so this would be very difficult, this is really a theory question.

Will a loss of battery and/or mains trigger the alarm?

 

[breezer]

obvioulsy the panel battery is there to take over if the mains fails (it is required to last for a minimum of 8 hours, but that is to soon change)

The panel and or power supply MUST be fitted with an anti tamper device (usually micro switch) assuming you could NOT operate these, and you did turn the mains off, and remove the battery, the bell then activtaes as it too has a battery, this is primarily so that if any one pulls the bell off the wall it activates, even when the cable to it has been cut.

In reality what happens is a carpet fitter cuts the cable inside the property and the end user can not stop the bell form activating no matter what they do

I mention bell as figuritvly spaeking now days it is nusually an electronic sounder

 

[BR]

i know i'm really starting to annoy you with questions but a final one.
I am thinking of a fire alarm panel like this:

Key Switch Normal / Arm Controls
4 Buttons Reset / resound ......
silence sounders
evacuate
(something else)

1. If you activate key switch and press evacuate, will this put the panel into a full state of alarm?

2. Lets say a call point is operated by mistake, so you go to the panel and press 'silence sounders' then the panel starts beeping, if you press reset the sounders go off again, so how do you 'reset' the panel without replacing the glass, is this possible, what is actually activated on the call point is a button pushed in that simply has to be ''pulled out again'' or what.

Thanks again,
Bryan.

 

[breezer]

i know i'm really starting to annoy you with questions

No you are not annoying
1) Yes

2) so how do you 'reset' the panel without replacing the glass, is this possible
unlike an intruder alarm, a fire alarm must give an indication that something is wrong all the time (burglar alarm can be silenced) so the only way to silence it is to restore it back to its origonal state , i.e put in a new glass

2A) what is actually activated on the call point is a button pushed in that simply has to be ''pulled out again'' or what.

most "call points" like

have a micro switch at the top centre which is depressd by the glass, breaking the glass releases the micro switch, there is also a test point, that when an apropriate device is inserted it drops the glass down to operate the micro switch

The origonal "gent" call point did have a button (not microswitch) that did indeed pop out, but as you had to find something to break the glass with and risk cutting your appendige some one invented the call point as previously mentioned, to test it was a "performance" you had to undo an allen screw (almost 1 inch long) then press a button inside

Also unlike intruder alarms fire alarms are normally open, with an end of line resistor (some panels have a diode) which means that to make an adition you can not "spur" off as you would a socket but you have to keep the continuity of the "ring"

Fire alrms are so called becuase it sees fire, intruder alrms are so called because they see some one coming intruder window

 

[BR]

Thank you for your reply breezer. It's a topic I always found interesting and as FF we were only shown how to activate and silence the alarm. Hence by lack of knowledge! I actually spent two summers working for GENT as a youngster about 14/15. It’s surprising what you remember, but things have changed!

 

[securespark]

Oh, I get it........."Intruder window."

Ha, ha, ha, ha, ha, ha, ha, ha, ha........!!

 

[Kimba]

Is the tamper just a single core in the alarm cable which if cut will put the panel into alarm? So if you knew for example that the tamper was purple, and cut all other cores in the cable except purple, you could disable the device.

Is this true, or have I got it completely wrong?

Nearly all alarms now days have resistance sensing, so you would need to cut and rejoin the loop with the correct resistance link within the time it takes for either the analogue (or probably now digital) watchdog circuitory to notice a change (fractions of a second).

Also bare in mind:
1. Although most installers wire the tamper loop as the brown and orange pair, the detection circuit as the yellow and blue and the power as the red and black, there is no SET standard. Also in ID systems the iD loop carries both a tamper and detection circuit signal at different frequecie.

2. Any wiring for an alarm system would be in an area protected by some form of detector, so unless you where to sabotage the alarm whilst it was unset, to return later when the alrarm was on, you couldn't get access to the wiring to cut it.