Sunday, 1 September 2013

Five Most Common Reasons Alarms Develop Faults


Also it should be remembered that in a full security alarm service, there are other tests which have not been mentioned in this article and it’s always advisable to have your alarm serviced from time to time by a qualified engineer.

Absolute can do a simple service from just £29.
Call Chris on 0151 4762421 or 0800 8600316 or 07973 921680

You can guarantee that virtually every single time I am called out to repair a burglar alarm, it is one of  five faults that usually occur

Probably the biggest fault that you get on a security alarm which has been installed for over five years, or a system that has not had a service in that time, is the internal battery on the panel will be completely dead. Sometimes this has caused the 1.2 AMP on the circuit board which is in line with the trickle charger to blow. This means there is no rechargeable current going into the battery any more.

The second biggest fault I would think is that the tamper circuit on the control panel has gone open-circuit. The Tampa circuit consists of a loop of wire that runs throughout all the passive infrareds, shock sensors and magnetic contacts in the building. It is one big series loop and this will often have gone open-circuit and this will cause the internal tamper sound to have occurred on the control panel. When the customer puts in their user number to stop the sound, it does extinguish the internal sound but it usually leaves an LED lit on the panel saying tamper and the system will not work again until this circuit has been closed.

The third most likely fault is with the personal attack circuit which is once again a series loop of wiring that goes out to the siren box running through a micro switch that closes when the lid goes down on the self-acting siren box. The micro switch is sometimes faulty and with this circuit it’s like the tamper circuit but the difference being that when it goes open circuit it sets the full alarm system into activation rather than just the internal tamper sound. The repair is to replace the tamper switch in the siren box outside.

Probably the fourth most recognisable fault with a burglar alarm system caused by the fact that the external self-acting siren box is mounted on the wall outside and exposed to the weathering elements. Inside the self-acting siren box there is a printed circuit board that in the older units could be affected by damp conditions after a number of years. In the new up-to-date units they usually enclosed this printed circuit board in its own self-contained plastic box to protect it from damp.

The fifth reason that a hardwired security alarm system can stop working is quite simply because one of the various small 1.2 amp glass fuses on the main printed circuit board inside the control panel. You just need to physically check these, but it can be difficult to see if the very fine fuse wire is blown. Once again a multimeter with the continuity tester is the reliable way of checking.

These are the simple things that can go wrong on a small domestic alarm

Higher class systems don't just use a loop circuit, they have end of line resisters of two types, other systems have ID line resisters, otherwise known as biscuits.

Absolute can do a simple service from just £29.
www.alarmsinmerseyside.co.uk

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