Design and Installation

INSTALLATION FOR NEWSAGENT/SHOP

In this example we shall use devices that have been discussed in previous sections to design a system for a small newsagent shop. (refer to “shop plan” at end of this chapter.)

Firstly decide what detection devices are to be fitted to the perimeter. The two front windows can be fitted with foil tape as well as the glass sections of the front door. Also on this door we will need a contact to detect any entry by opening. As this door will be the way in and out of the shop for the operator, then this contact should be wired to the exit/entry zone.

The rear door to the store, we will assume, is a solid door with no glass sections and can be fitted with a contact.

All the perimeter entry points have now been covered which leaves the internal doors. Should an intruder gain entry through a point other than those covered, then, by fitting contacts to the two internal doors, any movement between these areas will be detected. Finally, since this is a shop, it will have relatively large amounts of cash, so a personal attack button should be fitted beside the cash desk.

Starting the installation 

If you place the transparent sheet marked “overlay A” over the plan of the shop you will see the location of the detection devices as well as the location of the control panel and the bell box.

Before any work is done on an installation it is best to decide where the control panel is to be located as this is where all the wiring will terminate. Two other points to bare in mind when locating the panel are: it should not be too far from the final exit door. (This is to keep the exit/entry time to a minimum.) Also it should be near to a 240 volt supply

Alarm Zones.

For this installation the two zone key operated panel is to be used. We now need to decide which detection devices are to be connected to which alarm zone. The front door contact is connected to the exit/entry zone as this is the wav in and out the premises. The personal attack buttons are terminated at the p.a. Zone so we are now left with two alarm zones.

There are a number of options we could take but for this example we shall put the front of the shop on zone one. That is: the foil tape. (the contact is already on the exit/ entry zone).

The two contacts on the internal doors can be put on the second alarm zone, along with the back door contact.

Our zone configuration now looks like the following:

This should be written out and a copy given to the operator for their reference. A copy should also be left inside the control panel for the engineers reference oh future maintenance visits.