Euro standards in close-up

Welcome to the sixth and penultimate instalment in the series. Firstly an update on the implementation of the EN50131 series. The date for implementation of EN50131 remains September 1, 2003. However, agreement has been reached to permit the use of existing UK standards for a limited period after this date. As a result, systems may be installed in compliance with the European standards as specified in PD 6662 or in accordance with existing UK standards. A statement to this effect has been agreed between ABI, ACPO, BSIA, NSI and the SSAIB.

In this article we will continue to look at TS 50131-7. For those who missed last month's article, TS50131-7 Application Guidelines for intruder alarm systems, includes recommenda-tions relating to the design, installation, operation and maintenance of intruder alarms and is similar to BS4737 part 4 in this respect.

When conducting a risk analysis, surveyors will need to consider the minimum level of supervision required. In the context of TS 50131-7 "super-vision" relates to the extent of the detection to be provided, e.g. detection of the opening of doors and windows, movement or the penetration of walls etc, which should be consistent with the risk associated with the premises and its contents.

The Application Guidelines provide recommendations but do not include compre-hensive proposals. While the standard provides a reasonable guide to what type of detection might be appropriate, it is the responsibility of the surveyor to make a decision on the requirements.

The table provides guidance regarding the minimum levels of supervision, and by grade, gives recommendations relating to the design of system with regard to the type of detection. As you can see, the range of supervision recommended varies significantly from grade 1 to 4. As this is only a guide surveyors should consider the suitability of detectors for differing intrusion methods. For example, the guidance table does not necessarily recommend that all doors should be protected, only those that are considered to be a risk.

Setting of a system can be initiated within the supervised premises and completed outside the premises, or setting can be completed outside the supervised premises using appropriate ancillary control equipment. If the system is not in a normal condition when setting, e.g. all detectors in a normally closed condition, the system should not set. In certain circumstances the system may allow limited conditions preventing setting to be overridden.

Similarly unsetting of a system can be initiated outside the supervised premises and completed within the premises, or can be performed outside the supervised premises using appropriate ancillary control equipment. As such, recommendations regarding setting and un-setting are very "open" compared with BS 4737. However you should remember that BS EN 50131-1 requires systems to be designed to minimise the possibility of false alarms occurring during setting and unsetting.

Finally, for systems including an entry route, only 45 seconds is allowed to complete unsetting. This is apparently a deliberate attempt to ensure entry routes are kept as short as possible.

All mandatory indications are required to be together in at least one location. Indications can be repeated throughout the premises in whole or part. Where active detectors are used, i.e. movement, vibration etc, indication should be available for each detector. As in BS4737 mechanical detectors, e.g. magnetic contacts, can share a common means of indication, up to a maximum of 10 devices. Individual detectors can be grouped for control or other purposes, providing, for example, group isolation and part setting/unsetting.

It is important that all system components are installed in accordance with manufacturers' instructions. If a component cannot be installed in accordance with given instructions, advice and guidance should be sought from the manufacturer or supplier. As you will have read in earlier articles, you will need to select components with the correct environmental classification.

The installer will need to conduct a technical survey in order to ensure that the intruder alarm system meets the requirements of the system design proposal. The surveyor will usually have completed this. The objective of the technical survey will be to establish that the system provides the performance specified in the system design proposal and to consider issues which might adversely influence the reliable performance of the system.

Significant areas that should be taken into consideration are:

• Setting and un-setting operations

• The type of setting and unsetting proposed should be checked to ensure the possibility of generating false alarms is minimised and is appropriate to the type of premises.

• Selection of components

• The components should be checked for positioning to provide optimum performance, and siting should be as per manufacturers' recommendations.

• Interconnections

• Consideration should be given to the effect local environmental conditions might have on the type of interconnection specified.

• Amendments to system design proposal

• Any change required to the original system design proposal should be agreed with the client and most importantly, recorded.

Depending on the size and complexity of systems you will need to consider preparing an installation plan. The installation plan will be based on the system design proposal and consider issues identified in the initial survey. It will provide information on a number of issues such as: the location and siting of each system component, details of interconnections, cable types and routing, setting/unsetting operations, circuit configuration, warning device delay and duration periods. The plan will also need to include an equipment schedule.

Installation of intruder alarm systems should be undertaken by personnel with the necessary training and experience, together with the use of correct tools. The installer should also hold an appropriate qualification. It is important that the system is installed and configured as defined in the system proposal. If there are any deviations they must be agreed in writing with the customer.

On completion of an installation, an inspection of the system is required to ensure that the installation meets the requirements of the system design proposal and the installation plan (if one has been prepared).

The performance of each detector is to be tested and compared with the requirements of the system proposal and installation plan, if one has been prepared. Any changes to the system resulting from the functional tests must be recorded and included in the "as fitted document". The "as fitted document" should be an accurate record of the installed system that includes information relating to the installed equipment and its location. This document should also be available for service and maintenance personnel.

The installation company should provide the client with a certificate of conformance stating that the system has been installed in compliance with the "as fitted document". Further, when the intruder alarm system, or any components installed, are claimed to comply with any legislation, regulation, and whether National or European specifications, any such claim should be included in the certificate of conformance.

Next month, in the final article on EN 50131, we will look at the standards required from September 1, 2003 and additionally consider the implications of PD6662.