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Intruder EN Grade Three


Intruder Grade 3 Example



DC                    Door Contact (Grade 3)

AM PIR             Passive Infra Red Movement Detector, with Anti-mask Capability (Grade 3)

AM DT              Dual Technology Movement Detector, with Anti-mask Capability (Grade 3)

BG                     Break Glass Detector


For a Grade 3 System, Grade 3 type Anti-mask detectors are a requirement.

DD243 still applies regarding overlapping coverage, so PIR coverage must not overlap.

It is acceptable for DT coverage to overlap with PIR or other DT's.



A 45 second maximum entry timer is permitted, with a further fixed 30 second warning period, before an entry (unconfirmed) Alarm is notified to the ARC.

Notification (Sounders and Signalling)

Grade 3 Systems would normally provide an ATS (preferably Dual path) with at least 1 self powered audible WD (SAB/SCB), or 2 remotely powered WD's.

Power Supplies

Grade 3 systems require 24 hours standby when using a ‘Type A' PS.

This can be reduced to 12 hours, providing ‘mains failure' is individually notified to the ARC.


ACE                 Ancillary Control Equipment                               (eg Exit Terminator Switch)

PACE               Portable Ancillary Control Equipment                (eg Remote Keyfob)

CIE                   Control and Indicating Equipment                     (eg Alarm Panel)

WD                   Warning Device                                                     (eg Bell Box, Sounders, Strobes)

ATS                  Alarm Transmission System                                (Signalling System)

ARC                 Alarm Receiving Centre                                        (Monitoring Station)

PS                    Power Supply                                                         (Power Supply for I & HAS)