Call Sales Free: 0800 9882434
Business Security System Installation and Support.
Call Sales Free: 0800 9882434

CAN WE HELP?Enter your details and we’ll be in touch.

Call To Action
AlertSystems will always respect your privacy.
More information about our privacy policy.

Intruder EN Grade Three


DCDoor Contact (Grade 3)
AM PIRPassive Infra Red Movement Detector, with Anti-mask Capability (Grade 3)
AM DTDual Technology Movement Detector, with Anti-mask Capability (Grade 3)
BGBreak 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.

Grade Three Example


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.

ACEAncillary Control Equipment(eg Exit Terminator Switch)
PACEPortable Ancillary Control Equipment(eg Remote Keyfob)
CIEControl and Indicating Equipment(eg Alarm Panel)
WDWarning Device(eg Bell Box, Sounders, Strobes)
ATSAlarm Transmission System(Signalling System)
ARCAlarm Receiving Centre(Monitoring Station)
PSPower Supply(Power Supply for I & HAS)