Whilst BS 5839-6 has previously been split into six varying Grades, each outlining the level of protection appropriate for certain properties and their corresponding levels of risk, the new update has altered the six sections, removing Grade B and Grade E, whilst Grade D and Grade F have been split into Grade D1 / Grade D2 and Grade F1 / Grade F2 respectively. Grade C has been revised and its recommendations expanded.
The 2019 grading system is as follows:
Grade A |
Separate detectors, sounders and central control and indicating equipment with back-up power supply that conforms to British Standards BS EN 54. |
Grade C |
Separate detectors and sounders that are mains powered with back-up power supply and central control equipment. |
Grade D1 |
A system of one or more mains powered detectors, each with a tamper‑proof standby supply consisting of a battery or batteries (such as FireAngel’s SM-SN-1 and HM-SN-1 alarm). |
Grade D2 |
A system of one or more mains-powered detectors, each with an integral standby supply consisting of a user‑replaceable battery or batteries. (such as FireAngel’s SW1-PF-T and HW1-PF-T alarm). |
Grade F1 |
A system of one or more battery-powered detectors powered by a tamper‑proof primary battery or batteries (such as FireAngel’s ST-622T, ST-750 alarm). |
Grade F2 |
A system of one or more battery-powered detectors powered by a user‑replaceable primary battery or batteries. (such as FireAngel’s SB1-T alarm). |
Please note: Grades B and E are no longer defined in BS 5839-6:2019. |