What BS 5839-1 is, the fire-alarm system categories (M, L1–L5, P1–P2), how it differs from domestic BS 5839-6, and the testing businesses must do. A clear UK guide.

What earthing and bonding are, why they’re vital for electrical safety, the difference between main and supplementary bonding, and how to tell if yours is adequate.

How often PAT testing is needed — why there’s no fixed legal interval, the risk-based approach, and suggested intervals by equipment and environment. A clear UK guide.