British Standards Document
BS EN 54-21
Fire detection and fire alarm systems. Alarm transmission and fault warning routing equipment

https://doi.org/10.3403/30105622U

BS EN 54-21 is maintained by FSH/12. The current release of this standard is:

BS EN 54-21:2006 Fire detection and fire alarm systems. Alarm transmission and fault warning routing equipment

https://doi.org/10.3403/30105622 (published 30/06/2006)

This standard is available from the following sources:

Other historical versions of this standard document also exist: