scope:

Introduction

This standard applies whenever it is necessary to disconnect or isolate automatic heat or smoke detection devices (with or without automatic suppression) in order to avoid the devices being activated by dust, heat or smoke from nearby work.

If the station is governed by the Fire Precautions (Sub-Surface Railway Stations) Regulations 1989 (the 'sub-surface' regulations) and the isolation is to take place during traffic hours, then it will be necessary to arrange for a temporary exemption from the sub-surface regulations. A temporary exemption is not necessary if work takes place during engineering hours only.