31-01-2020
This month in our Technical Focus, Steve Snoddon, Joint MD of Diamond discusses Manual Call Points, which are one element of Fire Detection and Alarm Systems.
Q: What are Manual Call Points?
A: Manual Call Points are devices for the manual initiation of an alarm. They are used to allow building occupants to signal that a fire or other emergency exists within the building. They are usually connected to a central fire alarm panel which is in turn connected to an alarm system in the building.
Q: What is the purpose of a Manual Call Point?
A: Manual call points help to ensure a timely evacuation of people in the event of a fire.
Q: Where should Manual Call Points be sited?
A: Manual call points need to be prominently sited, readily distinguishable from non-fire alarm call points, and distributed such that, from any point in the building, it is impossible to leave the storey or building itself without passing one. They must also be sufficient in number to ensure that the time between the discovery of a fire and the alarm being sounded is as short as possible – the 45m rule stipulates that no one needs to travel more than 45m to reach an MCP (measured along the actual route of travel) – 45m rule reduces to 25m if the person likely to actuate the alarm has impaired mobility or if rapid fire development in the area is likely due to processes in operation, or in high risk areas such as a kitchen or a paint spraying workshop.
Q: What changes to Manual Call Points were brought in under the 2017 revision of BS5839-1?
A: Manual Call Points must now be Type A, which is defined in BS EN 54-11 as follows “Type A Direct operation: A manual call point in which the change to the alarm condition is automatic (ie without the need for further manual action) when the frangible element is broken or displaced.”
There is also now a requirement for a plastic cover to be fitted on MCPs. The purpose of the plastic cover is to reduce the risk of false alarms in buildings with large footfall or a potentially malicious activation. Whilst it is not necessary to retrospectively apply this to MCPs, it is considered good practice.
Diamond Systems offer CPD accredited training on aspects of Fire Detection and Alarm Design, including MCPs. For support, or to request CPD training for your design team, email design@diamondsystems.co.uk.
