Fire alarm power supply.

[Dinnertime Dave]

I have always been told that in flats the fire alarm should be taken from the landlord's supply, not the residents.

I have told by M&E guys that if you do this then it goes against other guidance on emergency isolation of circuits in the event of somebody getting an electric shock, as the consumer unit may be some distance away. Apparently, the isolation point has to be within a certain distance.

Can anybody confirm this?

[nearlythere]

I have always been told that in flats the fire alarm should be taken from the landlord's supply, not the residents.

I have told by M&E guys that if you do this then it goes against other guidance on emergency isolation of circuits in the event of somebody getting an electric shock, as the consumer unit may be some distance away. Apparently, the isolation point has to be within a certain distance.

Can anybody confirm this?

Why can't you have an isolation point outside each flat regardless on how far the consumer unit is away?

[Bill J]

Dave,

Assuming Part 6 and a fire alarm system within the flat, rather than protecting the common parts.

The Electrical supply should be part of the Residents Supply, but should not be connected via a keycard meter. If a panel is included, i.e. Grade A, B or C, then a dedicated supply to the equipment, and not through a common RCD. Local Isolation adjacent to the Panel.

If it is a system without a Panel, i.e. Grade D (Mains Smoke Alarm with Battery Back Up), then it does not have to be a dedicated circuit, (although encouraged), but can be supplied from local lighting circuit, which actually assists as the user is more likely to become aware if the circuit has failed.

I will never install a Grade E (Mains only, no Battery Back up) system, so no likelihood of that ever becoming an issue.

Happy to be corrected, and I know I have simplified it, but I am a simple man.

Bill

 

[David Rooney]

As Bill says....

I would always take the mains supply to smoke alarms from a local circuit - either off the lighting or direct from the local fuse board - off the "live side" and separately fused if a key card or similar is in use.

Otherwise there could be all sorts of implications if you turn the fuse board off and the smoke alarms remain live because they're fed from a landlord's supply.

You could also be introducing a different electrical phase into a flat which means 415v between a smoke alarm and a light fitting (or anything else electrical in the flat) which could certainly make your hair curl.   

[colin todd]

Suppers, you are right and you are wrong, but mostly you are wrong.

You may be thinking of the rec that, in an HMO, if you have pre-payment meters in each unit of accommodation, the supply to the smoke alarms in that accommodation should be from the landlord supply.  No need for this in blocks of flats generally.