Mains electrical supply in non domestic premises

[Davash]

Does anyone know what the requirement is for mains electrical supplies in non domestic premises to be enclosed with Fire resisting doors (and what duration)and marked with electrical warning signs.

Davash

[kurnal]

There is no specific general requirement for this.

In some circumstances it is appropriate- eg oil filled switchgear, substations, transformers, or if the electrical switchroom opens onto a protected route eg corridor or staircase. If oil filled switchgear is present then 1 hour would be the norm, otherwise half hour doors would normally suffice.

Often there is a need for doors for security reasons, eg to prevent unauthorised access.

[Davash]

Kurnal,

Thanks for your quick reply, 30 minute doors was on the lines i was thinking. Would this apply if they were located in a small cupboard?

Davash

[kurnal]

Depends where the cupboard is, how big it is and what it contains. If its in the foot of a single staircase building or in a hotel bedroom corridor  or is big enough to contain other fire risk or indeed if the electrical installation it contains is significant (ie much more more than a meter, company fuse and small distribution board or consumer unit)  it may be worth putting on a couple of FD30S.

But small electrical cupboards are not generally a source of particular fire risk and would not need enclosure  with Fire resisting materials as a matter of course.

[Davash]

Kurnal,

Thank you for your reply,the electrical installation only contains incoming supply and circuit breakers and is not situated on any escape route.

Davash

[John Webb]

I would suggest that the cupboard needs to be as small as possible so it can only contain the electrical equipment. The biggest risk comes not so much from the electrical equipment but from the items that may be stored in the cupboard in contact with it. Either these will cause damage (ie broom handles), be flammable (ie some cleaners and polishes) or otherwise may interfer with the electrics or access to them.

[PhilB]

Is there going to be smoke or heat detection in the cupboard? If not I would suggest there is no point enclosing it in FR.

[Davash]

To all who have replied,

I would like to thank everyone for their responses, this is a really professional, excellent site.The electrical installations only cover a small area and at the moment are exposed. From the replies in the forum it would seem that there is no real need to enclose them except for a safety point of view.

Davash.

[AIsRUS]

If you want some guidance on speacialist area fire rating then look at Section 20 guidance note available from any inner london authority. As far as electrical rooms are concerned if you are talking about main ones EDF has their own requiremnts. Wouldn't have said there is much fire load in an electrical installation so don't really see the point in fire rating it? If anything you want to guard it from a fire breaking into it so it doesn't knock out all the electric?

[CivvyFSO]

Wouldn't have said there is much fire load in an electrical installation so don't really see the point in fire rating it? If anything you want to guard it from a fire breaking into it so it doesn't knock out all the electric?

Good way of looking at it, and to be honest, I had never considered that.

But... Since everywhere should have sufficient emergency lighting (or borrowed light) and some form of fire alarm system that doesn't rely on mains power alone, surely something taking out the mains power should not be much of an issue as far as relative persons are concerned?

Although I CAN see the point from a business continuity point of view. A fire in an adjoining corridor/room shouldn't result in the power loss to the whole building that needs to be sorted out before trading/work can continue.