DNO specifies fire-rated enclosure

[knxhome]

The DNO (UK Power Networks) has specified that the duct that will carry the DNO supply to a new SFH has to terminate into a 1-hour fire-rated cupboard.

The duct will terminate in the basement, and the supply will be 3P 100A each.

Which pre-made cupboards would meet the required specs, or if we want to build our own cupboard how would we achieve the required fire-rating? An industrial steel enclosure is not permitted by the DNO.

The cupboard may be mounted either directly onto a concrete wall, or onto a concrete wall that has some internal thermal insulation.

Thanks

 

[Darkwood]

I assume they are talking about the normally white utility meter boxes you find surface mounted or sunk into most new domestic properties... they are of a fibre glass construct i think so would assume have a fire rating to suit your needs but enquire with supplier.

Speak with the DNO they may be mistaken as to the mounting position they may think your fitting an external enclosure as found in most newbuilds ive not heard a requirement to house the cutout and meter in a fire proof enclosure if its internal in the basement?

A cupboard should also suffice boarded with fireboard.

 

[knxhome]

Speak with the DNO they may be mistaken as to the mounting position they may think your fitting an external enclosure as found in most newbuilds ive not heard a requirement to house the cutout and meter in a fire proof enclosure if its internal in the basement?

The DNO inspector has seen the building-in-progress and is aware of the internal location of the meter box.

 

[Darkwood]

Its a new one on me ... may be a regional thing or new requirements - i mean how many cutouts are just screwed to a wall ... i would have a joiner build a cupboard with 1hr fire rating and confirm with DNO if this will suffice and will it require any specific door latch or lock.

 

[colshaws]

try this FireSeal Meter Box Fire Protection / Feeder Pillar, Meter Box Repair, Electrical Enclosures from Ritherdon

 

[Sintra]

If this is a commercial supply then they insist on it being in a fire rated enclosure / room. We normally get a stud wall built around it then a door with intumescent strips etc pretty easy.

 

[knxhome]

try this FireSeal Meter Box Fire Protection / Feeder Pillar, Meter Box Repair, Electrical Enclosures from Ritherdon

Thanks. Looks interesting. However these frames are apparently made of steel. The DNO does not accept a full steel enclose. Whether a steel frame would be acceptable, I would have to inquire.

 

[knxhome]

If this is a commercial supply then they insist on it being in a fire rated enclosure / room....

It is a SFH, private residence.
The somewhat unusual aspects are: 3 phase supply, meter in basement.

.. We normally get a stud wall built around it then a door with intumescent strips etc pretty easy.

Any guidance on how this would meet the 1-hour fire-rating?

 

[colshaws]

Any guidance on how this would meet the 1-hour fire-rating?[/QUOTE]

1 sheet of plasterboard = 30 min fire-rating so double board the stud wall and you have 1 hour.

 

[knxhome]

1 sheet of plasterboard = 30 min fire-rating so double board the stud wall and you have 1 hour.

Thanks. Will also confirm with architect.

 

[mechelec]

Fibreglass meter boxes are not fire rated and give off toxic fumes when exposed to flame. DNO will not allow them to be fitted internally in my area (WPD)

 

[Engineer54]

Never heard of this requirement for a private residence. I'd say 99% of all domestic homes in the UK fall foul of this requirement...

 

[knxhome]

Fibreglass meter boxes are not fire rated and give off toxic fumes when exposed to flame. DNO will not allow them to be fitted internally in my area (WPD)

Thanks, very helpful.

In light of all the advise given here we will go will with a home-made cupboard out of fire-rated material with a door with intumescent strips.