meter cable

[darren1971]

IF THE CABLE RUN FROM METER TO CONSUMER UNIT IS APPROX 7 METERS WHAT SIZE CABLE IS REQUIRED.

 

[breezer]

please note item 6

 

[Big_Spark]

Darren, firstly lose the caps lock, that is considered shouting.

To answer your question we need some information;

Why is the distance from meter to board 7 meters?

Is this existing or have you moved it?

If existing what cable fed the board before?

What size mains supply do you have (60A, 80A, 100A, 125A)


Generally the link from meter to board should not exceed 2 meters if using double insulated tails. If the run is greater than this, then a different type of cable should be used, generally this will need to be SWA (Steel Wire Armoured) as the largets Twin and Earth (T&E) cable available is 16mm. The usual head is 100A, thus you need to have a 25mm cable, but depending on the load your installation runs at, you may need to consider 35mm (although this is unlikely).

The SWA will not terminate straight into your meter, so it would need to be terminated in a steel box to ensure it is terminated correctly, ideally your DB will be steel too. Either way the integrity of the Earth must be maintained from supply to DB, this can be done with the armouring of the SWA, but you may wish to consider the purchase of 3 core SWA so that the third core is your Earth. All connections must be tight, as tight as possible without damaging the screw heads.

please note item 6

Helpful as ever breezer

 

[darren1971]

The supply is for a new build property.The reason it is 7mtrs is that the consumer unit is located under the stairs.As the run is so long do i need to put an additional fuse between meter and consumer unit.Can i run the cable through ceiling void as floor coprises of a beam and block floor.

 

[ChrisRogers]

if its a new build why dont you just have the meter on the wall with the CU?

 

[darren1971]

I thought that all meters now had to be sited externally.

 

[Lectrician]

Most suppliers want the meter outside when possible. This is not a requirement.

Different suppliers have different rules, WPD allow any length tails, sized accordingly, with need for additional isolators or overcurrent protection.

There used to be the '3m rule'. This was derived from bs7671. The service head is commonly 100amp. The average house had 4 fuses (30, 30, 15, 5) Totalling 80amp. 16mm would be fine for this current, but was headed by a 100amp fuse. This is why they liked to see 3m max tails.

Contact your supplier/DNO/Rec. They will advise as to their requirements.