Size of meter tails

[Ray Tay]

The DNO is only concerned from the meter to the first overcurrent protection devices tat protect their equipment from the consumer unit(s) back to the meter and their fuse. An RCD is not an overcurrent device. mmmmm
So with a 100A fuse it has to 25mm all the way. With a 80A fuse 16mm is fine? I think I am getting there.

 

[EFLImpudence]

No.

DNO only to the incomer - their cut-out and fuse.

Then Energy supplier (who send you the bill) to the meter.

After meter - yours.

 

[RF Lighting]

One RCD protecting the entire installation does not comply with BS7671.

I'm sure others will disagree but I'd fit 25mm² tails regardless of the size of supply fuse.

 

[Ray Tay]

RF Lighting, I have seen many RCD's protecting the entire installation, although only small installations.

EFLImpudence, DNO only to the incomer - their cut-out and fuse? So 25mm to the RCD/incomer and then 16mm after to the CU. Thanks. I still think the fuse should be dropped to 80A to be sure.

I believe the DNOs have different regs to each other. Is that so?

 

[EFLImpudence]

DNO only to the incomer - their cut-out and fuse?

The fuse housing.

So 25mm to the RCD/incomer and then 16mm after to the CU.

No, all 25mm² if 100A.

I believe the DNOs have different regs to each other. Is that so?

Yes, they do but I don't know if cable rating differs between them.

 

[RF Lighting]

RF Lighting, I have seen many RCD's protecting the entire installation, although only small installations.

I've seen people driving at 100 miles an hour on the motorway. Whats your point?

EFLImpudence, DNO only to the incomer - their cut-out and fuse? So 25mm to the RCD/incomer and then 16mm after to the CU.

No. Either 25mm² all the way or 16mm² all the way which ever is required. An RCD doesn't allow you to reduce conductor size.

Thanks. I still think the fuse should be dropped to 80A to be sure.

That's not your desicion to make

I believe the DNOs have different regs to each other. Is that so?

No. They all work to the ESQCR

 

[kai]

A related point - According to LPN, a 0.0225 sq.mm supply cable can continuously carry a load of 100 amps, and service a property with night storage heaters installed. They have uprated countless mains fuses from 60 amps to 100 amps on 0.0225 sq.mm. supply cables without any problems in my area.

 

[ban-all-sheds]

chivers, the quoting Spark may have done that, but it was overkill and not the real point here. One RCD fine here.

Are you ever going to answer this:

Have you actually read 314.1 and 314.2?

 

[ban-all-sheds]

A related point - According to LPN, a 0.0225 sq.mm supply cable can continuously carry a load of 100 amps, and service a property with night storage heaters installed. They have uprated countless mains fuses from 60 amps to 100 amps on 0.0225 sq.mm. supply cables without any problems in my area.

Utter rubbish.

 

[kai]

chivers, the quoting Spark may have done that, but it was overkill and not the real point here. One RCD fine here.

Are you ever going to answer this:

Have you actually read 314.1 and 314.2?

In simple terms it means that a single rcd must never be used at the origin of the installation, to avoid inconvenience when a device trips out - this new requirement was introduced in 1992, before then the regs actually permitted a single main rcd at the origin of an installation.

 

[kai]

A related point - According to LPN, a 0.0225 sq.mm supply cable can continuously carry a load of 100 amps, and service a property with night storage heaters installed. They have uprated countless mains fuses from 60 amps to 100 amps on 0.0225 sq.mm. supply cables without any problems in my area.

Utter rubbish.

See page eleven of this - http://www.powerlogic.com.au/electrical-policies-and-procedures_14_96596857.pdf

See page eighteen of this - http://www.northernpowergrid.com/asset/0/document/1940.pdf

BAN - please get your facts right before posting anything.

 

[ban-all-sheds]

See page eleven of this - http://www.powerlogic.com.au/electrical-policies-and-procedures_14_96596857.pdf

OK.

For once BAN has actually got it wrong - perhaps Arrogance shall not be tolerated any longer..

Please show me where it justifies the utter rubbish you wrote.

 

[EFLImpudence]

a 0.0225 sq.mm supply cable can continuously carry a load of 100 amps

That's about the size of 3A fuse wire.

 

[ban-all-sheds]

Sounds about right.

 

[PBC_1966]

A related point - According to LPN, a 0.0225 sq.mm supply cable can continuously carry a load of 100 amps, and service a property with night storage heaters installed. They have uprated countless mains fuses from 60 amps to 100 amps on 0.0225 sq.mm. supply cables without any problems in my area.

They're talking about older cable with a c.s.a. of 0.0225 square inches, not square millimeters.

0.0225 sq. in. = 14.5 sq. mm approx.