PVC T/E feeding Consumer Units

[Paultrim]

Just on site, first visual of fuseboards noted all are fed in 16mm T/E PVC cables. As the earthing conductor under has to be equal to line conductor at 16mm what code would you gents recommend? EFLIP is satisfactory.

Cheers

Paul

 

[Doc Hudson]

Why do you say the earthing conductor has to be equal to the line conductor? with 25mm tails we do not fit 25mm Earth. and all CPC's in T&E are smaller than the line conductors. Please ref the regulation number that you think it contravenes.

Doc H.

 

[alpha spark]

The earth doesn't have to be equal

If u use 25 mm tails u use a 16mm earth

If u use 16mm tails u use 10mm earth

The earth in a t/e is 10mm so where is the problem

What is the lor of the t/e ?

 

[sb_89]

The earth in a 16mm t+e isn't 10mm. It's 6mm

 

[Paultrim]

Sorry, I'll have a look in my regs shortly they're in my office which i am going back to in an hour, but I thought the earthing conductor at the origin of an installation was equal size upto 16mm then half size 25mm>

 

[sb_89]

Don't think so, it depends on your earthing system. If its Tncs you will need a minimum of 10. If its tns you may be able to use the 6mm in the t+e. you need to check using the adiabatic table.

 

[Paultrim]

GN8, 3.2 either calculate using AB equation or refer to table 54.7 reg 543.1.4 - S<16 = S or 16-35 = 16 S>35 = 1/2S

OSG Table 4.1 clearly shows above equation referring 10mm line 10mm Earthing Conductor for PME which it is.

Sorry chaps I meant 16mm line 16mm Earthing Conductor

 

[alpha spark]

The earth doesn't have to be equal If u use 25 mm tails u use a 16mm earth

If u use 16mm tails u use 10mm earth

The earth in a t/e is 10mm so where is the problem

What is the lor of the t/e ?

Sorry I am mistaken weren't aware of that don't think ever used 16mm t/e

 

[soulman]

I do believe if you calculate using the adiabatic equation that will give you your answer. The tables i believe are a quick reference guide when installing. But i may well be wrong!!! I would code it a 2 on pme with 6mm earthing conductor. 16mm tails 10mm earthing conductor would be acceptable provided no damage to earthing conductor.

 

[Steve3948]

If its 16mm

 

[SLIPSHOD & SLAPDASH]

The earth in a t/e is 10mm so where is the problem

What is the lor of the t/e ?

Thats not correct. The CPC in a 16mm Tw & e is 6mm

 

[steptoe]

ok folks, why are we treating this as tails?

its obviously not,

what size is your OCPD?

can I assume you have a switch fuse prior to the T&E?

might only be 32A , we dont know at this stage, may be 16mm to allow for VD ,

lots more info required my friend, may I call you that?

not hard to know Ive been drinking, I'll call anyone that talks to me on beer my friend..... :|

 

[Sharpend]

There was me thinking you were up early for a walk in the morning air!!

Night steps!