Seprate earth

[fxsteve]

Hi Guys,
I am planning to supply a PV array with a Separate 2 way consumer unit.

1. The circuit will be protected by a 63A 30ma RCD,with a dedicated 16A MCB
2. There is an double pole isolator next to this CU
3. Then there is the meter.
4. Then there is another Isolator next to the Inverter in the loft Area.
5. All of this is run in 4mm T&E
6. The separate 2 way cu is supplied from a 100a Henley block,with 25mm double insulated meter tails.

My Question is :-

I have cut into the main meter tails (after isolating from the main 100A supply obviously) and installed a 100A Henley block with double insulated 25mm Meter tails in to the RCD on the new 2way CU.

The PV dedicated circuit is supplied from a 16A MCB,this circuit is run in 4mm T&E.

I have terminated the MCB and the RCD correctly.

My real question is...Should of i ran a separate earth from the MET or the Earth bar from the original CU to the new 2 way CU eart bar i have installed.

Sorry if elementary question,can not see why this circuit needs an earth.

First PV install

Cheer Guys

FX

 

[JulianC]

How have you earthed the inverter?

 

[fxsteve]

Through the 3 core flex supply by the Sunny boy.

Im a bit confused as i was under the impression the inverter had its own isolator internally

 

[JulianC]

Sorry, you've lost me a bit. The inverter is a class 1 device and needs an earth/cpc. It sounds like you've connected this at the inverter plug via your three core flex. Presumably you've then connected this to the earth of your twin and earth at your isolator and carried it through back to your consumer unit. In which case have you simply terminated it in the earth bar of your new CU, which is itself not connected to earth?

Hint: your new CU needs an earth!!!

 

[BruceB]

Sorry if elementary question,can not see why this circuit needs an earth.

Every circuit needs an earth

Look at 411.3.1.1 last sentence

"A circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point."

Regards
Bruce

 

[malcolmsanford]

Can I ask also why did you supply the 2 way CU with 25mm^ tails, there is no problem as such, but would have made life a lot easier coming out of the Henley with smaller.

 

[fxsteve]

Did not have 16mm tails on the van and CEF can take ages in the morning to get gear (as we all know) so i just used the 25mm,if i did have 16mm believe me I would of used them

Yer,thanks for the reminder of the Regs Bruce.

I Think ive got a bit too involved with the whole "PV Array" thing,its my first.

Your right,thanks for that,I was over thinking the whole thing tooo much and posted this before ive had time to really sit down and think on a bit.

I reckon were all a bit guilty of doing that sometimes lol

It is,in the end,just a circuit

So thanks for that lads you all gave me clarity in a moment of doubtless and a quick re-focuser

Cheers.

Oh.. before I go.

Would any of you agree that if a property has an older type of meter fitted (Wheel Type) that when the wheel goes backwards (some go backwards not all of them) it is classed as theft and needs changing ?

I would get it changed anyway,but is it classed as theft ??

But extreme but im sure it is you know ?

would be great if any one could clarify this

Thanks Lads

Steve

 

[SimpleSimon]

If by turned backwards you means someones fiddled with it than yes they can be prosecuted for it as it's private property of DNO but I dint know if it's classed specifically as theft.

 

[edexlab]

If by turned backwards you means someones fiddled with it than yes they can be prosecuted for it as it's private property of DNO but I dint know if it's classed specifically as theft.

most FIT Forms ask you to ascertain whether or not the meter winds in reverse and if it does they'll change it

 

[BruceB]

Would any of you agree that if a property has an older type of meter fitted (Wheel Type) that when the wheel goes backwards (some go backwards not all of them) it is classed as theft and needs changing ?

It is not theft because electricity does not fall within the normal definition of property. There is a more specific offence of Abstraction of Electricity within the Theft Act that it might come under, but to be guilty of that I expect you have to do it deliberately. Theft cannot be accidental, there has to be intent. Done deliberately, rather than by accident or ignorance, allowing a meter to run backwards would probably be a criminal offence. And the offences of Fraud and Conspiracy are probably also relevant if you helped someone do it. But I am not a lawyer.

Regards
Bruce

 

[Ramjam]

on the G83/1 notification you need to complete the boxes stating the make and model of the meter and the serial number. This is so that the DNO can confirm that the type of meter fitted is compatible with an SSEG. Don't worry about it, it's their responsibility to check.

Don't waste time thinking about it, fit the kit, complete the form and move on!

 

[mmccx]

Can I ask also why did you supply the 2 way CU with 25mm^ tails, there is no problem as such, but would have made life a lot easier coming out of the Henley with smaller.

does it not say in the on site guide that all tails must be a minimum of 25mm to supply a new consumer unit?

 

[moshun111]

It's a safety thing. With that much power in the area, the 'step' and/or 'touch' potential (see links) if a ground fault occurs can be lethal.

 

[malcolmsanford]

does it not say in the on site guide that all tails must be a minimum of 25mm to supply a new consumer unit?

The OSG is a good guide but it is just that a guide. If you look at the last part of section 2.2.3 in the guide it does say that the final decision of the tails size is the DNO. So the tail sizes will govern what protection device the DNO will fit, if you fit 25mm tails then in the future the DNO will fit a 100amp fuse if 1 the system can take it 2 the customer pays for the upgrade.

If you doing a CU change and the protection device is a 60amp then there is no problem with you fitting or leaving the 16mm tails, it would just mean the DNO will not fit a larger protection device until the tails are changed to 25mm.

I asked here is becasue the OP was saying that he was going to henly block the main tails to fit a small single way board, for a 16amp PV installation and was using 25mm tails. In this case there is a good chance you can use regulation 434.2.1 and use much smaller tails, perhaps as low as 6mm, but definately 10mm.

 

[edexlab]

The OSG is a good guide but it is just that a guide. If you look at the last part of section 2.2.3 in the guide it does say that the final decision of the tails size is the DNO. So the tail sizes will govern what protection device the DNO will fit, if you fit 25mm tails then in the future the DNO will fit a 100amp fuse if 1 the system can take it 2 the customer pays for the upgrade.

If you doing a CU change and the protection device is a 60amp then there is no problem with you fitting or leaving the 16mm tails, it would just mean the DNO will not fit a larger protection device until the tails are changed to 25mm.
I asked here is becasue the OP was saying that he was going to henly block the main tails to fit a small single way board, for a 16amp PV installation and was using 25mm tails. In this case there is a good chance you can use regulation 434.2.1 and use much smaller tails, perhaps as low as 6mm, but definately 10mm.

In the original post he states a 100 A supply as I've always understood for this size incomer 25mm tails should be used (approx 114 amps) for 100A main fuse ,16mm has a rating of around 87 amps clipped direct .
ie in the op 100A main fuse to henley block separate tails to 63A 30mA Rcd