New sub board for shed swa advice.

[Jcamerz]

Hi guys new to the forum after bit of advice. My family are installing a new shed in the garden and require a lot of power ie few sockets, lights. I am planning of running a swa fed from 32a mcb from the main board to a sub board.
Have a question-
Shall I install the new 32a mcb in the main board on the RCD side or main switch side?
Thanks

 

[bigbob1]

It is a requirement of ESQCR (Reg 24 I believe) for the DNO to provide consumers a connection point to either the network neutral or protective conductor, for connection of the installation earth.
Regulation 25 allows the DNO to refuse this connection only if the installation fails to comply with BS7671, or could pose a danger or cause an interruption of supply.

So where does it say in the regs you run can export the DNO earth?!

 

[bigbob1]

It is a requirement of ESQCR (Reg 24 I believe) for the DNO to provide consumers a connection point to either the network neutral or protective conductor, for connection of the installation earth.
Regulation 25 allows the DNO to refuse this connection only if the installation fails to comply with BS7671, or could pose a danger or cause an interruption of supply.

So where does it say in the regs you run can export the DNO earth?!

Does it?
Can’t say I’ve really noticed.

What’s your membership number?

 

[Richard Burns]

My take on this is that any paid work being done, no matter the location, comes under HASAWA and EAWR, this includes domestic properties.
Because the requirements are to maintain safety, this must be done during the works and can be achieved, electrically, by following BS7671.
Therefore, only if there are no changes, after the work has finished it must not present a danger; if it does present a danger then the work that was being done was not, at that time, in accordance with the law.
In that respect the HASAWA and EAWR do apply to the work once it is completed (but most defences would claim later changes had been made!). However when no one is actually working in a domestic property the HASAWA and EAWR do not apply to what is happening in the present, only to the effects that had happened in the past.

Regarding SWA I do not believe it is required to earth the armour, that is not being used as a cpc, at the supply end; it is just best practice. The shorter fault path leads to better compliance with the minimum standards of BS7671 by reducing the impedance of the fault path.
Earthing the armour at both ends, when it is not a cpc, may lead to circulating currents through the armour, but the level of disadvantage must be weighed up against the advantages of having two earthed points on an exposed conductive part.
However where the two ends are in installations with different earthing arrangements then 542.1.3 applies and the supply end only must be earthed.
The default case of the armour as a cpc clearly requires continuity and therefore earthing at both ends.

 

[Octopus]

Are you going to ignore ‘manufacturers instructions’? And are you going to let us all know what ‘SWA glands’ are produced for if not to go on SWA cable?
SWA is an extraneous conductive part......go back to college.
134.1.1

That DOES NOT answer my question, the question that has haunted this thread for pages

Please answer my question ......

 

[Wilko]

Sorry @bigbob1 but you have gone beyond my simple mind. I've read the references you've kindly provided and I can't see a problem using an already in place TNCS/PME DNO cutout to supply a shed. No going to jail that I can see, provided it's done in accord with our usual BS7671. What have I missed ?

 

[bigbob1]

That DOES NOT answer my question, the question that has haunted this thread for pages

Please answer my question ......

That is the answer......134.1.1 and you don’t understand because you have’nt got enough experience or training. There’s only 2 places I can name where you insulate SWA from connection.

Using VSD’s
And leaving equipotential zones.

 

[Dave OCD]

The question was and still is WHERE DOES IT STATE THAT THE ARMOUR MUST BE CONNECTED TO EARTH AT THE SUPPLY END

 

[bigbob1]

Sorry mate, but you have now gone beyond my simple mind. I've read the references you've kindly provided and I can't see a problem using an already in place TNCS/PME DNO cutout to supply the shed. No going to jail that I can see, provided it's done in accord with our usual BS7671. What have I missed ?

That ‘given earth’ is for ‘that equipotential zone’

You won’t understand because you can’t grasp the importance of an equipotential zone on a tncs supply. So I 100% know you will never understand. So will stop there with you.

 

[Deleted member 26818]

So where does it say in the regs you run can export the DNO earth?!

More importantly, where does it say you cannot?
Membership No. 86042686.

 

[Dave OCD]

That ‘given earth’ is for ‘that equipotential zone’

You won’t understand because you can’t grasp the importance of an equipotential zone on a tncs supply. So I 100% know you will never understand. So will stop there with you.

Arrogant and extremely disrespectful !

 

[bigbob1]

The question was and still is WHERE DOES IT STATE THAT THE ARMOUR MUST BE CONNECTED TO EARTH AT THE SUPPLY END

Because it is in the HOUSE and running through the fabric of the HOUSE and in the HOUSE equipotential zone...because it’s an extraneous conductive part.....and not with a strap but with an SWA gland 134.1.1

 

[bigbob1]

Arrogant and extremely disrespectful !

Nothing more to say to you.

 

[bigbob1]

More importantly, where does it say you cannot?
Membership No. 86042686.

Look at that you are slowly working out how a ‘guide book’ works....

 

[Deleted member 26818]

Look at that you are slowly working out how a ‘guide book’ works....

Now you’re being a dick.

 

[Deleted member 26818]

The thing about Bigbob1 and his arguments, is that they are not based in fact and he cannot back up anything he states.
If a law of physics prevents us from doing something, permission from the DNO will not suddenly allow us to do it.
GN5 (although my copy is from 2004) makes no mention of us not being allowed to export any earthing system.
Same applies to ESQCR and EAWR.
In fact, ESQCR requires the DNO to allow me to export the earthing system, the only reasons they can refuse is if the installation does not comply with BS7671, is unsafe or if it might cause a disruption in network supply.