Taking cables from a house to a garage

[ianmacd]

Normal procedure, is to connect all the exposed-conductive-parts via CPCs to the MET.Do you agree?

If the Zs are not low enough, it then suggests that the exposed-conductive-parts are connected to the MET.

What would that achieve, how would that bring the Zs low enough?

If you know that the Zs aren't low enough when the CPCs are connected to the MET, connecting them to the MET, is not going to change anything is it?

I would agree with your first statement but subject to a successful Zs test. If it hasn't passed then its not connected so your example only relevant when something is already connected not when you install it.

There are a number of ways you could lower the Zs that still involves using the MET CPC rather than an isolated, not connected to anything else rod..

 

[Andy™]

Im just about spent trying to explain 1st year basics to people,

strange... i clearly remember having to explain extraneous to you a few weeks ago, yet it waw always your way or its dangerous, even though you never backed up anything with a reg, yet i did, along with others.

 

[ianmacd]

I hope these light evenings come soon so our collective PMS dissipates.

 

[spinlondon]

542.1.5 says nothing of the sort. It says the supplied earth (or provided by rod) can be used as both a Protective Conductor and a Functional Earth.

This is a wind up right?

Section 542 lists all the types of earthing arrangements, 542.1.2 (TN-S), 542.1.3 (TN-C-S) and 542.1.4 (TT & IT).

Followed by Regulation 542.1.5:

"The earthing arrangements may be used jointly or separately for protective and functional purposes, according to the requirements of the installation."

If you use an earth as both protective and functional earth, would that be jointly or separately?

 

[ianmacd]

This is a wind up right?Section 542 lists all the types of earthing arrangements, 542.1.2 (TN-S), 542.1.3 (TN-C-S) and 542.1.4 (TT & IT).

Followed by Regulation 542.1.5:

"The earthing arrangements may be used jointly or separately for protective and functional purposes, according to the requirements of the installation."

If you use an earth as both protective and functional earth, would that be jointly or separately?

Please do not take this the wrong way but you do know the difference between functional and protective earths dont you?

 

[ADS]

12 pages and still no valid reason why you can't ha ha

As for not having two earthing systems on one installation - I, and probably a few others on here, have seen TN-S supplies (clamp on sheath), with a link to the cutout (neutral) as well - what are we calling that one then?

Or is that TN-C-S with the sheath bonded?

Is there a difference? - once again parallel paths......parallel paths are good!

 

[steptoe]

I would suggest you re-read it again.Why would it ask you to connect all the exposed-conductive-parts to the TN protective conductor or to an earth rod?

Wouldn't the CPCs have already connected the exposed-conductive-parts to the TN protective conductor?

you do NOT have access to a TN connection

that is a DNO copnnection so you cannot assume anything out of your control

Just admit it, steps, you don't like people .

not a lot sometimes,

[quote name='Andy

 

[ianmacd]

12 pages and still no valid reason why you can't ha haAs for not having two earthing systems on one installation - I, and probably a few others on here, have seen TN-S supplies (clamp on sheath), with a link to the cutout (neutral) as well - what are we calling that one then?

Or is that TN-C-S with the sheath bonded?

Is there a difference? - once again parallel paths......parallel paths are good!

I thought the DNO did that deliberately on TNCS not to supply another path to that cutout but to take it somewhere else.

 

[Andy™]

did you actually quote the law to me, or just your opinion of a recommendation?

going by your posts on here I very much doubt you even grasp the very basics of earthing systems never mind how they correlate.

I, along with SL & others, quoted 7671. you came up with nothing, except a reg which went against what you said

 

[steptoe]

12 pages and still no valid reason why you can't ha haAs for not having two earthing systems on one installation - I, and probably a few others on here, have seen TN-S supplies (clamp on sheath), with a link to the cutout (neutral) as well - what are we calling that one then?

Or is that TN-C-S with the sheath bonded?

Is there a difference? - once again parallel paths......parallel paths are good!

thats why we have a 2hr disconnection time,

your arms,torso and legs can provide the parallel path then.

its just getting more and more obvious you dont understand the difference between TNCS and PME.

your last post has 100% confirmed this.

 

[steptoe]

[quote name='Andy

 

[spinlondon]

you do NOT have access to a TN connectionthat is a DNO copnnection so you cannot assume anything out of your control

You have read the Regulation, haven't you?

It's in section 531.3 RCDs in a TN system.

The actual Reg. starts. "In a TN system."

 

[ianmacd]

I would agree that the regulation you mention there does relate to the customer side of an install but has nothing to do with supporting multiple Earthing methods.

 

[spinlondon]

I would agree that the regulation you mention there does relate to the customer side of an install but has nothing to do with supporting multiple Earthing methods.

So an installation that has both TN and TT earthing systems, would not be considered as having multiple earthing methods?

 

[ADS]

thats why we have a 2hr disconnection time,your arms,torso and legs can provide the parallel path then.

its just getting more and more obvious you dont understand the difference between TNCS and PME.

your last post has 100% confirmed this.

My last post had nothing to do with the difference between the twoheadbang

12 pages and still no valid reason why you can't ha haAs for not having two earthing systems on one installation - I, and probably a few others on here, have seen TN-S supplies (clamp on sheath), with a link to the cutout (neutral) as well - what are we calling that one then?

Or is that TN-C-S with the sheath bonded?

Is there a difference? - once again parallel paths......parallel paths are good!

 

[ianmacd]

So an installation that has both TN and TT earthing systems, would not be considered as having multiple earthing methods?

No as they are not connected as in that reg you quoted they are to be kept separate. The TT is only for the specific accessory that you can not make comply.

 

[spinlondon]

No as they are not connected as in that reg you quoted they are to be kept separate. The TT is only for the specific accessory that you can not make comply.

So you believe, although you still haven't put forwaed a valid reason for such belief.

It is still one installation, with two unconnected earthing methods.

 

[ianmacd]

I have put forward my proof, you have just decided to ignore logic.

Its one installation with one earthing method at the MET. After all isn't that how we define an earthign type for an installation?

 

[spinlondon]

I have put forward my proof, you have just decided to ignore logic.Its one installation with one earthing method at the MET. After all isn't that how we define an earthign type for an installation?

And another somewhere else.

 

[ianmacd]

And another somewhere else.

Where. There is only one connected to the MET. Where is this other you refer to? The Accessory you added a rod to maybe? Well the earthing for that accessory is not the same as the rest of the installation in the same way (omg here we go, can of worms opening) as if you don't export your TNCS to a shed and TT the shed instead.