# earthing outside the zone



## davidmorris0107

hey, new to this site, could anybody help me with a quick question? to supply a building outside the equipotential zone using a swa cable do you need to bring your cpc from your supply board, remove that cpc and just use an installation earth electrode or use both? any help with this would be much appreciated, thanks


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## nick

*earthing outside zone*

we sometimes do both but it depends on what were looking at is this a feeder or a branch circuit , what voltage is this ? if its a feeder we use additional ground rods and tie on to counterpoise loop ground bar if its a branch we dont use anything at all .we just ground it to the ground bar in the panel .


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## frank

David

If the supply from the Supply Co meter and distribution outlet is TNS then use any three core you wish - treating the circuit to the external location as an extended radial. Via rcd and overload protection of course

If the supply is TNC (pme) you must provide all main earth/supplementary earthing/bonding as you would for a supply that was 'ready to be metered'. ie. take a 16mm with you and bond also within the terminating area of your external supply . Also rcd/overload protected.

But best of all. Just run a 2 core to the external location via an rcd and mcb within an insulated enclosure ( no glanded or other earth connection to your point of connection). At the terminal end connect an electrode with a 16mm connection.
Test the electrode with an earth loop tester if you wish but there is no need if you find that the rcd trip time is 40ms or less at 30mA.


Frank


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## nick

*earthing outside zone*

with all due respect to the uk ,frank i like to ask you what is gland , tns , three core , 2 core , tnc , meaning define for me , iam from florida usa and like to learn these terms , i guess were all electricians but i like to know what others meaning other electricians in different countries say or use different words or slogans to understand what you guys are talking about i guess ? just so ya, know i have been in your country many times and was always welcome and treated very well , like the pubs , just dont like the warm beer but iam just joking i enjoyed seein big ben and the sites , if you can explain take care best to ya from usa.


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## frank

Hi Nick

Gland. This is a brass termination fitted to the end of an armoured cable to carry the armour earth ( if used) to the metalwork of another metal component.

TNS. This is a supply authority distribution system. Systems can vary due to a variety of factors. The system type is important because the type the consumer connects to determines the earthing/bonding arrangements that are made. TN - stands for - Terra (phase) neutral/ separate throughout the system.

3 core - any cable having three cores. Each having a primary insulation and followed by ALL three coated together within a further outer sleeve of insulation.

2 Core Ditto but two cores.

TN-C A system of supply in which the neutral and earths etc are combined in one cable. David will realise though that I will be referring to a TN-C ( pme ) which is slightly different in that the neutral and earth are not a single cable but a composite of more than one cable but which in any case - any connecting neutral and earthing/bonding cable is directly connected to the same source pme section - protective multiple earthing describes the means by which the grounding is connected to neutrals.

I am sure there are web descriptions that better explain but hope this helps,


Frank


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## Trimix-leccy

addendum....

In UK Neutral and Earth are
ONLY EVER bonded together by the supply company [sometimes in the cutout which is sealed and inaccessible to all but the PoCo :whistling2:]

Internally N and E are ALWAYS seperate


...hope this makes it a bit clearer:laughing:


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## chrisb271

addendum....to the addendum........


And if you do try and link the Neutral and Earth together downstream of an RCD ( GFCI ) then you will nevr be able to use your sockets supplied from the RCD :laughing:

Chris


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## nick

thanks Frank , Trimix, and Chris, i guess i needed this to understand better Davids, question and your answer the relationship of words are not common to usa electricians ,we all do electrical work but, there is that mere matter of terminology .we appreciate your time in this matter ,to give us these definitions of each clearly . again thanks best to you in the uk.


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## Trimix-leccy

Two nations divided by a common language:laughing:


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## John

Is this cable something like what you might use in the UK?


View attachment 609


View attachment 610


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## Trimix-leccy

Absolutely nothing like any cable I have ever seen or indeed used in 34 years!:laughing:

I'll try to find some pice of what we use everyday:thumbsup:


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## John

How about this one?

View attachment 611


We may have less in common than we think.:jester:


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## Trimix-leccy

Close....but no cigar:laughing:

Trying to upload some pics to my photobucket account

Unfortunately I have forgotten my name and password

Awaiting reset


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## Trimix-leccy

whoops, wrong link sorry


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## nick

*common electric*

i only do commercial or industial mostly so this is new for me .but looking at what was said i think we call your 2 core a seu cable and your 3 core would be our ser cable in usa, but on the neutral connection we tie it in our main switch or main disconnect from power companys meter to ground rod meaning neutral grounded , in a switchboard we make a tie called a bonding jumper to the first point in the main section to ground with a bonding jumper connection any other panel or switchboard down stream from this main breaker is not made together it is neutral and ground not tied .we call any cable connector a romex connector or a cable connector . so cord connector ,which i think was what your gland is .we call the power companys meter a meter ,also the meter is grounded single phase or three phase types with a ground rod and a 4 bare solid copper to the neutral in that meter .to just the meter ,


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## John

nick said:


> i only do commercial or industial mostly so this is new for me .but looking at what was said i think we call your 2 core a seu cable and your 3 core would be our ser cable in usa, but on the neutral connection we tie it in our main switch or main disconnect from power companys meter to ground rod meaning neutral grounded , in a switchboard we make a tie called a bonding jumper to the first point in the main section to ground with a bonding jumper connection any other panel or switchboard down stream from this main breaker is not made together it is neutral and ground not tied .we call any cable connector a romex connector or a cable connector . so cord connector ,which i think was what your gland is .we call the power companys meter a meter ,also the meter is grounded single phase or three phase types with a ground rod and a 4 bare solid copper to the neutral in that meter .to just the meter ,


Here is a picture of what said ...somewhat:whistling2:

View attachment 612


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## davidmorris0107

Frank

Many thanks for your reply regarding question "earthing outside the zone". Your answer verifies my thoughts on the matter entirely and having used the 2-core+electrode method previously also puts my mind at rest! Much appreciated.

David


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## frank

Trimix. Let me help out here 'till you get back on Photobucket.












XPLC.SWA cable. Similar John to your SE but with an additional inner coating. Like Trimix I have not seen the single sheathed variety for ages,

Frank


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## frank

3 core pvc sheathed. 












3 core again but with unsheathed earth.












Frank


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## Trimix-leccy

Now that I have remembered my name and login












...steel wire armoured upto 20+ cores. Buried direct in ground or surface clipped, cable trayetc etc










... Fire Alarms etc










2 way switching or 1 feed and 2 s/wires or whatever you want really:laughing:


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## chrisb271

Trimix , you are pushing yourself too hard if you can't remember your own name :whistling2:

I have mine scrawled across the screen in big letters ! :laughing:

Chris


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## Trimix-leccy

Name across the screen......

I tried that but made the mistake of correcting the errors with Tippex...can't see a thing now:laughing:

Not been a good week...last fri we chased the suppliers ref the genny cabling[we have waited 5 weeks for them to get it done]....we then found we were doing it [they forgot to tell us, bless!] 1630 I am trying to find 185mm AWA...found it...arrived 0730 mon morning. Dug out installed and back filled by lunch on tues. Connected by tea on weds. Commissioning Eng arrives thursday; err 'we need a supply for the batt charger and heater'  and unfortunately this Transfer panel aint got the facility for that'.....it has now!!!!
All signed off, everyone happy, more dosh for us plus it makes us look good and the suppliers look like a bunch of £$%^&£$.

I wonder what monday will bring:whistling2:

Hey ho!


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## cornishsparks

Are you still using those colours in your part of the world or are we the only county to be harmonised.
RE SWA CORE COLOURS.


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## chrisb271

Don't think the guys up North have caught up yet :no:
Way behind the times :whistling2:

Everyone knows they are changing to Red , White and Blue phase colours,sure i saw something about it in my lastest copy of the wiring regulations,now where did i put the thirteenth edition :whistling2:

The bloke next door has just come up with an idea of a round thing,he says he's gonna call it the wheel ! cant see it catching on myself :laughing:

Chris


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## Trimix-leccy

Ripped the pics off the TLC website...blame them:laughing:

Anyway, tell me more of this publication that you call 'the regs'! Is it something to do with that Arkwright bloke....messing about with our Dark and Satanic Mills. They will be asking for a reduction to a hundred hour week soon and no mistake

Red to brown
yelllow to black
blue to grey 
...and blown to f%&k:thumbup:


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