earth bonding

[44ALLAN]

You were right with the 22kΩ Tel-there's another 1000Ω allowed in the equation for the resistance of a human body

What happens if your voltage is 246 tho !
Be more than 10mA using them numbers

 

[telectrix]

You were right with the 22kΩ Tel-there's another 1000Ω allowed in the equation for the resistance of a human body

i forgot about the 1K. must have been thinking of that andre preview. he's a better conductor.

 

[snowhead]

What happens if your voltage is 246 tho !
Be more than 10mA using them numbers

10.69ma

 

[44ALLAN]

10.69ma

Well that's all right then...........................................what's .69 of a milliamp anyway:wink_smile:

 

[Engineer54]

TNCS, this system provides a split concentric cable (it looks like a single core SWA cable if you cut through it..dont!) to the supply head, The core is used as the Line, the steel armouring is connected to the Neutral at the supply head, and the main earthing conductor goes into and connects to the Neutral in the supply head from either an adjacent earth block or the earth bar in the CU. Therefore there is only one combined connection for the Earth and Neutral from the supply head to the supply transformer. In some cases the distributor will fit additional earth rods to the split concentric cable to ensure that the Ze stays in spec. TNCS is sometimes referred to as "PME" protected multiple earthing

.

Nope on a TNC-S it'll be a ''Concentric'' cable, a ''Split Concentric'' is a TN-S cable. Split meaning, the surrounding outer conductors are split between insulated neutral conductors and bare earth conductors. Split concentric cable is used by the DNO to replace old and/or damaged TN-S PILC cable, be they waveline armoured or otherwise...

There is no steel armouring in either the concentric or split concentric cables. The surrounding uninsulated neutral conductors on a TNC-S concentric cable are copper.

 

[N6rul]

exams

Ill become a star in my class with this kind of info. Great work guys.

 

[brucelee]

I Knew others such as howard or engineer would be able to explain better lol

 

[Engineer54]

Finally found some photo's where these cable types have been used!! To add insult to injury, from a DIY site!! lol!!


DIY and Home Improvement Wiki - Electrics - Cable types - Concentric type cables straight concentric and split concentric

 

[Toonlad]

Just looked at the split concentric photo link not keen on using a red conductor on the neutral.

 

[Engineer54]

Just looked at the split concentric photo link not keen on using a red conductor on the neutral.

That's meter fitters for you!! lol!! Probably only had red tails in the van, or as is not too uncommon these days got his polarity wrong!! lol

 

[brucelee]

Yep nice identification of conductors there and He didnt seem to interested in making it look neat either or bother about the bare copper on the earth rough as
But thanks for posting the pics as I had seen the cable but never used any or seen it used not had the need to look inside a cut out before lol apart from when the fuse falls out

 

[Engineer54]

Actually a couple of the photo's show quite well made off cables, Shame about the lack of sleeving in one of them (the 1st photo is the normal DNO not too bothered standard mess), the last photo into a CU is very neat work. Whoever did this, took his time to make it look well done. Most of the concentric terminations i've seen, look a real amateurish mess!! On the few occasions i've made these cable off (split concentric), i have used a heat shrink 3 core breakout and coloured heat shrink tubing. It always gives the termination a far more professional finish!! lol!!

 

[Toonlad]

That's meter fitters for you!! lol!! Probably only had red tails in the van, or as is not too uncommon these days got his polarity wrong!! lol

I see it quite often too. More so on the meter side, never see much in the cutout side. I just put a ring of tape on to identify it, i just cant help myself. Probably ocd LOL

As you have linked the pics, some can visualise behind the cutout now, and gives them a better understanding, how we get the characteristic of supply. +1

 

[GLENNSPARK]

And earthing and bonding are two different things

yeah...i keep tryin to drive this message home in here Allan...

 

[iamelectric]

telectrix i tested between MET and pipe using megger 1552 on 500v comes up >299M not got kohm setting , any ideas