Why is an exported earth bad?

[kme]

Tell me when you`re going m8.

I`ll be there. (Haven`t been up `ome in a while, now)

 

[Apache]

Be kind gents. I did what I was told by me local friendly spark.

What is the matter?

 

[steptoe]

its really not godd apache.

am off for a quick cig now so maybe someone will explain to you before i get back and start ranting!

 

[kme]

Sorry - I`m going for ciggie, too.

Then bed. I REALLY need some beauty sleep (hasn`t worked in 40 years - but i don`t stop hoping that ONE DAY..........)

Apache - If SL or the old`un don`t go over it tonight - we`ll discuss tomorrow.

Night all.

 

[SPECIAL LOCATION]

bye! ; \

 

[Apache]

I've just noticed the time. I must go sleep too. Will read the rants in the morning

Night all

 

[SPECIAL LOCATION]

I've just noticed the time. I must go sleep too. Will read the rants in the morningNight all

:z :z:z:xPray

 

[Apache]

What about me exported earth then.........

 

[kme]

OK. Have you read the posts in the thread I directed you to yesterday?

 

[a1]

No he hasn't. Apache, you naughty boy. 100 lines please...

"I will read all answer posts, when they are submitted".

:^O

 

[kme]

Well, he needs to ingest & (at least partially) understand the theory behind that thread, before we try to go on...........................

p.s. 200 lines, and a sound spanking with a wet lettuce leaf!

 

[a1]

Aww Bless 'im.

 

[Apache]

Ok - be gentle.

With a TNCS earthing system earth supplied by electricity company. My house is sat on the earth (like many others). Now I know there's no rod BUT how is this different?

Electricity under a fault passes to earth. Now I can understand how that could pass through a person in a shed to the general mass of earth but why can't it happen in my house?

The wire from the CU to my shed won't be as long as some domestic circuits. Why can't any fault current pass back along the earth wire to the MET IF it can (potentially) move from a house to a shed's earth rod?

(sorry KME missed the link yest)

 

[Apache]

I'll re-read that epic link tomorrow. I may have digested it further.

phew

 

[SPECIAL LOCATION]

Well, he needs to ingest & (at least partially) understand the theory behind that thread, before we try to go on...........................p.s. 200 lines, and a sound spanking with a wet lettuce leaf!

eh?

wet lettuce?

G-pigs like lettuce...... and cabbage... and cucumber for that matter!

any way.. DON'T WASTE THAT LETTUCE!!!

 

[Badger]

Right here goes and i await a beating

firstly TWIN AND EARTH should NEVER BE USED OUTSIDE ESPECIALLY ACROSS A SUPPORT WIRE OF ANY KIND

The suns uv rays damages the pvc and makes it go brittle, now if it was wired in conduit all the way through then its ok beasue the conduit protects the pvc froim the sun harmful rays, to do this correctly and armoured canle of 2.5mm minimum needs to be installed. But RCD only needs to be in the supply side not the shed or detached garage. I personally put all outside equipment fed from a house on its own trip and board fed from the main consumer unit through a 20 amp type b then in to a rcd unit to the garage or shed outside lighting etc etc etc

the way this should have been done is :

Out of RCD unit in house via armoured cable if possible (better to run back to cu and terminate there earth armouring dont forget.

across a catenary wire that is not earthed, then into shed cu or garage (detached) CU and from there inside the building to sockets lights etc ihn TWIN AND EARTH

hope that expalins it, The reason armoured is used is because there is more protection as there is the first pvc layer then steel armour, then a second pvc layer then the conductor pvc layer. also twin and earth will not stand up to squirells chewing the cable where as armoured will! :O

X(B-)

now what you need to do is disconnect from the supply in the house imediately, and run an armoured to that location instead.

 

[SPECIAL LOCATION]

...... I personally put all outside equipment fed from a house on its own trip...........Out of RCD unit in house via armoured cable if possible (better to run back to cu and terminate there earth armouring dont forget....

indeed so.

I also try and stick external supplies on their own MCB as well..

Also I normally put a little single gang, metal-clad, 20a double-pole isolator switch as the ideal place to terminate my SWA...

and leave a very convenient place to isolate the outside should it be needed in the future.

quite often the external is going to a garage with a freezer in it..

and if the DP switch also has a neon on it, it can give that bit of assurance to the customer that the power is still ok to the freezer.

 

[Apache]

firstly TWIN AND EARTH should NEVER BE USED OUTSIDE ESPECIALLY ACROSS A SUPPORT WIRE OF ANY KIND

.

MMM. I can think of a huge number of account of T&E been ouside unprotected. Are you saying it's against regs or just not good practice.

In my defence a proper spark designed the set up. NAPIT and everything. I've got a certificate officer. :S

 

[Apache]

indeed so.I also try and stick external supplies on their own MCB as well..

It's got it's own way in CU so on it's own MCB on the RCD side of the board

 

[Badger]

MMM. I can think of a huge number of account of T&E been ouside unprotected. Are you saying it's against regs or just not good practice.In my defence a proper spark designed the set up. NAPIT and everything. I've got a certificate occifer. :S:^O

i would class it bad practice and i think it may contravene to mechanical protection of the regs, will look in the red book after work