Earth Fault Loop High ?

[acestu]

Hi, I have just purchased the martindale socket tester EZ150 which gives me an earth fault loop reading, now i plugged it into the sockets in my mates stables and the green light in the middle came on instead of the first green light, would i be right in thinking that if i have a 32 amp breaker feeding the sockets then the EFLI should not be above 1.44 ohms if so the middle green light 1.7 - 5 ohms is high, do i need to investigate this.

The stables are fed from a three core armoured and the house is about 200 feet away, i have been taught that you should not export the earthing system, so should i devorce the earth at the stable end and put an earth rod in ?

cheers
Acestu

 

[ian.settle1]

Hi, I have just purchased the martindale socket tester EZ150 which gives me an earth fault loop reading, now i plugged it into the sockets in my mates stables and the green light in the middle came on instead of the first green light, would i be right in thinking that if i have a 32 amp breaker feeding the sockets then the EFLI should not be above 1.44 ohms if so the middle green light 1.7 - 5 ohms is high, do i need to investigate this.

The stables are fed from a three core armoured and the house is about 200 feet away, i have been taught that you should not export the earthing system, so should i devorce the earth at the stable end and put an earth rod in ?

cheers
Acestu

Get a proper EFLI tester and not a mickey mouse lights gadget.

 

[gpz900jim]

it may be worth getting it investigated with a calibrated tester. I think that the tester you have is really just a rough indicator. but if i were you i would def get it looked at. You are looking for advice, which is what this site is for. I dont know why the person who answered above me has to answer in such a rude way, there is no need for it. If people cant be civilised, why contribute ?

 

[acestu]

I will be getting an all in 1 shortly as i have just past my exams...

Not really what i wanted to hear though, hope there are more helpful people on here

I love forums there always somebody like you

Acestu

 

[MNR]

hardly rude...blunt maybe...but spot on...it's a mickey mouse gadget.

+1

Sometimes bluntness is needed.

Check it out with proper tester, and let us know how you got on.

 

[acestu]

Thanks guys im not stupid i should of said that it was just a rough test which is now leading me to investigate further with proper equipment, the socket tester is a great 10 second test which can alert you to further investigation, what i really wanted was input on the rest of the question, i know you all think im just another punter fekin about with electric when he shouldnt be, but im a time served spark and i have just done 17th edition and 2391 also pat testing and pat testing management so is there any chance of a bit of friendly advice or not

thanks
Acestu

 

[hasel5]

If you have taken these course then you should be using the proper test equipment and not relying on a mickey mouse bit of kit

 

[johnboy6083]

no one is trying to imply anything mate. we have to assume that you have no knowledge, so that we dont mislead people. If somebody who isnt trained reads this, and we advocated the use of your EFLI indication device, then they might think that they could substitute a full test with that. this forum really is helpful to experienced blokes and to trainees alike. nobody knows everything.

Hope you enjoy this site

John

 

[acestu]

I am having real problems getting through to people on here , i will be using proper kit to test now that i have been alerted to the problem, it wasnt an inspection and test or anything until my friend pluged in my tester in the socket, i just wanted peoples advice on the earthing system

Acestu

 

[Deleted member 26818]

How is the earth exported?
Is it by the armour of the SWA, or through a core of the cable?
If you do divorce the earth at the stable and install a rod, unless you can get the impedance of the rod down low enough you will have to install an RCD to comply with disconnection times.
Some would consider that installing an RCD will allow you to get away with high Zs, without making the stable TT, I believe up to 1667 if using a 30mA RCD.

 

[johnboy6083]

have you checked the cable calcs? if the house is a long way away, then cable may be undersized, giving rise to high Zs. You could reduce the size of the MCB protecting the circuit, and that will allow you some flexibilty, providing all calcs hold up.

 

[nickblake]

you are correct in saying that the Max zs should be 1.44 however the maximum tested value should be 80% of that which is about 1.15 so anything higher than that should be investigated

 

[Deleted member 26818]

I guess it depends how you define an agricultural building.
In Cambridgshire the Local Authority do not consider stables to be agricultural, and they require planning permission and if sited on agricultural land a change of use application.

 

[acestu]

Finally a bit of a debate on special locations and earthing arrangments,

I was taught that different electrical supply companies have different rules on exporting the incoming earthing system, and that rule of thumb is that if the outbuilding cannot be touched from the main building then an earth rod should be used and a TT system used, what are your thoughts on this....

Interesting bit on stables as agracultural buildings...

Thanks
Acestu

 

[Deleted member 26818]

There's nothing in BS7671 preventing the exportation of an earth.
The main problem is the DNOs. Where the supply is PME, you should ask their permission before exporting.
Also if there are any extraneous-conductive-parts that require bonding, you will have to supply an appropriatly sized conductor. The armour of the SWA will not be sufficient.

 

[acestu]

Thats more like it thanks spinlondon for your greatly appreciated input

cheers
Acestu

 

[nickblake]

Special locations ,stables are Part of agricultural buildings and special locations section 705 of the regs ,and the reason is horses can be classed as live stock its an animal so it is required to be protected against electric shock and burns etc also stables contain flammable and combustable materials IE straw and hay , also the cleaning methods in stables are water jets so it will then require accessories to be IP rated to IPX5 , cabling should be protected against damage which in general terms will be SWA as steel conduit rusts , as for a question the swa although you can use the armour as an earth, but it would be far more benificial to use a cable with an incorperated earth as some sizes you will require an additional earth

 

[acestu]

Top Answer Nick Blake thanks for your input & Merry Christmas

cheers
Acestu

 

[Amp David]

Damn, i've asked for one of those tester sockets for christmas, i'll have to send it back in the new year if they're no good

 

[acestu]

They are NOT Tester Sockets Amp David they are Socket Testers, maybe they are no good for Dyslexic sparks

Merry Xmas
Acestu