missing earth

[jparker3007]

hi guys
i went to a customers today to do a mains change, it was a tn-s supply, the earth was to a block but there was none to the db. so while i was changing the db i rectified this with a 16mm. on doing the earth loop test with my megger it was showing voltage between L/E but wouldnt perform test. testing the socket beneath gave me an earth loop of 2.03 ohms??????

im guessing ive got a dodgy earth so what i was going to do was change it into a tn-cs arrangement, have any of you come across this before?
thanks

 

[calv68]

you should have tested the installation first mate most of the power companies dont want to no if theres an earth fault unless its a tncs system can you not just bash a spyke in or is that too much chew.

 

[jparker3007]

its actually a new install i was changing the mains first to get some safe temp power on the job(old knackered rewire db), hence i tested it first and found this problem mate

u reckon TT's best course of action?

 

[calv68]

sorry your post read like you had put the board on first. i would just spike it, in the northeast the power companies just dont want to know . i was talking to a bloke from balfours and he reckons they are on about stop supplying earths from there pme ,dont know how true that is though

 

[Spudnik]

All temporary installations MUST be spiked and not use the supplied earth.

There is a reg somewhere.

Maybe one of the others could have a look.

 

[jparker3007]

job in york so ill prob have no joy with supply authority. whats the problem with making it tn-cs?

 

[Deleted member 9648]

All temporary installations MUST be spiked and not use the supplied earth.

There is a reg somewhere.

Maybe one of the others could have a look.

Given that TN systems are permitted for fairground supplies which are about as temporary as it gets I dont think this is correct....can you elaborate?

 

[johnnyb]

All temporary installations MUST be spiked and not use the supplied earth.

There is a reg somewhere.

Maybe one of the others could have a look.

My little red books in my car , mate and me been all nice and warm in here, whats that reg if you would be so kind, so i can look tomoz.
I can,t recall where we have used our own spike for temps, we have just used the boards.
See still learning at my young age, eh! no seriously we are going to have to rectify this at our end, its important, if you can tell us ,as if this is the case we arn,t doin our job right my mate, and it must not happen.

 

[Des 56]

Temporary installations are required to be TT as stated by Jason

If the supplier were to provide a Tnc-s supply it could make the installation potentialy dangerous,because of raised neutral potential with regard to true earth
That true earth could be a service supply that is installaed in the vicinity or the structure of the building or else
The temporary must be TT

 

[Deleted member 9648]

It hasnt GOT to be a TT,if TNS is available this can be used.

 

[kung]

How about a ze of 6.2ohm ! had this few mths ago on a tnc ! some guy changed a cu with no tests or certs ! put extra socket in for them and found this so phoned m8 in SEB and within an hour had PME with nice 0.13ohm !

 

[jparker3007]

ill try that thanks mate

 

[BIGBRYERS]

Hi just a quick msg do i have to upgrade earthing arrangements if the customer only requiring extra sockets added to the existing ring and additional lights to existing circuits. I now its only minor works just am unsure

 

[rodney12]

Yes you do

 

[ezzzekiel]

unless im reading incorrectly,
you changed a board and realized the earth is missng?
and are planning on convrting the system to tncs yourself?