Earth Fault, Loop Test Reading >200ohms


Postby BLAKEY1963 » Wed Jun 20, 2007 8:16 pm

[quote="The Renovator"]Scottish Power are coming out tonight. By the sounds of it they will just do what ever is necessary to get the reading to what it should be.

I asked the sparky who fitted originally the board about R.C.D . PROTECTION and he said he left it out because I have an old house and in such circumstances fitting R.C.D tends to make things trip all the time! Are you saying, however, that if I get my current problem sorted out then R.C.D protection won't be necessary?
If it is necessary then is it just an upgrade to the fuse box or does it entail upgrading every socket in the house (excuse my ignorance again).[/quote]

RENOVATOR
NOT FAR AWAY FROM SORTING THINGS OUT.
THINGS YOU CAN FIND OUT ?

ASK SCOTTY POWER WHAT TYPE OF EARTHING FACILITY
THEY HAVE PROVIDED U WITH . ( AS I HAVE MENTIONED ALREADY , IT IS
GOING TO BE ONE OF THREE, TT , T.N.S. OR TNCS. ( ASK WHAT ZE VALUE IS IF U CAN )
AS SOON AS WE KNOW WHAT METHOD OF EARTHING U HAVE, WE CAN ADVISE U FURTHER ABOUT , RCD , S , WHAT LEVEL OF PROTECTION
ECT. . IMPORTANT IS WHAT METHOD OF EARTHING U HAVE .
WAITING TO ADVISE
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Postby sparx » Thu Jun 21, 2007 8:34 am

Hi agn renovator,
I am appalled by your original electricians off hand attitude, It is mandatory to test and give the customer a (top) copy of the certificates, if he had done so then any circuits showing a low L or N to Earth insulation reading could/should have been investigated at the time. If none then an RCD could have been fitted without problem.
The above inspection/tests would have revealed your missing main earth as well, you say the house has been rewired so surely you have all new fittings already ,or did I miss something here?
RCD's get accused of 'nuisance-tripping' but they can only trip if there is an unbalance between current flowing out thro' Live conductor & current flowing back thro' Neutral, this can normally only happen due to an earth fault giving an alternative return path by-passing RCD's Neutral.
so if they trip there is a reason.
regards & good luck SPARX
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Postby The Renovator » Sun Jun 24, 2007 9:58 pm

Hi again guys, cheers for the further responses. Scottish Power acknowlege there is no earthing to the mains, however they have recently changed policy so that they no longer do anything in situations where earthing doesn't exist. It was quite confusing stuff because on teh one hand they consider my situation to be an emergency but on the other they didn't want to help. They told me to get a sparky in, I told them that I've had 2 in an dthey were scared to even go near it. Scottish Power said in teh end taht they would do it for £100 so I was left a bit bemused as to what all the fuss was about. £100 or a safe home for my family? hmm.
Anyway, they have agreed to upgrade the supply anyway, on the basis it is over 60 years old so they are going to come out "in about 3 months or so" and do that for free. Only at that stage can I ask the question about type of earthing so that I can come back to you guys for advice on RCD.

When you talk about my sparkys off hand attitude, its a scenario I'm pretty used to. Scottish Power wer ejust as bad and it seems liek a competition to see who can coem up with the best excuse not to fix my problem. Remember it wass found by Scottish Gas - they won't touch my boiler until this is fixed and the boiler (year old) has concked out 3 times since it was installed. Catch 22 or what! I've been renovating my house for teh last 2 years and every tradesman I have had has done me over one way or the other. Really appreciate speaking to a couple of guys who care though. Will keep you in the loop (pardon the pun).
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Postby BLAKEY1963 » Mon Jun 25, 2007 11:49 am

[quote="The Renovator"]Hi again guys, cheers for the further responses. Scottish Power acknowlege there is no earthing to the mains, however they have recently changed policy so that they no longer do anything in situations where earthing doesn't exist. It was quite confusing stuff because on teh one hand they consider my situation to be an emergency but on the other they didn't want to help. They told me to get a sparky in, I told them that I've had 2 in an dthey were scared to even go near it. Scottish Power said in teh end taht they would do it for £100 so I was left a bit bemused as to what all the fuss was about. £100 or a safe home for my family? hmm.
Anyway, they have agreed to upgrade the supply anyway, on the basis it is over 60 years old so they are going to come out "in about 3 months or so" and do that for free. Only at that stage can I ask the question about type of earthing so that I can come back to you guys for advice on RCD.

When you talk about my sparkys off hand attitude, its a scenario I'm pretty used to. Scottish Power wer ejust as bad and it seems liek a competition to see who can coem up with the best excuse not to fix my problem. Remember it wass found by Scottish Gas - they won't touch my boiler until this is fixed and the boiler (year old) has concked out 3 times since it was installed. Catch 22 or what! I've been renovating my house for teh last 2 years and every tradesman I have had has done me over one way or the other. Really appreciate speaking to a couple of guys who care though. Will keep you in the loop (pardon the pun).[/quote]

RENOVATOR
MOST URGENT YOU CANNOT WAIT 3 SECONDS LET
ALONE 3 MONTHS. IT IS POSSIBLE YOU HAVE NO ADEQUATE MEANS OF FAULT AND SHOCK PROTECTION . FROM WHAT YOU REPORTED WE CAN ESTABLISH A MEANS OF EARTHING AND MOVE FORWARD.
SCOTTISH POWER HAVE ACKNOWLEDGED THAT THEY R NOT PROVIDING
A METHOD OF EARTHING FOR YOUR SUPPLY AT YOUR HOUSE.
IN THESE CIRCUMSTANCES THE CONSUMER WOULD PROVIDE HIS OWN METHOD OF EARTHING , CARRIED OUT BY A REGISTERED ELECTRCIAN.
AS SPARKES HAS CORRECTLY POINTED OUT IT IS NORMAL FOR THE ELECTRICIAN TO DOCUMENT AND TEST IN THIS CASE AN ELECTRICAL
INSTALLATION CERTIFICATE TO PROVE THE SAFE OPERATION OF THE EARTHING FACILITY AFTER INSTALLING IT.
ONCE SPARKY HAS SUNK AN EARTH ELECTRODE, HE WOULD RUN OFF THIS AN 16 MM2 EARTH CABLE BACK TO THE MAIN EARTHING TERMINAL AT YOUR CONSUMER UNIT. THIS CABLE WOULD BE YOUR EARTHING CONDUCTOR . THIS IS KNOWN AS A T.T SYSTEM AND WILL BE RECORDED ON YOUR TEST CERTIFICATE.
CONTINUTIY OF EARTHING CONDUCTOR, AND EARTH LOOP IMPEADANCE
TEST EXTERNALLY ZE WILL BE TAKEN AND RECORDED ON YOUR TEST FORMS.
ONCE AN EARTH HAS BEEN VERIFIED , THEN THIS WILL DETERMINE
WHETHER DISSCONECTION TIMES FOR YOUR PROTECTIVE DEVICES
( M.C.B ) CAN BE MET SAFELY . IF YOUR EARTH LOOP IMPEADANCES
R HIGHER THAN LISTED IN BS 7671, THEN AN RCD WOULD BE NEEDED TO PROTECT ALL THE CIRCUITS ON YOUR MAINS BOARD .
TYPICAL VALUES COULD BE 100MA TRIP FOR ALL CIRCUITS EXCEPT FOR SOCKETS OUTLETS USING CLASS I EQUIPMENT ( EXPOSED METAL
WORK OF APPLIANCE ) , SOCKETS LIABLE TO USE OUTDOOR EQUIPMENT, AND INSTANTANEOUS SHOWERS IN SPEACIAL LOCATIONS ,
ALL OF THESE 3 LISTED ITEMS PROTECTED BY A 30 MA TRIP.
GRANTED U R WAITING TO SEE IF SCOTTISH POWER GIVE U AN EARTHING FACILITY ( TNCS OR TNS ). UNTILLTHEN YOU NEED AN
EARTH ROD INSTALLED , BACKED UP BY AN RCD MAINSWITCH
A.S.A . P. ALL THIS ONCE TESTED SHOULD GIVE U ADEQUATE SAFETY
AND YOUR CERTIFICATE COULD BE PRODUCED FOR SCOTTY GAS TO
COMPLETE THIER WORK .
BLAKEY1963
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Joined: Wed Jun 13, 2007 10:57 pm


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