Tt systems over 200 ohms

[vitoboy]

HI PEEPS
My nic inspection comming up and i have one job(new shower circuit)for them to inspect.
problem TT system and ze 298 ohms(tested with megger 1552 earth loop)
will i need to show the altenative method of showing earth stake resistance?
ie other stakes in the ground and testing between?
hoping not..........

 

[Des 56]

If you use the alternative method your reading will be a truer figure and probably lower
I would think he will not ask you for the alternative method

If he is presented with that reading on your assessment he may well ask you to justify not accepting the guidance given by the Niceic
You say 200ohms,but the Niceic I believe, make their own rules for their members and 100 ohms is their recomendation

Have you read the thread another earth rod or export from met ?
In that thread you will find how walec brought his reading down
I would take a leaf out of his book and try and do simillar in your situation

Better to explain how you overcome a bad reading than explain why you have one

 

[walec]

As Des 56 says, read the thread, I don`t know much about NICEIC but I will help best I can, I personally would bang another earth rod in and reduce the resistance, it worked for me. I tested only at the CU end, for me it was the final reading that was most important. i.e. meets the Ze/Zs requirements of 7671.

 

[Jason Smith]

um, er, have you soaked the ground near the earth rod with a bucket of water ? tested its not worked a bit loose in the ground ? Please dont accept this as an answer but I remember from my training that two o r three rods linked will eventually get you your reading- this appaarently overcomes the problem of sandy soils etc, once remember doing one with my oldsweat and a simple cleaning up the terminals (sandpaper/wetand dry ) improved the contacts and readings no end. Sorry key board needs replacing as it cant spell.

 

[vitoboy]

alternative method makes problems as earth rod is in a patio next to the house and surrounded by other houses.
both my jobs to be assesed are in my local vilage which has a lot of tt systems a both mine have.
its a old mining village and lots of places built on made up ground and spoil.
so the resistance of earth stake is also 300 ish ohms on my other job.
i know of places localy that have multipe stakes and still have a earth loop over 300 ohms.
i know this is a sod for first inspections but im gonna work all over these places so i need to know!
will check the other post though.
ta

 

[acat]

Above post NICEIC and 100 ohms max is correct so thats the max you are aiming for.


Good luck


Chris

 

[MarcT]

In addition to the above, consider the different types of earth electrode (you may get a better Ra off a plate than a rod) and brush up on 411.5 in case you get any left field questions.

 

[vitoboy]

bellow 100 ohms..........not a hope in hell
not without major works for my customer....who only wants a shower circuit!

some one here must be able to help.........????
or else the customer cant have any install work done by nic eic with out large scale works
this will be the case for about 30 50 properties in the area.

 

[donm]

how about the thicker rods that you screw another on top so it goes deeper have to watch out for services though

 

[Spudnik]

You will get a better reading by installing another rod, at least one rods length apart from the other and looping them together.

As long as you can get your reading below 200ohms then it should be fine.

 

[mechelec]

Can you not apply for a PME

 

[vitoboy]

ok
good a plan as any.will install another rod and see what and if any differnce in ohms it makes.
atleast ill be able to show ive tryed some things to rectify the problem.
should the supplyer no about this problem and be required to fit pme to the area.?
or am i having a laugh....ha.ha.

as ive payed for my inspection and completed my application does that mean i can use the nic help line..?

 

[Spudnik]

ok
good a plan as any.will install another rod and see what and if any differnce in ohms it makes.
atleast ill be able to show ive tryed some things to rectify the problem.
should the supplyer no about this problem and be required to fit pme to the area.?
or am i having a laugh....ha.ha.

as ive payed for my inspection and completed my application does that mean i can use the nic help line..?

The DNO are only responsible for any earthing that they supply.

If its TT then its down to you OR you could as said, phone the DNO and book a PME enquiry.

Not sure about the helpline. Probably not as you are not considered a full member until you pass your assessment and you have your membership number.

 

[vitoboy]

have phoned them and booked a pme check for said jobs.two working days to find out the result.
i was thinking they were under ground supplys but on closer inspection they are over head/under ground supplys..so could be tt only..

 

[Spudnik]

You could still have a PME from overheads.