Electrical nightmares

**Derlyn** · 01-Feb-20, 08:37 PM

Hi Ians

Wait for my video.
It's in production.
Then I just need to find out how to post it onto the forum.

Cheers and peace out .... Derek.

PS. If the earth to neutral voltage is 0 Volts, which is the case in most domestic installations because the earth and neutral are connected together in either the prepaid meter or on the neutral bar in older installations, then NO current can flow between the earth and neutral..

**Justloadit** · 02-Feb-20, 07:48 AM

Originally Posted by Derlyn

Hi Ians

Wait for my video.
It's in production.
Then I just need to find out how to post it onto the forum.

Cheers and peace out .... Derek.

PS. If the earth to neutral voltage is 0 Volts, which is the case in most domestic installations because the earth and neutral are connected together in either the prepaid meter or on the neutral bar in older installations, then NO current can flow between the earth and neutral..

What about reverse fault current flow through your ELB?
That is, because you have shorted out the Neutral and the Earth through your DB, it stand to reason that there will be current flowing in the reverse direction from the utility side, through your ELB. The short will have caused a shorter path for the fault current.
You have no control of other loads on the line before your DB.
The ELB can not differentiate the differential fault current created by loads connected before or after the ELB, after all it is AC.
What I am effectively saying is that the ELB may react on effects from the supply side.

A typical example is a lightning strike down the road from your installation, in some cases this causes your ELB to trip. Now why is this, after all the lightning did not strike your installation, but yet the ELB tripped.

**ians** · 02-Feb-20, 11:43 AM

Originally Posted by Derlyn

Hi Ians

Wait for my video.
It's in production.
Then I just need to find out how to post it onto the forum.

Cheers and peace out .... Derek.

PS. If the earth to neutral voltage is 0 Volts, which is the case in most domestic installations because the earth and neutral are connected together in either the prepaid meter or on the neutral bar in older installations, then NO current can flow between the earth and neutral..

Make sure the video includes a leakage current clamp around the live and neutral and and ammeter (mA ) in series with the neutral to show there is no leakage current or current flow to earth.

**ians** · 02-Feb-20, 12:47 PM

A free tip for all the sparkies who are not familiar with a leakage current tester:

Leakage current tester are expensive (i paid about R4000 for mine many years ago)... however if you take into to consideration how much time is wasted trying to trace earth leakage faults ...this tester is worth every cent.

Where it is extremely valuable... in places where you cannot just bust out an insulation resistance tester and start pumping 500 - 1000 volts into the electrical installation due to various factors.

The easy way to trace earth leakage faults... you just clamp the tester around the live and neutral (not the earth wire) on each circuit as it enters the DB... the bonus about this method is you can actually add up all the leakage current which could also explain why you are experiencing nuisance tripping... or if you have faulty lightning protection plug tops (the red ones ) which might have taken a hit and and is not quite down to earth yet ...but causing random tripping over a period of time... this was the reason i purchased mine a couple years ago.

I got a complaint about an earth leakage unit which was tripping every 2 weeks or so... i stripped the place down...carried out insulation resistance tests on all the circuit ...they were all clear...put everything back together... 2 weeks later i got a call ...same problem... went and purchased a leakage current clamp ...figued out how to use it... went to site clamped it around the live and neutral at the DB ...found the circuit with a high reading... unplugged the computers until the value dropped ... cut the 2 plug tops off which had high reading... replaced them... problem solved.

Lucky they didnt phone Carte Blanche ...i only supplied 2 x plug tops and the bill came to about R20 000.

**Derlyn** · 02-Feb-20, 03:45 PM

Originally Posted by ians

Make sure the video includes a leakage current clamp around the live and neutral and and ammeter (mA ) in series with the neutral to show there is no leakage current or current flow to earth.

Hello my brother

All available literature, as well as my experiences over the last 41 years, suggests that an earth leakage relay will not ( and should not ) trip on a neutral/earth fault if there is no load.

To prove this with a video does not require the use of current clamps and mA meters.

It's gonna be simple, to the point, so that anyone can understand it ..... even the layman.

Cheers and peace out .... Derek

PS. You will have to forgive me but I am not a film maker or editor. I'm an electrician. So when you eventually see the video, please don't critisize my editorial or film making skills as they are non existent.

**Rifrug** · 02-Feb-20, 06:19 PM

Originally Posted by Derlyn

Hello my brother

All available literature, as well as my experiences over the last 41 years, suggests that an earth leakage relay will not ( and should not ) trip on a neutral/earth fault if there is no load.

To prove this with a video does not require the use of current clamps and mA meters.

It's gonna be simple, to the point, so that anyone can understand it ..... even the layman.

Cheers and peace out .... Derek

PS. You will have to forgive me but I am not a film maker or editor. I'm an electrician. So when you eventually see the video, please don't critisize my editorial or film making skills as they are non existent.

Hi Derek, According to me most earth leakages will trip even if circuit breaker is switched off. Have you ever installed a new circuit and the breaker is off, but you tape up the neutral wire when making the final connection because you don’t want to trip the earth leakage. Or even if you cut throug a norsk cable with breaker of it trips 99% of the time.
I would think it is because of of the distance to the Neutral/Earth bond at the transformer. The earth wire has a resistance and the neutral wire has a different resistance now put power on earth leakage and you are creating a load through the capacitance of the cable this might be mA but enough to trip the earth leakage. If the transformer is very close to the earth leakage or there is a neutral/earth bond close-by the capacitance of the wire might not be enough to trip the E.L.

**Derlyn** · 02-Feb-20, 06:45 PM

Originally Posted by Rifrug

Hi Derek, According to me most earth leakages will trip even if circuit breaker is switched off. Have you ever installed a new circuit and the breaker is off, but you tape up the neutral wire when making the final connection because you don’t want to trip the earth leakage. Or even if you cut throug a norsk cable with breaker of it trips 99% of the time.
I would think it is because of of the distance to the Neutral/Earth bond at the transformer. The earth wire has a resistance and the neutral wire has a different resistance now put power on earth leakage and you are creating a load through the capacitance of the cable this might be mA but enough to trip the earth leakage. If the transformer is very close to the earth leakage or there is a neutral/earth bond close-by the capacitance of the wire might not be enough to trip the E.L.

Hello brother.

The reason it trips is because there are other circuits supplied by the earth leakage that are on and the earth leakage is under load.

Turn off ALL the breakers to circuits supplied by the earth leakage relay then you can cut through the cable and the earth leakage will not trip.

A good tip when installing a new circuit is to do all your final connections first and connect the supply and neutral last. That way there's no chance of accidently tripping the earth leakage.

Believe me. Been there, done that.

An interesting watch https://www.youtube.com/watch?v=JTkuoMplER8

Cheers and peace out ... Derek

**ians** · 03-Feb-20, 06:52 AM

Derek all i am gona say... until i see a leakage current clamp on a circuit ...i am gona rather just stick to what i know and test carried out using the correct test equipment... it sounds like the fella who issued the COC in December last year ...he spent a whole week fixing faults so the COC should be valid... i am saying to him without the correct test results the COC is invalid... when he has to send his teams back to a site to install earth wires from the DB to the junction boxes.. that is a clear indication that his theory that a weeks worth of repairs doesnt make the COC valid...but rather the test results...so lets see the test results and then i will be convinced....until then i stick to my test results.

This explains why Carte Blanche took the fella to task...electricians in Durban are dime a dozen for a s little as R140...The electrical industrial council... the ECA and the DOL are gona have to review their minimum rates.

I wonder if the vibrators are connected to power or battery operated

ZAR140
Registered electrician offering all electrical services industrial, commercial around Durban, & supply electrical equipment [Motors and Vibrators]

https://www.facebook.com/marketplace...1290908883835/

**Dave A** · 03-Feb-20, 03:52 PM

Originally Posted by Derlyn

PS. If the earth to neutral voltage is 0 Volts, which is the case in most domestic installations because the earth and neutral are connected together in either the prepaid meter or on the neutral bar in older installations, then NO current can flow between the earth and neutral..

There's the difference right there.

Supplies in Durban are TN-S. I gather from your statement that your supplies in East London are TN-C and the installation is set up as TN-C-S.

Agreed - The first requirement for a neutral-earth fault to trip the earth leakage is a voltage difference between earth and neutral. Without it there's nothing to drive the current.

I went over our last 10 COC's issued. The lowest E-N voltage reading was 0.14 volts. With a typical loop impedance test result of 0.6 ohms, we can expect this to produce a dead short current between earth and neutral of around 233 mAmps. Perhaps more as the transformer's resistance is not going to be a factor.

For the record, the E-N range in that sample of 10 COC's was 0.14 to 0.67 volts with the 0.14 volt instance used above being the only one below 0.3 volts.

**Dave A** · 11-Feb-20, 03:46 PM

Originally Posted by AndyD

On the flip side who the hell are the ECA to dictate contractors mark-up? That pisses me off almost as much as the cowboy ripping people off using scare tactics.

As indicated previously, I share your sentiment and have followed up on this.

Attached to this post please find the official ECA SA response.

Carte Blanche 19 Jan 2020 ECASA response.pdf