Minor fire when installing grounding rod into soil

[bbabythai]

We are putting in new wiring to our building and its quite a big job. I made them sign a contract. One clause was that I must be present when they install the 

grounding rod. I wanted to be sure that they did it (correctly). 

 

They banged the long copper rod into the soil and then put the round thing on top. I was standing away at this point doing something else and looked over when suddenly there was a minor fire issue- after he hooked up the wire to the white round thing on top of the rod. I was thinking jesus wept <deleted> is this and a few minutes later went to have a closer look. It was all burnt and the evidence is in the photo. 

 

The next day the boss says 'its ok'..... He said that actually it ended up being a good result bc that wire is now really connected to the rod. If anyone has experience with this can you please tell me if he is correct or should we just put another rod in close to it and get another round thing and try again??

 

Finally, is there anyway to test if its working. Please advise the method if possible. Pics attached. the photo of the A4 is what it should look like. I got it off crossy a few days ago

thanks

Edited July 30, 2020 by bbabythai

[worgeordie]

The Earth wire was actually alive, excellent electricians you employed,

the first picture shows no insulation on the cable,while the 2 other

pictures do ?

Regards Worgeordie    P.S. Then what happened ?

Edited July 30, 2020 by worgeordie

[bbabythai]

4 minutes ago, worgeordie said:

The Earth wire was actually alive, excellent electricians you employed,

the first picture shows no insulation on the cable,while the 2 other

pictures do ?

Regards Worgeordie    P.S. Then what happened ?

as stated above, the 1st pic is from the 30 page guide that crossy sent me. Its the thai manual for electric code. 

 

the 2nd and 3rd photos are of my joint.... after the mini fire/explosion. 

 

So in your opinion should I be telling them to do it again or is it ok. Only interested if you have actual knowledge of this. Waiting for crossy to reply to be honest. 

[sometimewoodworker]

59 minutes ago, bbabythai said:

So in your opinion should I be telling them to do it again or is it ok.

If that were my installation I would replace the Earth rod, the earth cable and the electriction who was incompetent enough to have the earth live. You can not trust that your wiring has actually been done correctly. You know there was an earth fault. What else is waiting to bite you or set fire to the building?

[RichCor]

I would have them demonstrate that LIVE is actually connected directly to your MAINS Breaker, and not, as I expect currently WIRED DIRECT TO GROUND.

 

If this is not a Live/Neutral reversal then there is definitely some weird unexpected current travelling to your ground rod. Maybe a bad Neutral back to the provider, causing the ground to become the return?  

[Crossy]

It's not a live earth!!

 

It's a rather poorly done thermite weld which is the approved method. 

https://en.wikipedia.org/wiki/Exothermic_welding

 

It looks a mess but in reality it's likely fine but testing it isn't easy without specialist kit. If a good tug on the wire doesn;t pull it out I'd just paint it with some acrylic paint and have done with it.

 

Do NOT bury it!

 

If you want to replace the connection you'll have to cut off the melted bit off the rod and wire, you can get earth clamps from any electical supply place. 

 

We use rather bigger ones to join rail

 

 

[thaibeachlovers]

6 hours ago, RichCor said:

I would have them demonstrate that LIVE is actually connected directly to your MAINS Breaker, and not, as I expect currently WIRED DIRECT TO GROUND.

 

If this is not a Live/Neutral reversal then there is definitely some weird unexpected current travelling to your ground rod. Maybe a bad Neutral back to the provider, causing the ground to become the return?  

If it were a current fault the insulation would have melted. I know that because the village electrician employed by the BIL wired something direct to earth and burnt out 10 meters of wire, and the plug socket, when the switch was turned on. There was no circuit breaker as it came direct from the outside mains.

[bbabythai]

4 hours ago, Crossy said:

It's not a live earth!!

 

It's a rather poorly done thermite weld which is the approved method. 

https://en.wikipedia.org/wiki/Exothermic_welding

 

It looks a mess but in reality it's likely fine but testing it isn't easy without specialist kit. If a good tug on the wire doesn;t pull it out I'd just paint it with some acrylic paint and have done with it.

 

Do NOT bury it!

 

If you want to replace the connection you'll have to cut off the melted bit off the rod and wire, you can get earth clamps from any electical supply place. 

 

We use rather bigger ones to join rail

 

 

Thanks for your reply. So it seems that what you say is in line with what my electric guy says. 

 

Do you have a pic or name of the specialist testing gadget?

 

Is it a danger to touch it. If there are kids around I worry about safety. 

 

Why do you say don't bury it?

 

many thanks

[steven100]

It's fine .... As Crossy indicated above ...  when ever there is thermite welding you will sometimes get a blob or bubble of molten slag which is nothing to worry about. You can test it to make sure there is no current with a 50 baht tester screwdriver you can buy at any Thai market.

 

You can throw a shovel full of gravel over it or place a yellow cap over it and have it level with the ground.

 

Edited July 31, 2020 by steven100

[Crossy]

6 hours ago, bbabythai said:

Do you have a pic or name of the specialist testing gadget?

Is it a danger to touch it. If there are kids around I worry about safety. 

Why do you say don't bury it?

 

 

Earth or ground resistance tester - plenty on Lazada this is just one https://www.lazada.co.th/products/uni-t-ut521-earth-resistance-tester-ut521-ohmmet-i981086876-s2122176649.html

 

No hazard if you or the kids touch.

 

You need to be able to inspect it, as noted above put some gravel over it and it will be fine.

 

[Metropolitian]

I was about to say it is not a live to ground 'explosion' but just saw Crossys reply and he is fully right.

It's exothermic welding of the wire with the rod.

Another term used is Cad Welding.

 

In this case the process was disturbed with impurities and perhaps insufficient putty closing around the 'pot'.

It's not beautiful but the connection will be there, check if the cable is sturdy welded (try to pull it) and leave it if it's strong.

 

It's not smooth; Put something (but no acidity like soil) over it so that rain/water doesn't come on it and reside in the holes to avoid the water 'eat' trough the iron but make sure it can vent.

 

I use an old paint spray can cap here on the rod, no thermic weld but copper clamp, to protect feets accidentally walking against the rod .

 

[bbabythai]

On 8/1/2020 at 3:43 AM, Metropolitian said:

I was about to say it is not a live to ground 'explosion' but just saw Crossys reply and he is fully right.

It's exothermic welding of the wire with the rod.

Another term used is Cad Welding.

 

In this case the process was disturbed with impurities and perhaps insufficient putty closing around the 'pot'.

It's not beautiful but the connection will be there, check if the cable is sturdy welded (try to pull it) and leave it if it's strong.

 

It's not smooth; Put something (but no acidity like soil) over it so that rain/water doesn't come on it and reside in the holes to avoid the water 'eat' trough the iron but make sure it can vent.

 

I use an old paint spray can cap here on the rod, no thermic weld but copper clamp, to protect feets accidentally walking against the rod .

 

thanks for your reply. 

 

if I put a old spray can cap on it can it still vent? If I put that on top and then gravel will this be ok. 

 

when you say   'no thermic weld but copper clamp, to protect feets accidentally walking against the rod .'

do you have a photo? I dont understand what do you mean by this.

 

 

[RichCor]

5 hours ago, bbabythai said:

if I put a old spray can cap on it can it still vent?

The exothermic method of using a chemical reaction to produce high heat to melt two metal joins together was a ONE TIME EVENT. The chemical is used up, leaving just the metal.

 

Other than the process sometimes leaving jagged sharp metal edges it's now perfectly safe to be around or touch.

[Led Lolly Yellow Lolly]

I'm late into this topic but as others stated the weld is much more reliable than a bolt and clamp. In Thailand the weld kids are known locally as 'one shots' (You only get one chance). Personally I'll make them do it again if it's done so badly, no matter how inconvenient. It's the prescribed method when the connection is to be buried, but I hate buried ground rods, really hate it. The out of sound out of mind attitude prevails here, but it makes inspection impossible.

 

We had lightning rods installed on one of our tall buildings, connected to 4 triangles of 3xground rods at each corner of the building. He buried the one shots welds, which hid the fact they were done so badly. I dug them up to check, made him do them all again. Of course, they'll curse the kvnt farang, but really, I couldn't care less. I have my standards.

Edited August 11, 2020 by NilSS