Grounded appliances electrocuting me

[Crossy]

WARNING.

Before you reverse anything make sure the neutral bar really is live, it could just be the colours wrong. Measure to a known earth (big screwdriver in the lawn). It should be no more than a few volts, if it's ok just live with black being neutral.

To check your rod first find it! Or at least find the lead which should be connected to it. Isolate that from the ground bar, then use a regular 15W lamp between L and the rod wire, the lamp should light if you have a reasonable ground.

WARNING II.

Keep everyone out of the house when doing this test just in case the rod isn't actually connected. It's not an ideal test, but without specialist kit you're stuffed

[Forkinhades]

Do not change the Polarity, they have used the wrong colours white is live, and black is now Neutral. If you change at the meter, you will have to change all the connections inside your fusebox. ( worth considering if your man can do it)

Once the Safety-Cut is installed, if your aircon is faulty the Safety-Cut will open.

you need to consider the MEN connection. Main Earth Neutral Connection, please refer to pinned thread.

[Crossy]

In the past I've seen aircons connected L to E, it's possible that this is what's going on and the rod just isn't man enough to pull the touch voltage down. Some serious wire tracing is going to be needed

[Forkinhades]

^ think we all concur.............posting same time lol

[tifino]

yup - just in case it really is just a Lightning Rod Earth.

agree just leave the box-wires be - if the colours area actually arse-around-tit.

As it justmeans that 2 wrongs can be made a Right...

Just do everyone a favour and get some up-to-date labelling done

Maybe sit down and watch a coupla Youtube Tesla Lightning Display videos -that'll calm the nerves down - to numb...

Edited July 1, 2014 by tifino

[bankruatsteve]

RE one circuit for the plugs: That is not the best practice. Multiple circuits are usually designed to allow for high load appliance distribution (like 2 circuits in the kitchen) and to isolate problems if/when they occur. If you are only worried about power tools, you will be hard put to overload your (20a?) breaker unless you are a welder.

[Guest StephenB]

ok, so if I did want correct polarity, - change at meter and change at fuse box so white wires (neutral) are on the neutral bar. Is that correct?

I just did another experiment as requested.

I grabed a lightning rod and some copper cable (which happens to be green)

Tested from that and took a picture to confirm Neutral (white) to ground is 220v. That means I have wrong polarity. I am guessing by replies that it is not the end of the world? lol

[Forkinhades]

White is your Live, you can see it clearly going into one side of your MCBs (fuses) and the measured voltage to earth is correct

[Guest StephenB]

Ok Forkinhades, My live is definitly the white wires then, and the consensus is just to leave it be, and just install a saftey-cut device. Also too consider a MEN.

[tifino]

if (whatever colour it is) is Live at 200v - label it, and that part of your question is resolved...

wish there was a better word to use than: 'polarity'

...keeps shoving my brain into DC world think

[Forkinhades]

^ Indeed Sir!

[Forkinhades]

With regards to MEN connection, you should be calling the PEA and asking whether or not it has been impleted in your village. They will advise whether to connect or not. DO NOT take any chances with that!!

[Guest StephenB]

No I am not sure, it is buried now under concrete from a "addition". Should I buy a long copper rod, some heavy gauge copper wire, and make another ground path just to be certain?

I was thinking that too, why did the body (me or whoever touching grounded appliances) became the shortest path and not the rod? I am thinking the ground rod has a little too much restaince.

[Forkinhades]

Leave MEN unlinked until you know for sure it has been implemented. The safety-cut device will work just as well with or without it.

Sent from my SM-G900F using Thaivisa Connect Thailand mobile app

[bankruatsteve]

And, I hope you understand that if the shocks you get are not eliminated by turning off the A/C breaker, then inserting a Safe-T-Cut front end may result in failing to set ON b/c of ground fault(s). IE: none of your circuits will have power.

[Forkinhades]

Yep install said device, turn off all MCBs, turn on one at a time, if the device opens, you are getting nearer to finding the fault.

Sent from my SM-G900F using Thaivisa Connect Thailand mobile app

[Guest StephenB]

Ok,

So now as it stands I will install the device (saftey-cut), and possibly another ground path.

This will fix the possiblilty of a family member getting electrocuted from a applaince dumping current into the ground, even with a possibly bad ground rod.

Edited July 1, 2014 by StephenB

[Crossy]

Adding a rod that you know is good will do no harm whatever

[Forkinhades]

See if it opens with existing rod. (Assuming you do have a fault)

Sent from my SM-G900F using Thaivisa Connect Thailand mobile app

[bankruatsteve]

RE ground connection: If the A/C circuit is energizing the ground wire or something connected to the ground wire, then it will carry through to ALL "grounded" appliances via the ground bar in your box. The ground rod will dissipate most of the current but not all - which is why you still get the shock. Given the voltage readings you have been getting between L and G, it seems likely that your ground rod is good as is. Add another if you want, but that will not fix the problem. You have a ground fault. That is the problem and until that is found and fixed you can add whatever but will still have the problem.

[tifino]

yeah my thoughts have been Common to the Earth line of thinking

how dry is the earth plane area?. (of course everything is drier this year)

The patch might need redoing for better conductivity

Try wetting/soaking first & see if the measurements change

[Forkinhades]

My external earth rod measures 15 ohms. Im quite close to the water table as well.

Simple ohms law tells us that with an earth fault only 15Amps will flow to earth. So no instantaneous trips will ever happen on a 20A. Even over a time period of 5 seconds a 20Amp MCB will not open!

Got it?

Sent from my SM-G900F using Thaivisa Connect Thailand mobile app

[Guest StephenB]

Just finished looking at the aircon with the issue. I ended up just removing the ground wire on the terminal that supplies power to the unit. No more problems in the house with everything on.

Something fishy is going on there though too. First on my mind, why is there a wire with the colors brown, green, and blue coming out of the drywall that supplies power to the unit? (I know it is wire codes for some countries) I tried to match up the correct colors with another wall outlet using the multimeter only to get more confused. Its almost like a ground wire is twisted in with another non ground wire maybe the live wire, behind the drywall (a guess). The house was wired for future air conditioners when built with heavy guage stuff, so the only wires inside the walls should be the quality stuff with white, green and black of the solid copper type. I did'nt use any other type of wires with those colors that are coming out of the wall. frustrated but cautiously happy

I got about a hundred things to put back together now :-)

Thanks for the help everyone, and I plan to get right on that saftey-cut device.

Edited July 1, 2014 by StephenB

[lopburi3]

Safety-Cut, I will look into that. I would have installed it or something simialr when the house was built, but I don't think I could have found it +10 years ago.

I am still concerned as why the current was not using the path to the ground rod, and instead traveling through my body (or anybody else) to earth. Does this have to do with the polarity being reversed? white/black

Actually you could have found it more than 3 decades ago - I instilled my Thailand made Safe-t-cut in 1978. Thailand was ahead of most countries with such usage (but in those days nobody had grounded outlets so even then behind on that front).