Electric Shocks From Household Appliances

[Bomonster]

Hi need some help on this one. Have just moved into new house and my wife got a big shock off the dishwasher. The appliance is new and a stainless steel finish. I fitted a 3rd earth pin as a solution told me by the seller, this eliminated the shock issue, but having read on the net that the problem has been only bypassed and not cured, ie loose wire problem is stiil there but is now going to earth.

I then got the sellers electrician who immediately went to open the wall socket not even looking at the appliance. The builders electrician says the electric is fine. The appliance seller actually got a live from the microwave, but we have no shocks from that.Trying other sockets for the dishwasher 2 pin only it is live on everyone. I am confused by the second appliance being live, being sure it was a fault in the dishwasher. anybody can solve my puzzle please, ps no lives from any of the showers or any other electrical device(apart from micro again fit a third pin gone) and we have many. thanks

[Crossy]

It's not unusual for domestic appliances to leak enough to give you a tickle when they are not correctly grounded. Things involving water (washing machine, dishwasher etc.) are, for obvious reasons, particularly prone. These machines are intended to have a ground wire and should not be operated without one although you may see a difference if you put the plug in the other way round (not a recommended fix by the way).

Provided it doesn't take out your GFI/ELCB/RCCB/RCD/Saf-T-Cut trip (you do have one don't you?) when the ground is connected there probably isn't a dangerous fault just a slight leakage. Your PC probably leaks enough to give you a strong tingle when run without the ground although that's caused by the mains inlet filter rather than water.

A loose wire internally will definately drop the breaker when the ground is connected, this type of fault could be lethal if no ground is provided

Edited February 12, 2008 by Crossy

[lopburi3]

Put a ground pin plug on the microwave also - they should always be grounded. Refrigerator, washing machine, water cooler are several other items that should always have grounded plugs.

[Crossy]

Put a ground pin plug on the microwave also - they should always be grounded. Refrigerator, washing machine, water cooler are several other items that should always have grounded plugs.

Absolutely!!! Anything that has a 3 pin plug (including the round Schuko or Euro plug that for some reason gets put on these appliances here) will need a ground.

Also have a look here http://www.crossy.co.uk/wiring/

[Bomonster]

It's not unusual for domestic appliances to leak enough to give you a tickle when they are not correctly grounded. Things involving water (washing machine, dishwasher etc.) are, for obvious reasons, particularly prone. These machines are intended to have a ground wire and should not be operated without one although you may see a difference if you put the plug in the other way round (not a recommended fix by the way).

Provided it doesn't take out your GFI/ELCB/RCCB/RCD/Saf-T-Cut trip (you do have one don't you?) when the ground is connected there probably isn't a dangerous fault just a slight leakage. Your PC probably leaks enough to give you a strong tingle when run without the ground although that's caused by the mains inlet filter rather than water.

A loose wire internally will definately drop the breaker when the ground is connected, this type of fault could be lethal if no ground is provided

cheers i have a consumer box with trips they dont trip out, had a meter on the dishwasher and microwave no earth 100v and 75v non of the devices were running just switched on?

[Crossy]

cheers i have a consumer box with trips they dont trip out, had a meter on the dishwasher and microwave no earth 100v and 75v non of the devices were running just switched on?

Yeah, with voltages of this magnitude read on a DMM I'd say there was no fault as such. Grounding will fix the tickle with no safety issues

If your meter does AC current measure the earth current, if it's less than, say, 5mA, there's no problem.

Edited February 12, 2008 by Crossy

[Phil Conners]

Actually in Europe I've had most appliances, including washing machines, refrigerators and microwaves - and of course PC's, run on 220 VAC without ground and I've never had as much as a tickle from it. Here practically everything that isn't grounded zaps me. There must be something different with the power in Thailand; maybe different phase or something? The humidity?

Edited February 12, 2008 by Phil Conners

[Crossy]

Actually in Europe I've had most appliances, including washing machines, refrigerators and microwaves - and of course PC's, run on 220 VAC without ground and I've never had as much as a tickle from it. Here practically everything that isn't grounded zaps me. There must be something different with the power in Thailand; maybe different phase or something? The humidity?

In some European countries the household supply is actually phase-phase (delta) rather than phase-neutral (star) as in Thailand (and the UK), in this case any leakage to about half rail will hover about ground, hence no bite

Trouble is that you need double-pole MCBs on your outlet spurs

Edited February 12, 2008 by Crossy

[Bomonster]

cheers i have a consumer box with trips they dont trip out, had a meter on the dishwasher and microwave no earth 100v and 75v non of the devices were running just switched on?

Yeah, with voltages of this magnitude read on a DMM I'd say there was no fault as such. Grounding will fix the tickle with no safety issues

If your meter does AC current measure the earth current, if it's less than, say, 5mA, there's no problem.

thanks again lads

[Swedexku]

cheers i have a consumer box with trips they dont trip out, had a meter on the dishwasher and microwave no earth 100v and 75v non of the devices were running just switched on?

Yeah, with voltages of this magnitude read on a DMM I'd say there was no fault as such. Grounding will fix the tickle with no safety issues

If your meter does AC current measure the earth current, if it's less than, say, 5mA, there's no problem.

thanks again lads

[Swedexku]

I recognize all of these problems in my case the third ground pin did not help still a leakage to the washing machine chassis and microwave. I noticed that it was worse in the evening between 19.00-20.30 (when people using the electrical showers.). I bought a good voltage meter and was checking the voltage. Found that this time in the evening the voltage was as low as sometimes 150 volt. During the day I hardly reached more than 170 volt.

Did have problem with TV keep on shutting off, fluorescent lamp hard to light etc.

However a nasty letter to the electrical company and a complete new wiring to this area solved the problem also to a few of my neighbours. I could see when the voltage reach 190 volt and over the leake to earth is reduced as much that I no longer get any chock from the machines. You should have at least 200 volt to be sure preferably 220-230 Volt.

[andyadam]

Hi need some help on this one. Have just moved into new house and my wife got a big shock off the dishwasher. The appliance is new and a stainless steel finish. I fitted a 3rd earth pin as a solution told me by the seller, this eliminated the shock issue, but having read on the net that the problem has been only bypassed and not cured, ie loose wire problem is stiil there but is now going to earth.

I then got the sellers electrician who immediately went to open the wall socket not even looking at the appliance. The builders electrician says the electric is fine. The appliance seller actually got a live from the microwave, but we have no shocks from that.Trying other sockets for the dishwasher 2 pin only it is live on everyone. I am confused by the second appliance being live, being sure it was a fault in the dishwasher. anybody can solve my puzzle please, ps no lives from any of the showers or any other electrical device(apart from micro again fit a third pin gone) and we have many. thanks

I had this a while back, the "sparks" from the electric company had reversed the polarity on the house!!!! It could be the pos connected to the neutral at the meter!!!!

[stgrhe]

I suggest all appliances that are used in kitchen and bathrooms be grounded as a defect else could be fatal. It is also important to ensure that the phase and the neutral and the neutral and the grounding have not been swapped.

If you have a multi-meter measure select ohm measurement on your meter and measure the appliance you have problem with. The power plug should be out. Measure all three pins including the grounding pin to the the chassis of the appliance. Only the grounding pin should read 0 ohm while the other two should read well over 10M ohm. This ensures that neither the phase nor the neutral have mistakenly been swapped with the ground. If they have, you are in jeopardy and could end up dead.

[lopburi3]

Actually swapped wires are common in Thailand and plugs are not polarity keyed (they fit both ways). Very few bathroom appliances are equipped with ground plugs (almost all are doubled insulated) so believe an RCB upstream is much more important than grounded outlets in that case. Surly anything that is designed to be grounded should be (water heater as important example).

Agree with the plug test to confirm ground but without being sure the wall socket is grounded it is false security. Have electrician test wall socket to be sure the hot to ground shows the same voltage as hot to neutral. Unless you are used to using multimeter on live circuits it is probably best not to do yourself as holding two probes and reading meter can be a task.

[morris78]

This grounding or earthing problem is extremely common in Thailand. Extremely common. I've seen too many computers damaged, such as when you plug in a printer or monitor or phone line and poof, it's dead. Shocks from electric showers, stoves, washing machines, even air conditioners.

People have been electrocuted here

Don't rely on Thai electricians. They will say things are grounded "SURE!" when they just connect a wire to a screw in the cement wall, or connect to a beam in the ceiling or something like that. That's WRONG. This Is Thailand ...

If you have a ground but aren't sure how good it is, then measure it. Check it with a voltmeter and if you don't get 220 volts in measuring hot to ground, then the ground is poor. Compare it to hot to neutral.

You should get a grounding rod from a hardware store. They are common, usually for 100 baht or less. Copper or maybe lead coated. 2 meters long. In Bangkok, the soil is soft and wet so you can push it down with your hands. After it's halfway down, get a board and sit on it (but be careful lest you slip or it break and you get injured in your butt or worse), and it will go down all the way in a few minutes. Outside Bangkok, it's rocky in some places. Put it in a place with wet soil such as where your air conditioner drips and drive it down as far as you can. If you see a metal pipe going into the ground with no PVC, that might work as a ground, but most piping is PVC in Thailand now.

Connect the ground wire to that grounding rod. Or connect multiple ground wires. Or twist together ground wires very well and run one back to that rod. Make sure the connection to the rod is strong without stripping the screw.

Run the ground wires to the chassis or to the 3rd prong adapters. Check all power strips because many have a 3 prong plug but it's not connected. Check polarity of strip and everything after connection because it's often reversed by wiring inside. Air conditioners need only the outside compressor grounded since it's connected to the inside by copper tubing.

Proper polarity on a power plug is this: If the ground is at the bottom, then neutral is top left and hot is top right.

Hope this is clear enough.

Google grounding earthing and you will get the best instructions, some of it simple and easy enough.

[Bomonster]

thanks alot again lads most helpful

This grounding or earthing problem is extremely common in Thailand. Extremely common. I've seen too many computers damaged, such as when you plug in a printer or monitor or phone line and poof, it's dead. Shocks from electric showers, stoves, washing machines, even air conditioners.

People have been electrocuted here

Don't rely on Thai electricians. They will say things are grounded "SURE!" when they just connect a wire to a screw in the cement wall, or connect to a beam in the ceiling or something like that. That's WRONG. This Is Thailand ...

If you have a ground but aren't sure how good it is, then measure it. Check it with a voltmeter and if you don't get 220 volts in measuring hot to ground, then the ground is poor. Compare it to hot to neutral.

You should get a grounding rod from a hardware store. They are common, usually for 100 baht or less. Copper or maybe lead coated. 2 meters long. In Bangkok, the soil is soft and wet so you can push it down with your hands. After it's halfway down, get a board and sit on it (but be careful lest you slip or it break and you get injured in your butt or worse), and it will go down all the way in a few minutes. Outside Bangkok, it's rocky in some places. Put it in a place with wet soil such as where your air conditioner drips and drive it down as far as you can. If you see a metal pipe going into the ground with no PVC, that might work as a ground, but most piping is PVC in Thailand now.

Connect the ground wire to that grounding rod. Or connect multiple ground wires. Or twist together ground wires very well and run one back to that rod. Make sure the connection to the rod is strong without stripping the screw.

Run the ground wires to the chassis or to the 3rd prong adapters. Check all power strips because many have a 3 prong plug but it's not connected. Check polarity of strip and everything after connection because it's often reversed by wiring inside. Air conditioners need only the outside compressor grounded since it's connected to the inside by copper tubing.

Proper polarity on a power plug is this: If the ground is at the bottom, then neutral is top left and hot is top right.

Hope this is clear enough.

Google grounding earthing and you will get the best instructions, some of it simple and easy enough.