Minor Electric Shock - Washing Machine

Does this current / shock is due to static electricity of washing cloth?

Not likely Since after the amount of drying the washing machines do won't be able to make the clothes dry enough not to conduct electricity and thereby self discharge. Afterall you don't remove the clothes seconds after the cycle is completed. I don't know samsung but my IFB opens the lock after a minute or so.

The pipeline is metallic? Mine is a plastic.

Anyway there would be sealant at the joint thread which would be insulating though the water inside should be conductive.

You are likely to have a leakage problem. Better to call the service persons, may be the heating coil insulation is corroded and leaking or somewhere else the elakage is getting propped up.

BTW- I have a habit of switching off the supply before I touch any electrical appliance and in that case no shock is expected except of course through the neutral conductor if it is floating neutral and had developed voltage due to improper earthing. Since the useual 3 pin plugs would cut off the supply line not the neutral unless it is MCB

Finding a minor fault in an appliance is tough. Hook up a meter or a light to show when the fault is happening. Then carefully change things like opening the door, rotating the timer, and such. You will probably have to have a technician go through the machine to check internal parts for shorts. Finger poking in an appliance while it is plugged in is asking for trouble.

Are the plugs polarized? If not, the hot and common leads may be reversed allowing a leakage to chassis.

You have two things to do:

1. Call an electrician to at least confirm the problem if not fix it if it is an installation problem.

2. If the problem is not with your electrical system or its installation, call the appliance manufacture ASAP. The electrician's visit will prove where the fault lies and if it is the appliance the manufacture will take this problem very seriously since they do not like law suits at all.

This shock could get worse or even lethal if not fixed. Don't mess around.

Lastly, static electricity gives you a one-time poke, like reaching for a doorknob. If you continue to get shocked each time you touch it or while holding it, then you have a current leakage problem, which could get serious or deadly. I would use a voltmeter and not my finger to confirm that. However, it is best to call a pro as I stated in step #1.

You could measure for voltage between the cold water pipe and a bare screw or a ground point on the machine to see if there is a (high) voltage. *Do not touch with your hands!
To see if it's just static like you think, you could unplug the washer before handling the clothes to see if you still get shocked. This might not tell you everything if you have a seperate ground attached though.

This could be VERY DANGEROUS advice if there is aREAL electrical fault on the machine. A short from phase to earth for rxample.

Switch off, remove the mains plud and attach a device called a "Megger", which is basically a special Ohmmeter that uses a very high voltage for testing, 500 to 1000 volts AC and or DC, some achieve 5 KVolts. The voltage is often generated using a hand driven alternator (at least in my day!).

This means that any "short" to ground from damaged insulation, will still be "bridged" with the higher voltage, whereas using the standard 9 volt multimeter may not "see" the problem.

Usually a minimum insualtion of 1 MrgOhm is considered safe......but still may give the user small shocks if the connection to the house earth is missing or high resistance.

Never put such a device (washing machine) on a 2 wire system is my motto, but if you have to you must know exactly "which way round" that it must be connected......

Using a "megger" on a modern appliances with all the electronics that's inside them is definitely not recommended as it's likely to fry all the electronics regardless of whether it's turned off or on. You could open up the machine and disconnect the electronics but this would more than likely disconnect the fault as well.

The best solution would be to check the voltage between the machines chassis and ground using a digital multi metre set to measure AC volts with the machine both turned off and on. If you get more than a few AC volts with the machine turned on then there would more than likely be some sort of leakage in the machine that's giving you the shock. You could try measuring how much current the fault is capable of producing with the meter set to AC amps but with the low impedance of the metre the current may be quiet high.

Regardless of that, if you detect more than a few AC volts on the machines chassis then unplug the machine immediately, put a bloody great big DO NOT OPERATE sign on it and call the manufacturer or dealer to get an authorized service agent out to fix the problem.

By the way the correct name for a "magga" or "megger" is a magohmmeter which is a device that uses high voltages to measure high value resistances like those that you would see in the insulation on electrical wires etcetera. The high voltages that they use range from about 500 to 10 thousand volts or even more. That's why it's not a good idea to connect them to modern appliances that often use complex electronics and solid state switches to turn the power on and off. While these components can cope with norm mains type voltages hitting them with thousands of volts is likely to fry the electronics regardless of whether the appliance it's turned off or on.

Have you ever heard of "Hi-Pot"?

That is FAR worse for the electronics than a simple Megger test..... and ALL good companies test their electronics for sensitivity in this manner.......notice I said "good!"

See here:-

http://en.wikipedia.org/wiki/Hipot

To quote from the first paragraph:-

Hipot is an abbreviation for high potential. Traditionally, Hipot is a term given to a class of electrical safety testing instruments used to verify electrical insulation in finished appliances, cables or other wired assemblies, printed circuit boards, electric motors, and transformers.

So a megger test should not damage anything in a properly designed machine, especially as the mains is used to carry signals in many countries and these are of a high frequency and high potential. Therefore a bad design will probably fail often......

Are you going to cover the cost of replacement when you are wrong?

Its already probably dangerous......or it stands a good possibility of being that.....any recommended way of testing should reduce the danger to the OP not increase it!!

Some of the tests that others have recommended were even more dangerous to the OP (You?)....

A megger is far less dangerous to both the electronics and the OP.....especially if transformers are used between the mains and the electronics.....remember a HiPot test goes directly onto the PCBs.....read the article I posted, it will possibly make you even more clever than you are right now!!!

....and you have the stupidity to ask me if I was to cover any possible costs of a machine with a possibly dangerous defect on it (its definitely you!)

If there is any worries, the OP should get a good electrician to check the complete installation.......as already mentioned by many here.....but he seems to want to do something himself....

Provided you only use a HiPot or Megger test between the active or neutral and ground you'll probably be ok, however, if you were to accidentally or by mistake put a HiPot of Megger across the active and neutral (as is done when testing house wiring) then it's good night to the electronics. Actually in many power line filters that are included in good quality appliances you will find a Metal Oxide Varistor (MOV) across the active and neutral after the appliance's fuse. The idea being that it will get rid of small transients that don't have too much energy in them otherwise the short the MOV produces should the appliance be supplied with an overvoltage situation will blow the fuse and thus protect the device.

By the way, those signals that are sent down power lines are definitely high frequency but they aren't high voltage, or at least they aren't in Australia.

I worked for several different large US computer companies from '73 to 2006, all of them had to fully "HiPot" their products before making them ready for sale, each and every unit......

As I guess they were properly designed (and maybe design failures in this area had already been corrected before I was around), I personally, in many months on the line in the USA, never once saw a piece of equipment show failures after the HiPot test.........

These were all state of the art (at the time anyway!) top of the line computer equipment......NO FAILURES IN MONTHS OF PRODUCTION, not a relatively ultra modern simple probably PIC controlled Samsung washing machine.

Now if you look here:-

http://en.wikipedia.org/wiki/Hipot

You can read that its a test possibly down to PCB board level, which is fully correct. It even mentions in the text similarity to a Megger test, insofar as the first sentence in the article says:-

Hipot is an abbreviation for high potential. Traditionally, Hipot is a term given to a class of electrical safety testing instruments used to verify electrical insulation in finished appliances, cables or other wired assemblies, printed circuit boards, electric motors, and transformers.

That is enough for me personally, why not for you too? Nothing you have posted has either changed my mind or caused Wiki to change their tune either, or to cause major companies to stop "HiPotting" their equipment.

It is a welknown and understood test procedure in a modern factory of high quality equipment.

Now I will admit that possibly substandard quality equipment may react differently/badly to a Megger or a HiPot test just as you say (that is also part of the reason FOR such tests), but I personally like and was very happy with all and any Samsung equipment I ever bought and found it well made, I would be sure that Samsung does not produce 2nd rate equipment........

Their head office in Germany was only a mile up the road from my company's head office, they had a great canteen and some great special offers for "walk-ins", TVs & HiFi stuff with damaged packing, but full guarantee......

I would not expect electronic/electrical equipment on a DH Mosquito to survive such a test....but some of that equipment may be almost 70 years old, so that is not quite fair!!

I hope we can drop this or at least you can cite some valid instances where correctly designed equipment is being damaged with a megger or HiPot test......

You might want to read some of the sites that I found after searching for "damage megger" on GooGle:-

http://www.tequipment.net/MeggerFlood.html

If you go here:-

http://wiki.answers.com/Q/How_megger_tester_can_damage_240volts_if_you_use_1000volts_range

You have the $64,000 question:-

How megger tester can damage 240volts if you use 1000volts range?

They are looking for answers! Can you supply a valid answer for them?

Without any proof of what or how it works, you simply reject insulation testing with Meggers and HiPot testing.......

• "I hope we can drop this or at least you can cite some valid instances where correctly designed equipment is being damaged with a megger or HiPot test......."

Actually things like dimmer switches have labels on them saying "DO NOT MEGGER" and I have also seen it on items like range tops and ovens for kitchens.

Anyway, I think we're misunderstanding each other.

In Australia before a new structure's electrical wiring is signed off they stick a megger across the active and neutral as well as the active and ground. The test is designed to ensure that the cabling hasn't been damaged during the installation (i.e. nail through cable, damaged insulation, etcetera), however, before carrying out the test they make sure that nothing like kitchen appliances are connected to the cabling so the high voltage doesn't cause any damage.

In your case of appliances being tested I'm pretty sure they don't apply the HiPot or megger across the active and neutral but rather the active to ground and possibly the neutral to ground. Such a test should ensure there is no way of power getting to where it not supposed to be and shouldn't damage any internal electronics.

However if you were to do the same test with the HiPot or Megger between active to neutral I'm pretty sure that it would damage the device. After all, if you take an appliance/device/machine that designed to operate on 110 V and hit it with 240 V the usual outcome is smoke and a non-operational unit. So if you were to put upwards of 1,000 volts across the active and neutral I would hazard to guess that similar damage, probably without the smoke would result. But active and possibly neutral as well to earth/ground/chassis is a different matter and shouldn't damage the device while ensuring that there is sufficient insulation/isolation between the power and where it shouldn't get.

Does that fit with what you have seen?

HiPot & Megger tests are always made relative to ground....there is no point to doing it between phase and neutral.......always testing the insulation.....

Do not forget, for a megger, phase to neutral may be seen almost as a short circuit.....even if only a single light bulb is connected and switched on......its job is in KOhms to MegOhms range......not Ohms!!!

Though some units do also have the possibility to measure low value Ohms as well, but that is not their primary "raison d'etre" so to say.......its a possible "Optional Extra!"

Have a great day.

"Do not forget, for a megger, phase to neutral may be seen almost as a short circuit.....even if only a single light bulb is connected and switched on"

Exactly, you have to make sure that everything is disconnected before you do the test. Actually we had to have it done on our house wiring when the power was disconnected for a couple of months while we were away for an extended period. It's really bullshit but before the power company would reconnect the power they insisted that they megger the active to earth and active to neutral. One of the things they sited was rodents munching on cables which I suppose is a possibility. Rats do like to gnaw on cables so there is a chance that they could have damaged the insulation while the power was off. If it was on then the damage would be instantly revealed when the bugger reached the active but with dead cables they could chew through everything leaving exposed conductors or even shorted conductors. Another possible problem is water ingress, again with power on the ingress would normally become apparent before it became too bad but without power on it could become quiet severe and cause a dangerous situation.

Anyway, I wasn't there at the time so I don't know what sort of voltage they used to carry out the test but I was informed that the cabling had to be checked with a megger (megohmeter) before they would reconnect the power to the house. Fortunately the house wiring passed but it did blow up the one and only dimmer switch in the house. After the test it was a case of full on or full off.

Probably the dimmer was not good quality.......Chinese or Taiwan maybe.....

I have a look at such units in case of a possible repair as in normal usage its usually the Triac.

With a Megger, it may be something else......that special diode (I have forgotten the name) that drives the Triac maybe.....or the chip that does the fun stuff.....

I hope that you have done all the possible diag.. but I like to remind if you have missed any point.

1. Instead of taking clothes just touch the drum. If you sense some shock then leakage is most probably in grounding the machine's metallic parts. Check all the metallic parts are connected to one common point and the point connected to your utillity ground.

2. If not then the load is expected to be electrostatically charged, which looks impossible as how dry those could be still wetness remains there which is sufficient to discharge electrostatics.

Have you ever noted that vehicle tyres contain a very small amount of carbon [may be something else now] to discharge your vehicle on road even in very dry conditions.

And vehicles carrying any combustible material additionally have hanging flaps to add to tyres function.

<< The tester shows current at metal bend of cold water inlet at machine side ..>>

Phase tester should not indicate if the machine is properly earthed.

Check all the wire links and your outlet socket.

Don't play games with any electrical compliance containing water. Get it checked by the supplier and check the grounding on your water supply. If you are using the hot water system to supply the wash machine check the bonding and grounding on the water heater. Remember, if you are measuring a current it means there is a fault, perhaps a high impedance fault which could become low impedance fault and KAPOW!

But maybe the potential is at the "cold water inlet" (pipe) - not at the machine. With old type electricity meters it was possible to steal electricity - electricians understand me. Some neighbour of the OP may do it now and the OP feels the result.

Not mentioned as a possible solution is the loss of neutral from the serving utility. If you are on a neutral grounded system and the neutral conductor is broken or lost, the unbalanced current will be forced to return to the utility via the grounding electrode system (GES). The GES is prescribed by the NEC and includes water pipe ground (assuming it is metallic), ground rod, concrete encased electrode, and other items if available.

I have seen 7-10 volts between devices and the water piping when this happens as the resistance of the grounding electrode system is higher than the neutral conductor. Locally folks were getting shocked when they adjusted the water flow in the show when standing on cast iron drains.

Just something else to check, but relatively easy. Good luck.