Getting shocks off my 110v Mixer

[Kenny202]

Got a USA made 110v Kitchenaid mixer. All steel frame. PC board motor inside. Nothing touching frame etc that I can see. I have a fairly solid step down transformer which has done the job well for some time but only 2 pin on the mains side and a 2 pin outlet on the machine. Normally would be a 3 pin of course. Just noticed before getting a bit of a shock when I turn it on or touch the metal frame. Not like a full belt, but a bit more than a tingle I would say. Standing on tiles barefoot. 

 

I have converted as much as I can to 3 pin and all of our outlets are 3 pin (Renting home not owner). Believe it or not I am a qualified electrician but basically finished my apprenticeship and left for a different field 40 years ago. Is it possible I am getting shocks in the house from a neutral back feed or something? I mean even if an appliance is earthed you shouldn't be getting and voltage to frame from the appliance even if it is trickling away to earth right? I have lived in other houses here also had the same issues, tingles or zaps off any metallic framed appliances. For example I had a Macbook pro computer which runs off a 2 pin Power pack thing. Aluminum frame. Was getting tingles off it all the time. We are in an estate and I think the earthing is done outside at the post where the meters are. If I put a meter across active and earth I get a 220v reading so I assume this means we have an earth.

 

I was getting a zap off my electric guitar the other day plugged into an amp. The amp has a 3 pin plug, and the 4 outlet power board I was using has a 3 pin plug and 3 pin outlets, but after I opened it up there are only active / neutral connected to the actual 4 pin outlet housing lol. Doesn't even have an earth terminal. This was a factory made store bought power board!

 

I guess my first question would be is it likely a fault in the appliance / appliances or is the mains supply somehow creating a tingle / zap to frame? Keeping in mind get zaps or tingles off nearly every steel framed appliance we have, I think in every case where there was only a 2 pin plug. And of course anything not double insulated should have a three pin plug. But there shouldn't be currents trickling to frame anyway should there? Even if it is earthed correctly?

 

My Mixer as I said I plug into a 220 / 110v step down trx. normally with a transformer the secondary is completely isolated from the mains right? I have checked inside the mixer and as far as I can see everything is electrically isolated. The motor is steel and it is bolted to the steel frame so not sure if there is leakage there. I doubt it as the machine is quite new. Other than that there is only a PC board. There is an electrolytic capacitor which the body could be just touching the frame, but the end of the capacitor, not the electrical connection end

 

Any advice appreciated

[NCC1701A]

until you establish a ground connection from the blender to earth ground you will continue to get shocked. happens on everything in Thailand with no third ground connection.    

[lopburi3]

You have an earth but as you say it is not being used on your mixer because of the transformer being 2 pin.  Run a ground from frame of mixer (or use the original 3rd pin wire) and attach to a ground (you could run wire to a new plug and attach to the ground pin or just run to a ground rod like often used for refrigerator and such).  Computers often have to have a physical ground due to their power supply setup.  

[Kenny202]

9 minutes ago, NCC1701A said:

until you establish a ground connection from the blender to earth ground you will continue to get shocked. happens on everything in Thailand with no third ground connection.    

Respectfully why is that though? and I don't doubt you. I was under the impression the earth was there to provide an avenue for a frame fault and dead short / trip the breaker should a live wire touch the frame. Having an earthed appliance or no earth, how is the voltage getting to the frame unless there is a fault in the appliance?

 

By the way, on closer inspection it could be that the aluminum housing (at the end of the capacitor away from the terminals) of the reasonably large electrolytic Capacitor mounted on the PC board (I assume to control motor speed) could be barely touching the frame. The outside of the capacitor shouldn't be live or semi live though? Or is there some trickle?

Edited January 6, 2021 by Kenny202

[NCC1701A]

there is a difference of potential between you (a path to ground) and the blender. 

 

do this experiment. touch the blender with your shoes on. like running shoes. 

then bare foot. (if you dare) see if the intensity of the shock increases.  

 

if you are in a kitchen with concrete or title floor you will really feel a tingle. 

 

the same thing happens to me with the metal case of ALL my notebook computers until I got a ground rod and ran a wire to my UPS that feeds all my electronics. 

[Kenny202]

13 minutes ago, NCC1701A said:

there is a difference of potential between you (a path to ground) and the blender. 

 

do this experiment. touch the blender with your shoes on. like running shoes. 

then bare foot. (if you dare) see if the intensity of the shock increases.  

 

if you are in a kitchen with concrete or title floor you will really feel a tingle. 

 

the same thing happens to me with the metal case of ALL my notebook computers until I got a ground rod and ran a wire to my UPS that feeds all my electronics. 

I understand potential, but the frame of an appliance be it a mixer or notebook computer should be completely isolated from any electricity inside said machine. For you to get a zap off the frame their has to be some breakdown or fault in the insulation of the appliance somewhere inside surely? Like a new electrical appliance with a steel frame, that has the internal electrics completely isolated from the frame should have zero voltage leaking to the frame be it earthed or not? The earth is there as a safety / precautionary thing, not to trickle off excess frame voltage? Or am I getting something wrong?

[Crossy]

35 minutes ago, Kenny202 said:

Respectfully why is that though?

 

Capacitive leakage through the mains filter, slightly iffy insulation, magic.

 

You have a Class-1 appliance running with no ground, a potentially lethal (or as you are finding tingly) combination. Get that ground on there, you know it makes sense.

 

EDIT It's also worth checking if the output of your transformer is 120V reference to ground or 120v reference to supply live. It's certainly an auto transformer so you may score by simply reversing the supply plug. But you still need that ground.

[Kenny202]

7 minutes ago, Crossy said:

 

Capacitive leakage through the mains filter, slightly iffy insulation, magic.

 

You have a Class-1 appliance running with no ground, a potentially lethal (or as you are finding tingly) combination. Get that ground on there, you know it makes sense.

 

In this case Crossy I don't know that I can. Its 110v appliance running off a secondary transformer with a 2 pin outlet and 2 pin inlet. The appliance itself has an earth terminal, it just isn't connected to the 2 wire lead / plug 

[Crossy]

1 minute ago, Kenny202 said:

In this case Crossy I don't know that I can. Its 110v appliance running off a secondary transformer with a 2 pin outlet and 2 pin inlet. The appliance itself has an earth terminal, it just isn't connected to the 2 wire lead / plug 

 

Are you SURE the transformer isn't an auto-transformer? If it were an isolated secondary you wouldn't get a shock even if you got hold of one of the output wires (DON'T we want to keep you as a member).

[NCC1701A]

1 minute ago, Kenny202 said:

In this case Crossy I don't know that I can. Its 110v appliance running off a secondary transformer with a 2 pin outlet and 2 pin inlet. The appliance itself has an earth terminal, it just isn't connected to the 2 wire lead / plug 

run a wire from the earth terminal to a COPPER ground rod. about 150 baht at global house or home pro. use heavy gauge wire. that will stop the shock. 

[Lacessit]

Geezus, throw the bloody thing away and buy yourself a Philips blender. Plenty of them in Powerbuy or HomePro. Is your life worth the 800 baht it would cost you?

[transam]

7 minutes ago, Lacessit said:

Geezus, throw the bloody thing away and buy yourself a Philips blender. Plenty of them in Powerbuy or HomePro. Is your life worth the 800 baht it would cost you?

I tend to agree, there is probably no second chance getting a belt off the thing...

[Kenny202]

10 minutes ago, Lacessit said:

Geezus, throw the bloody thing away and buy yourself a Philips blender. Plenty of them in Powerbuy or HomePro. Is your life worth the 800 baht it would cost you?

Great idea 60,000 baht near new Kitchenaid commercial mixer. Why didn't I think of that 5555 ????

[transam]

4 minutes ago, Kenny202 said:

Great idea 60,000 baht near new Kitchenaid commercial mixer. Why didn't I think of that 5555 ????

Hmmmm, taking the death risk over a mixer.....????

[Crossy]

I'm tempted to lock this thread until our OP comes back and tells us he's installed a ground/earth on his mixer.

 

[Kenny202]

25 minutes ago, Crossy said:

 

Are you SURE the transformer isn't an auto-transformer? If it were an isolated secondary you wouldn't get a shock even if you got hold of one of the output wires (DON'T we want to keep you as a member).

I'm not sure if its auto or otherwise Crossy, here you go. I thought all transformers primary and secondary windings were electrically isolated but that's only what I thought. I touched the frame of the Trx don't seem to be getting any tingles. Bare in mind here, not doubting anyone at all. I am just trying to understand. I have also had earthing issues and tingles every home I have lived here on nearly all appliances and I am sure they didn't all have a breakdown in insulation or loose wiring inside. A new normally working appliance should have zero earth leakage. Otherwise RCD's would be constantly tripping out in newer homes. 

 

As I said as an Electrician I was a great Operations manager lol 

[transam]

My fridge/freezer is now 13 years old, it came with a 2 pin plug, we got minor belts off it, so cut the plug off, run a wire from the chassis, to a 3 pin plug. Job done, no more belts..

 

I was looking at electric kettles in Dohome a few days ago, most of them had 2 pin plugs, even the metal ones...????

[Crossy]

9 minutes ago, Kenny202 said:

A new normally working appliance should have zero earth leakage.

 

Here is one point where you are sadly mistaken. Any device with a mains filter (which is pretty much anything these days) will naturally leak to ground via the filter capacitors, leaving the ground off will allow the metalwork to float to about 50% mains (so 110V here), the source impedence is high so there's no risk of death but it's usually enough to get a tickle.

 

The leakage on IT equipment (PCs etc) is enough that UK regs only allow 3 PC / monitor combinations on a single 30mA RCD/RCBO to avoid unwanted tripping. Data centres with zillions of PCs avoid RCDs for the same reason, using alternative methods to mitigate shock hazards. 

 

From the photos it's impossible to tell what type of transformer it is, but odds-on it's an auto.

 

Just connect that ground and everything will be fine and dandy.

  

[Kenny202]

Guys I am well aware of the dangers of an unearthed appliance. Why I am on here trying to find a solution. One moot point is I think nearly every electrical appliance I have bought here with a 3 pin plug is what I believe the standard in Thailand, the twist plug thing, and ludicrously I have yet to see a home fitted with these points. I have changed most of mine to three pin plugs that will fit a standard outlet here. I mean some farang and Thai people here may have some idea of earthing but I am betting most don't which would suggest to me there would be 10's of millions of home and businesses here using unearthed appliances. I don't think it would be unreasonable to say the majority of appliances here would be unearthed. I mean selling electrical power boards with a 3 pin plug and 3 pin outlets and a 3 cable lead where the earth isn't actually connected? And how many houses here are properly earthed? Last place I lived in a proper estate the earth wires were all twisted together in the CB board and that's where they finished. There was an earth road outside the bathroom to connect the instant heater, with a power outlet under it....in the shower cubicle I kid you not 

[Crossy]

8 minutes ago, Kenny202 said:

twist plug thing

 

You mean a Schuko plug?

 

 

An awful lot of appliances had these in the past, the regulations weren't (aren't) strong enough to prohibit their sale. At least now the TIS plug is becoming standard and it fits in the regular Thai outlet with the ground actually connecting. You can get Schuko outlets (my workshop has many) but they're not exactly common beasties.

 

I really don't understand your reticence to just install a ground, either to your house ground if it's actually grounded or to a rod outside the window.

 

You are 100% right about the number of ground-free installation around Thailand, it's why we are forever hearing of people (often kids) getting killed by seemingly inoccuous objects, like your garden fence for flips sake!

 

[Kenny202]

6 minutes ago, Crossy said:

 

Here is one point where you are sadly mistaken. Any device with a mains filter (which is pretty much anything these days) will naturally leak to ground via the filter capacitors, leaving the ground off will allow the metalwork to float to about 50% mains (so 110V here), the source impedence is high so there's no risk of death but it's usually enough to get a tickle.

 

The leakage on IT equipment (PCs etc) is enough that UK regs only allow 3 PC / monitor combinations on a single 30mA RCD/RCBO to avoid unwanted tripping. Data centres with zillions of PCs avoid RCDs for the same reason, using alternative methods to mitigate shock hazards. 

 

From the photos it's impossible to tell what type of transformer it is, but odds-on it's an auto.

 

Just connect that ground and everything will be fine and dandy.

  

I don't doubt you Crossy. To be honest though I am not even sure what a mains filter is. Radio interference thing? So when you say connect a ground, how would I do that? Could I attach a ground wire to the frame of the transformer and run a 3 pin cable / plug to the 220v power outlet. That would earth the transformer at least. But what about the 2 pin plug on the secondary? Run a 3 wire cable from the mixer (earthed to frame), have a 2 pin plug to connect to the transformer and run the earth wire to the transformer frame which is already earthed on the primary side. Would that work? If you can see on the transformer it has like a metal plate foot. Would be simple to put a screw and nut to accept the earth wires with terminals on them. Sounds a whole lot more practical than running an external earth rod and cable.   

[Kenny202]

3 minutes ago, Crossy said:

 

You mean a Schuko plug?

 

 

An awful lot of appliances had these in the past, the regulations weren't (aren't) strong enough to prohibit their sale. At least now the TIS plug is becoming standard and it fits in the regular Thai outlet with the ground actually connecting. You can get Schuko outlets (my workshop has many) but they're not exactly common beasties.

 

I really don't understand your reticence to just install a ground, either to your house ground if it's actually grounded or to a rod outside the window.

 

You are 100% right about the number of ground-free installation around Thailand, it's why we are forever hearing of people (often kids) getting killed by seemingly inoccuous objects, like your garden fence for flips sake!

 

I'm not hesitant at all Crossy lol. Why I am asking you. Note the transformer has an inbuilt 2 wire socket as a secondary outlet. See previous post

[transam]

2 minutes ago, Crossy said:

 

You mean a Schuko plug?

 

 

An awful lot of appliances had these in the past, the regulations weren't (aren't) strong enough to prohibit their sale. At least now the TIS plug is becoming standard and it fits in the regular Thai outlet with the ground actually connecting. You can get Schuko outlets (my workshop has many) but they're not exactly common beasties.

 

I really don't understand your reticence to just install a ground, either to your house ground if it's actually grounded or to a rod outside the window.

 

You are 100% right about the number of ground-free installation around Thailand, it's why we are forever hearing of people (often kids) getting killed by seemingly inoccuous objects, like your garden fence for flips sake!

 

I cut those off and bought 3 pin plugs, I could never find what is meant to go into that earth hole, or perhaps there is nothing...

[Crossy]

Your transformer has a 2-pin supply plug, so there's no earth getting anywhere near it.

 

If you have 3-pin outlets replace the transformer plug with a 3-pin, run a separate wire from the ground pin of the plug to the transformer metalwork and then to the 3rd pin of the mixer or to the mixer frame.

 

This of course assumes that your outlet ground is actually connected to ground, you'll have to verify that.

[Crossy]

15 minutes ago, transam said:

I could never find what is meant to go into that earth hole, or perhaps there is nothing...

 

That hole mates with a matching pin in a French outlet, remember that plug is a European standard. In Germany there is no pin in the outlet, instead the ground connection is via the side connections.

 

[Kenny202]

Just now, Crossy said:

Your transformer has a 2-pin supply plug, so there's no earth getting anywhere near it.

 

If you have 3-pin outlets replace the transformer plug with a 3-pin, run a separate wire from the ground pin of the plug to the tansformer metalwork and then to the 3rd pin of the mixer or to the mixer frame.

 

This of course assumes that your outlet ground is actually connected to ground, you'll have to verify that.

That is exactly what I was suggesting.... and the home is earthed (I've tested earth to active) and all of my power board outlets are earthed. Like I said I bought expensive 4 and 6 outlet power boards as they had 3 pin plugs, cables and sockets. It is important to me as I run musical gear and without an earth there is always hum. Couldn't work out why I was still having issues until I unscrewed the actual power board to see it indeed had a 3 wire cable going to it, and a 3 pin plug...but there was no earth terminal on the power board! I have a funny feeling I bought them at Tesco too

[transam]

2 minutes ago, Crossy said:

 

That hole mates with a matching pin in a French outlet, remember that plug is a European standard. In germany there is no pin in the outlet, instead the ground connection is via the side connections.

 

I spent a lot of time searching for nufink then....????

[Crossy]

1 minute ago, transam said:

I spent a lot of time searching for nufink then....????

 

Yup. A Dutch friend runs this site, some very interesting stuff https://www.plugsocketmuseum.nl/EFhybrid.html

 

[Kenny202]

13 minutes ago, Crossy said:

 

You mean a Schuko plug?

 

 

An awful lot of appliances had these in the past, the regulations weren't (aren't) strong enough to prohibit their sale. At least now the TIS plug is becoming standard and it fits in the regular Thai outlet with the ground actually connecting. You can get Schuko outlets (my workshop has many) but they're not exactly common beasties.

 

I really don't understand your reticence to just install a ground, either to your house ground if it's actually grounded or to a rod outside the window.

 

You are 100% right about the number of ground-free installation around Thailand, it's why we are forever hearing of people (often kids) getting killed by seemingly inoccuous objects, like your garden fence for flips sake!

 

Yes the Shuko plugs. I have a Samsung Washing machine, a Samsung microwave and a Panasonic fridge that all had these plugs. They're major brands. I know, I cut the plugs off and replaced them. they are all under three years old. Many other items I've had with the jug cord type leads also same thing and still seeing them now.  

[StraightTalk]

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