Tankless, instant hot water heater...

[jjj333]

I have got an big electrical problem!!! Could you respectable electrician experts please give me some much needed advice?
On eBay I bought a couple of these tankless, instant hot water heaters for use on 220VAC:

http://cgi.ebay.com/ws/eBayISAPI.dll...:X:RTQ:US:1123

Towards the bottom of this page they says that it has to be earthed (not on Neutral).
It heats up OK, yet the problem is that I measured about 100V between the water and (water input) copper pipe and (only) when I try to connect the earthing wire from the heater to the copper pipe, the automatic fuse goes off. The same happens if I try to connect this earthing wire on Neutral of 220V.
This hot water heater uses an open (uninsulated) resistor/ heating wire as element and water conducts. How to earth out the residual 100V?
Here it shows the inside of the heater:
about_us.jpg

Warm Regards from jjj333 in Chile

 

[Spa Key]

I'm not sure you should be finding 100v between the water & earth. The 'automatic fuse' I presume is an RCD? This detects any current leakage and trips for your own safety. You shouldn't try bypassing it in any way, especially where water is concerned. You don't just 'earth out' 100v for convenience. Either those heaters are faulty, or they're of terrible design.

 

[nickblake]

Um very confusing info according to the coral web site they are 110 volt and require a 15 amp mcb the ebay site states they need a 30 amp MCB mm for use in , i belive these are not suitable for connection to british electrical system look on it for the BS EN numbers if they donot have them i wouldnt use them

i have just watched the video DONOT USE THIS ITEM

 

[Sintra]

The op states that he is in Chile which has the same set up as the US but i don't believe he will get much help on here.

 

[UNG]

The Coral website is very confusing they don't seem to know the units load rating it quoted differently three or four times

That's enough to put me off

 

[jjj333]

In Chile we have got 220V and the units I bought ...are for 220V.
As mentioned, I put one of them to the test: it heated alright, when I input water from the garden hose, but... when I put my hand into the warm water outlet from the unit, I felt a light tingle on my finger tips. I then measured almost 100V with one probe (from multimeter) in the water outlet and the other onto the nearby water copper pipe.
The instruction mention that it's important to connect the earthing wire to Earth (not Neutral). The moment I did that the RCD safety fuse cut the circuit.
I think this unit is usually used in 110V circuit applications. Then this residual voltage would be only 50V.... at least half as dangerous as 100V. I touched this 100V shortly with one finger in the water and the other hand onto the copper pipe and got quite jolt!
Amazing that they are (in USA) allowed to sell such a lethal domestic appliance to consumers...

 

[Spa Key]

In Chile we have got 220V and the units I bought ...are for 220V.
As mentioned, I put one of them to the test: it heated alright, when I input water from the garden hose, but... when I put my hand into the warm water outlet from the unit, I felt a light tingle on my finger tips. I then measured almost 100V with one probe (from multimeter) in the water outlet and the other onto the nearby water copper pipe.
The instruction mention that it's important to connect the earthing wire to Earth (not Neutral). The moment I did that the RCD safety fuse cut the circuit.
I think this unit is usually used in 110V circuit applications. Then this residual voltage would be only 50V.... at least half as dangerous as 100V. I touched this 100V shortly with one finger in the water and the other hand onto the copper pipe and got quite jolt!
Amazing that they are (in USA) allowed to sell such a lethal domestic appliance to consumers...

Do they both leak 100v to earth? Have you tested both of them?

The RCD is tripping for a good reason. Don't put your hand anywhere near that water because you could end up dead. The reason they're meant to be earthed is for safety, so that if a fault develops the current has somewhere to go. There obviously is a fault, because as soon as you connect it to earth the RCD trips. If there wasn't a fault, you'd measure 0v between the water & copper pipe.

For the record, it's current that kills, not voltage.

 

[jjj333]

Yes, because they both have a 220V heater element inside and an earthing screw reaching from outside into the water.
Today I got a message from the technical support of this dangerous water heater:

"These units are very safe if properly installed, there are thousands installed for over 40 years and not a single casualty.
Your local water probably has a high mineral water an conductivity, however please try the following:
Do not use a circuit breaker with residual current protection as this will shutoff the unit., USE NORMAL CIRCUIT BREAKER 20 AMPS
and Ground the Unit.
You should only detect about 30 to 36 volts between the running hot water and the tap/
Try with another unit"
How should I respond to their letter? As a reply I prepared something like this, but maybe you have a more professional reply and so, I better wait and send the reply tomorrow (Monday 15th):
"Yesterday I called my electrician, who installed the whole electrical wiring and he explained to me: that the RCD is tripping for a good reason. I should not put my hand anywhere near that water because I could end up dead! The reason they're meant to be earthed is for safety, so that if a fault develops the current has somewhere to go. There obviously is a fault, because as soon as you connect it to earth the RCD trips. If there wasn't a fault, I would measure 0v between the water & copper pipe.
Thus, I am seriously compromised and don't dare to ask him to remove the RCD. He also mentioned that if for any reason the ground wire comes off, I won't survive the shower. Therefore, this water heater is in deed life threatening.
I have an installed Chinese tankless, instant hot water unit and no such problem with it. I trusted your product to be equally safe, but as it turns out it's not the case. Please be so kind to compensate me for the shipping losses".

 

[davejp]

I just watched the vid for that and started gettin worried by about a minute into it.

Then he started blatantly reading the instructions, getting himself confused and to top it off he then says a professional should install it!!!...

I'll pass!

Although there is a comment on the YT site saying "this is brazil, who cares about safety?"

Please let me know what else I should add as an effective responds.
Many thanks in advance for you good advice.

You could ask for a video demo of the bloke in the video to prove it is safe, Seeing him getting fried after that poor effort would be justice

 

[Gaz Bryan]

just had a look at the video on you tube. If you have a look at the similar videos down the right hand side of the screen there is another video showing a similar sort of unit affectionately known as the suicide shower. Nuff said.

 

[jjj333]

Here's, yet another model of their range of "lethal products":
about_us.jpg
In that video you can hear the (low volume) voice of camera man telling him to put the finger into the glass... to prove how safe it is. I am just amazed that they can they get away with this?

 

[jjj333]

Today I sent them back... but received yet another message from their technical support, saying:
"You have to use a regular breaker, and do not worry you will not be electrocuted, thousands have been installed in Brasil, Colombia nad USA and not a single electrocution, so Chile should not be an exception.
All the electric shower head manufacturers use this exposed wire element, such as Lorenzetti Brasil, Coral, Bocherinni, with an exceptional safety record".

So, they badly want me to step under this shower, albeit my electrician wants to save my life...
I'll let you know how this saga will end.

 

[jjj333]

You deserve to know how the "saga" ended: The eBay vendor refunded me the money paid, including both postages; i.e. the shipping they paid to send me the (5) water heaters and the return postage. What more do I could wish for?

The safety issue is to do with the Brazilian manufacturer of these units than with the resellers. Chances are the reseller is not selling these units on eBay anymore, because I don't think I am the only one perceiving the 100V leakage.
Thanking you all for your opinion on that product. It helped me to understand my electrician safety concerns, too.