Connect Earth to Neutral in appliance?

Hi all, I have just seen a 6KW 230V appliance that advocates what I believe to be a dangerous practice:
Internally: 1 - bonding together the three phase conductors to one LIVE
2 - bonding together the mains power NEUTRAL and EARTH
Externally: Connecting these two wires to the mains power source LIVE and EARTH conductors.
Am I right? Ithis dangerous?
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Appliances are things like hair dryers. A 6 KW device is a piece of industrial equipment!
Sheesh. What kind of goddamn appliance? Please give the type of appliance, manufacturer and model number. Also state what country, state or territory in which you are situated.
How can an appliance "advocate" anything? Did it speak to you? If so, increase your meds under medical supervision. Stay away from machinery.
Did you read this in a manufacturer's instruction manual or leaflet?

If we are talking about eg some kind of heating device with 3 separate heating elements, designed to be fed from a 415 volt 3 phase supply, I can imagine they could all be wired in parallel across a 230 volt single phase supply, although it is always better to run equipment from the type of supply for which they are designed.
A power draw of 6 KW at 230v implies a current of 26 amps. I hope you're not planning to plug this into a UK 13 amp socket! You'd need a separate 30 amp circuit, appropriately fused and switched.

Your use of the term 'earth' rather than 'ground' suggests that you are posting from the UK or a British Commonwealth country. However, it is important to clarify just exactly what we are talking about.
Power neutral is sometimes called 'system earth'. This is different from 'safety earth' to which any exposed metalwork eg a casing should be connected. If you connect them together inside the equipment you are risking all kinds of bad consequences, including shock hazard and fire.

What! Only two? Do you actually know what you are talking about?
Am I right? Is this dangerous?
For sure one thing is dangerous, that is your lack of knowledge. If you are trying to install a piece of heavy equipment on the cheap, ie trying to avoid the cost of employing a qualified and experienced electrical contractor, you are heading for grief and/or costly litigation. In whuich case I pity the people you have working for you, and I hope it's you that gets the "lethall" shock or gets burned up.
The name you have chosen to post under is interesting, and it makes me wonder if you are a troll.
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be a

In an installation manual for an air-conditioning unit.

Oh! So you think that because I think it is dangerous that I have a lack of knowledge and refuse to do the installation as described? You think then that I should go ahead and install the equipment? Connecting it between LIVE and EARTH? Perhaps you should go back and read my words. You obviously did not (or cannot) read.

Oh! I see. Semantics. Syntax. Word guru. Pedagog or pedant? This is not a literary forum and I am allowed to post weth any spolling mistakes and word constructions I wish to use.

So you doubt my real name (albeit misspelled for the NG)? http://web.telia.com/~u85920178 /
I was asking a serious question and looking for a little advice or support. The LAST thing I expected was a troll who just sits there behind the anonymity of his keyboard, slagging off everything anyone says without anything useful to contribute. If you have nothing useful to contribute then just keep quite. You obviously have little or no knowledge, otherwise you would have either understood, or asked for more info about a potentially dangerous wiring practice that has been published.
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Mate!! If you are even considering that it is possible to connect a 3 phase air con to single phase you are just demonstrating your lack of knowledge. Forget all the troll stuff etc. you are out of your depth sunshine !!
--
Cheers .......... Rheilly P



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con
The point is that I refuse to do what is stated in the manual, and I am looking for support. The manual is telling me that I MUST connect together three phases and connet these between LIVE and EARTH. I think this is totally unacceptable and dangerous, but I have been outnumbered by local "experts".
I know EXACTLY what I am doing, and that is refusing to to that which is described in an installation instruction.
If ANY instruction tells me to do anything that can result in a bit of kit having a live chassis after clipping one wire then that instruction is a load of bollox and I refuse to do it.
Local "experts" have produced 16 drawings for connection to different power supplies around the world, and 8 of those suggest bonding the EARTH and NEUTRAL posts together and using just one return. If that one return is disconnected thent he whole chassis will become live - whether I am "out of my depth sunshine" or not, I refuse to do it and I was hoping for some support.
Guess I will have to find another forum with someone who knows what they are doing.
Byee
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Why don't you tell us the make and model - somebody might be familiar with that item and be able to advise - You've already been asked once, but, no, you'd rather spout a load of crap. Why don't you CALL THE MAKERS or their local agents or stockists? Or call a local aircon installer? Dick.
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- Equipment model not yet released.
- I work for the makers.
Basically **they** have documented about 16 different power "configurations". All will get the gear working, but some are dangerous, or contravene regulations in different countries.
For example, in the UK one power regulation states that the consumer shall not bond together the Earth and neutral conductors in the consumer equipment. In the manual I have for review, at least half the configurations tell the end user to do just this.
Two of the configurations instruct the installer to connect the power between LIVE and EARTH.If you touch the equipment chassis and cut one wire then you will get killed. Again, this is illegal in many countries.
I have voiced my objections, but I am only one mouth, and a foreigner in this country, so my input is worth nothing! But if the document is published, and the equipment released, then I will indeed post the information here for your consideration.
I am just trying to avoid publishing a document that can potentially kill people, and I was looking for support, or reference to documents on the web that I could refer to. I think it is best that we forget it all for the moment - not your problem!
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On 30 Jan, 17:44, "Hairy Lethal" < snipped-for-privacy@hootmail.com (spellin mistaik)> wrote:> Basically **they** have documented about 16 different power

Then it may well be illegal to offer the equipment for sale in the UK. It has to pass the relevant EU & UK safety standards, and must be wired and operated in accordance with those standards.
The Electricity Safety, Quality and Continuity Regulations 2002
PART II PROTECTION AND EARTHING
General requirements for connection with earth
(4) A consumer shall not combine the neutral and protective functions in a single conductor in his consumer's installation.
I am not sure if including instructions with equipment that would result in a breach of the regulations, if they were followed, is a breach of the regulations, but I do know that In the UK, equipment like this ***must*** legally be installed and connected by a qualified person, who is expected to know enough to recognise and ignore instructions which would result in an illegal situation, and who would be liable in that event.
The Health And Safety Executive would be very interested in anyone proposing to ride a coach and horses through the legislation. You need not give your name. (If they are as bad as you say, they'll all be in chokey sooner or later. Do you want to go with them?) I would have thought that any illegal instructions would get picked up in the approval process, unless your employers are planning to sidestep that in some way?
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I Googled the info you gave and found the full document on the web. Many thanks, that is exactly what I was looking for - some reference information. I had found a series of BSI documents, but they were just instruction sheets for electricians, ultimately based upon the above document.

I do not think that is necessary now, but I shall bear this in mind if there is ever any recurrence of this sort of thing. I think that my basic problem is that I have a fair idea as to what is right or wrong, but I probably have more experience than the person/people who decided to offer so many **new options**. But then again, I am getting close to retirement.
Thank you once again for the info. It certainly lit a fire-cracker under my bosses arse :-)
Regards H
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I'm glad that you are not willing to follow the instructions in the manual-which don't make sense. Now find out more about the device before you do any connecting of any kind.
--

Don Kelly snipped-for-privacy@shawcross.ca
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On 1/30/07 1:33 AM, in article epn3d4$hkj$ snipped-for-privacy@news.al.sw.ericsson.se, "Harry

Complete and grammatical sentences would help a lot.
Bill -- Fermez le Bush--about two years to go.
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Please give us A. What country you are in so we can make some assumptions about the company's expertise in the real world.
B. Quote the full paragraph you are referring to so we can try and understand.
C. what is 230 volts? Phase to phase? Phase to neutral? or what.
A three phase device with 3 wires connected together becomes a ONE phase device so what do you mean? If it has 3 phase motor then it will just burn.
No civilised power system in the world allows the protective ground to be part of the current carrying wiring and is generally only connected to the neutral at the customer entrance point . NEVER within the equipment. -- John G.
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wrote:
| I have just seen a 6KW 230V appliance that advocates what I believe to be a | dangerous practice: | | Internally: | 1 - bonding together the three phase conductors to one LIVE | 2 - bonding together the mains power NEUTRAL and EARTH | | Externally: | Connecting these two wires to the mains power source LIVE and EARTH | conductors. | | Am I right? Ithis dangerous?
Could be. Maybe not. You didn't provide complete and clear information.
The way you worded the description is very poor.
Is this a three phase appliance, or does it merely have 3 separate elements that can be powered by three phases in balance when three phase power is available, and can be powered by the same phase if only one is available? You must understand what the appliance is and how it should be wired to know if it has been wired correctly.
Connecting neutral and earth is not good. That can be dangerous. But it is not as bad if the run of wire only serves the one appliance. It would be more dangerous if there is more than one appliance on that circuit.
--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
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be a

Yes, but I was a little "uptight" having last a couple of verbal arguments.

elements
The equipment has a 5-terminal connection for PE, N, L1, L2 and L3.
L1, L2 and L3 may be configured by another block for phase-to-phase or phase-to-neutral. This is not in doubt and is subject to clever design.

"contrex" above gave me the information. I Googled the full document and quoted it, chapter and verse to my employer. The designers have been informed, together with a full copy of this document :-)
The Electricity Safety, Quality and Continuity Regulations 2002 PART II PROTECTION AND EARTHING
BR H
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Please be a little more forthcoming with details.
Is this thing just a heater or does it have a motor or motors in it? You are very likely to get bad answers if you only 1/2 describe your problem. -- John G
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