220 VAC Electric Baseboard Heater Without A Ground

It is not ok, nor is it safe, here's why. The wire that you connected directly to the heater means that the entire heater element is always energized regardless of the state of the thermostat. Although no current will flow when the thermostat is open, any wiring on the switched side of the thermostat through the heater poses a shock hazard to the unaware.

If the heater element contacts the heater sheath then current WILL flow regardless of the state of thermostat, and the entire fixture will be energized posing a shock/fire hazard as current flows from the element, through the sheath, then onto the enclosure as the current tries to find a path to the bare ground wire.

Before anyone says "...No problem, the breaker will trip on the supply going to the ground...", it is important to realize that the heater element is only supplied with only half its normal voltage therefore only half the normal current flows; i.e., if the double pole breaker is rated at 20A only 10A (or less) will flow and it will NEVER trip.

The thermostat must be a double pole device that disconnects both sides of the supply, just like the double pole breaker in your breaker panel.

Wire it properly, a well trained fire investigator will discover this illegal wiring as he sifts through the ashes, and you will be responsible for the damage.

It is quite normal to wire 240V heaters with single pole line voltage thermostats and it is not in contravention of the code to do so.

The Canadian code, requires the device to be double pole only if it has an "off" position. Pretty sure the US code is the same.

Yea, I've worked on many baseboard mounted stand alone units and it was rare to find one that had a two pole thermostat switch in it.

I would say that the only ones I ever saw that had two pole thermostats were ones that had the stock single pole ones replaced. Some of those still only used one side anyway.

As for the OP, I think that if the feed line to the wall thermostat has a third ground line that tying in the outgoing lines third ground line to it should get him up to code on being properly earth bonded.

It's how I would do it and not think twice about it. It's no different than in a light switch or outlet that carries the ground line though its junction box.

Standard three wire dedicated double circuit feed setup rules apply as far as I am concerned and no reasons to complicate it over worst case scenario 'yea but' and or 'what ifs'.

You must also have a disconnect that can be seen line-of-sight from the heater....I always use stranded thhn wire for heat strips...I wouldn't trust romex....What size wire are you using and what size breakers, and what is the total amp draw of the heater? I would imagine the heater has an off switch that should be double pole....

100% correct.

The heater uses 5.3A, so the circuit is okay.

Oh that's just a small heater....never mind I'm sure it's ok....

LOL...

No disconnect. Breaker is 20A per hot. Wire is 12 solid.

One thing no one has mentioned is that the floor of your 2nd floor condo you think is ungrounded, that is wrong. Moisture & minerals combine to make most surfaces conductive on the surface, even if they don't conduct in their pure form.

It is likely your neutral is grounded intentionally, in which case an internal heater fault could make the metal components of your heater live to ground by 120V. It is possible that the current flow could be less than your 20 ampere breaker trip, and the heater parts then are a touch hazard.

With no preferential path to ground (your missing protective ground wire), which connects to your neutral to complete the circuit, it is possible your body might complete the circuit better than the wallboard or wood flooring that mounts the heater.

A double insulated heater is your best choice, though all I can find is a 1.5kW bathroom type here... http://consortepl.com/tuscany-1-5-kw-vertical-radiator-with-electronic-control/

I wouldn't use even a double-insulated heater, especially not in a bathroom where it could get wet and the water circumventing the double insulation. A grounded-frame heater could get wet as well of course, but with a grounded frame the current path would be internal to the frame.

What if the 220V AC is floating? I know that this is not how AC power is normally distributed. However, this possibility is exactly why I won't say that this has to be a dangerous configuration.

I will say that I dislike like answering if something is safe or not from only the information provided by a novice.

The 220 at the panel has a neutral. The wire to the thermostat has two hot lines. The old heater did not have a ground nor a neutral either.

Old-style, two-prong, unpolarised outlets and the things that plugged into them back then didn't either - and because of internal shorts twice nearly electrocuted me as result.

Not bonding/grounding the user-facing metal parts of anything plugged/wired into the mains is never a good idea regardless of its prior history and/or lineage. It was dangerous then and it is dangerous now. It is only by the grace of God that I'm even able to write you this. Please do yourself and everyone you care for a huge favor and ground it.

"The heater manufacturer recommends the heater to be grounded."

So what you are implying is that a dangerous installation has been replaced with a new dangerous installation, but its OK to do that?

There is another blog here somewhere, where a water heater element, was only switched on and off with a single phase thermostat (2 wires only). There was a breakdown on the heater itself, often due to corrosion, producing pinholes and letting the water in.

Due to the fact that many circuits in US houses use an incoming single 220VAC phase, (often wrongly called 2 phase, even by so called professionals!!!), which is grounded to supply a neutral for 110VAC loads, there is on the unswitched side of the heater 110VAC, now passing through say half of the heater element (heating it up), exiting at the pinhole and via the water, through the mountings, into the fabric of the house, brickwork etc., which is a very poor but effective enough ground.

Effective enough to cause a shock! Maybe even to kill someone....

A proper RCD would catch that, even without a "proper" ground, but more to the point, the insurance company will not honour any damages, if not installed to PROPER code.....

That its often done is not a let out......remember, any neutral/ground center taps on that 220VAC single phase, even in a neighbor's house, canl still cause the problem!!

In countries where 50Hz 240VAC are the domestic supply, as long as the single live feed (the other is the neutral/ground) is switched by the thermostat, this cannot happen.

Hi Andy, I'm implying that I think it's a safe installation, even though my gut feeling is that it isn't wired per code.

There isn't a ground anywhere near this heater - it's not a water heater, it's a baseboard wall heater. There isn't a neutral anywhere near the heater either. Maybe 7-8 feet to the nearest outlet and 8 feet to the circuit breaker.

I don't think it's dangerous, or I wouldn't have done it. I hope you can understand.

Firstly, it is dangerous.

The minimum you need is a two pole RCD.

Also, as far as I am aware, there MUST be a link to both the transformer Neutral and ground lines, to your Condo...how else would you get 110VDC?

Adding a link inhouse, to neutral, and calling it ground, is what was used in Germany many years ago. I don't like it and I don't know what you code, any of them, would say about that!! But it would be a tick safer if properly done....

But I have to admit (been informed here by other CR4ers), really old code in the USA was totally dangerous, and it varied from place to place!!

I can only say that if you have the slightest interest in keeping family, visitors and pets safer, go for the latest code......it has got that way through experience, usually bad......

Anything less than the latest code is really not showing good sense......

1. Your definition and my definition of dangerous are not in agreement. You can call it dangerous, but I don't.

2. What you call RCD is what we call GFCI. The best I can tell you about our GFCI requirements are that we need them when an outlet is less than 6 feet from a water source, or any kitchen outlet.

3. I don't think a GFCI will help. Here's what I pulled regarding GFCI operation "These electrical wiring devices are designed to quickly and automatically disconnect a circuit when it detects that the electric current is not balanced between the energized (line) conductor(s) and the return (neutral) conductor. Under normal circumstances"

4. Since I don't have a neutral, I don't know how the GFCI will trigger.

5. We have a Neutral line in the fuse box and to the outlets and light fixtures. The 220 line doesn't need a neutral, right??? Therefore no neutral going to the baseboard heater.

6. I think it would be great if everyone could afford to bring their properties up to code. The fact is that the costs are high, so we have to make choices. I could pay an electrician to rewire my condo and four of my rental homes (three houses don't have grounds and one has copper clad aluminum wire in the walls). $25K or so to do all of them. Then there's asbestos, wall sheathing, foundation, plumbing, HVAC, windows, insulation, roofing, seals, etc. To bring all my houses up to code may run me $1M. I'm not spending that much to bring them up to code.

You appear to have simply little understanding of electrical systems and some of your points here demonstrate it time and time again to anyone with a reasonable knowledge.

I was determined to stop posting in this cartoon of stupidity, but have decided to try, just one last time, to get you to understand.

1. Your definition and my definition of dangerous are not in agreement. You can call it dangerous, but I don't.

So your "lack of knowledge" decision is correct?......in my lifetime, when I (and I am sure many others here) "help" people to make installations safe, their attitude was many thanks and they got the problems fixed.

2. What you call RCD is what we call GFCI. The best I can tell you about our GFCI requirements are that we need them when an outlet is less than 6 feet from a water source, or any kitchen outlet.

The reason I stay with RCD as a name, is simply because a good source of information, Wiki uses it as the "main" name, therefore easily found. You have apparently read a US definition about wet areas, but as certain people here have mentioned, time after time (not just me!), you don't need a "wet" area, to find a part (usually all) of a building, that is grounded (it does not float in the air like in star wars?) and therefore a possible path for an electric shock for a human or a pet.

This might even change with the seasons for some obscure reason....

3. I don't think a GFCI will help. Here's what I pulled regarding GFCI operation "These electrical wiring devices are designed to quickly and automatically disconnect a circuit when it detects that the electric current is not balanced between the energized (line) conductor(s) and the return (neutral) conductor. Under normal circumstances"

A RCD/GFI will always help, as many here have said, again, time after time, as it detects an imbalance in current between the live and the neutral (or in a 220V situation, between live and live!!). Caused possibly by a living thing, or even a fault that could cause a fire. Both are covered by an imbalance of current.

Remember, in old installs in the USA, one side of the 220VAC phase is not always broken by any other safety device!!! Eg. The fault current might only be limited by the mains fuse (assuming nobody has "repaired" it with foil or thicker wire), and substandard wiring can easily catch fire, INSIDE WALLSEVEN!!!

4. Since I don't have a neutral, I don't know how the GFCI will trigger.

Using a single phase 220VAC (as in this case!), does not preclude using a dual RCD. It will monitor (already mentioned here several times!) the currents between both legs of the phase AND IF THEY BECOME UNBALANCED, REMOVE BOTH CONNECTIONS AT EXACTLY THE SAME TIME, ONCE THE UNBALANCED CURRENT EXCEEDS THE SETTING......

They do not NEED a neutral!!! A neutral is ONLY part of the circuit for 110VAC supplies, therefore it is checked for balance then!! Even simple high school physics should tell you this much......the electrons have to circulate!!

You apparently only read into information, that which you understand, and ignore all that you don't understand!!!

5. We have a Neutral line in the fuse box and to the outlets and light fixtures. The 220 line doesn't need a neutral, right??? Therefore no neutral going to the baseboard heater.

Understood, but again, an RCD does not need a neutral. It just needs a little common sense and to be installed.

As I said several days ago, THAT IS THE MINIMUM YOU NEED, EVEN THOUGH IT WILL STILL NOT BE "MODERN" CODE.....BUT FAR BETTER THAN NOTHING AT ALL...

6. I think it would be great if everyone could afford to bring their properties up to code. The fact is that the costs are high, so we have to make choices. I could pay an electrician to rewire my condo and four of my rental homes (three houses don't have grounds and one has copper clad aluminum wire in the walls). $25K or so to do all of them. Then there's asbestos, wall sheathing, foundation, plumbing, HVAC, windows, insulation, roofing, seals, etc. To bring all my houses up to code may run me $1M. I'm not spending that much to bring them up to code.

You freely admit to having several areas of extreme danger to the residents, in your properties, and admitting it here publicly, so you apparently like living/renting out dangerous housing, and owning such properties.....but they were cheap I guess!

But if they were brought up to correct levels of safety, surely the USA "supports" such work in some way, (here you can set it off against taxes for rented properties) and you could also then charge higher rents!

Or are they simply in such really bad inner city areas, that only the lowest of the low want to live in them?

Remember, if anyone living in them gets ill or dies and they or their families take you to court, (maybe with extra help from the police investigators) it could cost you millions, or better said, everything you own!! EVERYTHING!!!

If someone actually dies, you could even end up behind bars for many years!!!

Do you need that?????

You should pick the worst property and get it up to code in all respects. Once that is done, start on the next one, or better still, simply set fire to them all (Oh sorry, they are already at risk of doing that with no help from you!!)

70% of the world's lawyers live in the USA I believe, you and others like you could even be one of the reasons why, I feel. A good hunting ground for lawsuits.....

Well said. GA

You have explained precisely why I dread answering any safety related question on a public forum. The OP (Autobroker) is looking for our blessing in their cost driven conclusion. Jacob Marley would be proud of the OP's conclusion. I am pleased that the CR4 chorus refuses to bless this blatant disregard of electric codes.

What still baffles me is why anyone asks for advice when they have no intention of accepting it. Are they looking for an argument?

Thats a really good point!!!

What does Judge Judy always say? "Beauty fades, dumb is forever!"

This blog feels like its been going on forever......

See post 73

Agreed fully, without it bonded, all bets are off. Which is why I told him not use it till it is bonded.

I used three existing thermostat which doesn't have an off switch, however if the knob is turned far t to the left there's a click and its off.

Doesn't (almost) every thermostat have an "off" position?

No...

What is with the "Off Topic" thing? How is that comment off topic?

I get what you're saying, but there isn't a ground wire nearby. There's a ground wire in the Romex, but it's not connected to a ground. There also isn't a neutral nearby. The risk i see is ifa short forms and the case becomes hot and then the other hot somehow shows up at the thermostat and you touch both the case and thermostat at the same time. Extremely unlikely, so that's why i see very little risk. Or am i missing something?

The risk I can smell is that the ground of the heater builds charge with respect to the floor and if not wearing the proper isolation footwear, an ESD is likely to occur. I would dig a hole in the soil of your garden, stick some metalic nail in it and connect it electrically to thw ground of the heater.

BTW, this post does not belong to general discussion but to Electrical Engineering.

"The risk I can smell is that the ground of the heater builds charge with respect to the floor and if not wearing the proper isolation footwear, an ESD is likely to occur."

Um...no. This is a heater, not a Van de Graaff machine.

"I would dig a hole in the soil of your garden, stick some metalic nail in it and connect it electrically to thw ground of the heater."

That would be a "Hell no."

"BTW, this post does not belong to general discussion but to Electrical Engineering."

Maybe, maybe not. This is an electrical safety problem but not necessarily an electrical engineering problem.

GA

I see that you say this is in a, " Condo " . Where I live a Condo is like a Town house, Town home, 2-3 bedroom attached home similar to a duplex or triplex.

I am guessing that you have outlets ( duplex ) and single and double throw light switches, all of your outlets and switches should be grounded, that is 2 conductors / black-hot, white-neutral, + a ground lead ( wire) , the ground can be either bare or sheathed.

So, if your outlets are grounded and your switches are grounded, then you should be able to attach a ground wire from the heater frame through the metal utility box to the same ground lug on one of your outlets.

Here is another suggestion:

Go to Amazon, order a copy of, " UGLYS " electrical reference / Jones & Bartlett publishing. I recently got my 2017 edition, it cost about$20.00 USD.

Using the ohm's law calculations ( simple linear algebra ) and the guides in the book, you can determine the required information to safely wire up your heater.

UGLYS is a teaching book, it will show you how to do the calculations.

If you do decide to call an electrician, by reading this book, you can better understand, the how's and why's, when the serviceman does his job.

Yes, it's a condo like you describe. Neighbors below and to the back and side. The outlets are not grounded not are the light switches. The heaters are also not grounded, all five of them. The hot water heater also isn't grounded. The only thing grounded is the washer and dryer that I wired up years ago.

That installation sounds dangerous. Much like the installs in Germany just after WW2.

A socket, has a live and a combined neutral/ground, so they used to wire EACH AND EVERY SOCKET a neutral and ground link.....

But in the USA, many devices only have a 2 wire cable, BUT have to be double insulated! Eg. No metal frame.

Water heaters and many other metal framed devices (white goods!) ARE NOT USUALLY DOUBLE INSULATED!!! Which is why a proper ground is needed.

I doubt that the link as used in Germany after WW2, would be allowed in the USA....but still better than nothing, but no RCDs then allowed, as they would immediately trip I believe!!

Your entire condo electrical system is un-grounded?

Do you know how easy it is for a duplex receptacle or a light switch to develop a short?

I think I would move out of that place.

GA

Best comment recently made here......

Older codes need to be ignored, much has been learned over the years.

In this case, the condo needs to have RCDs or local equivalent installed as a minimum......for all circuits.

Though if the other condos are on the same phase, this might get VERY annoying......seen that in the UK many, many years ago!!

I don't live in the condo.

I also own three other homes that do not have grounded outlets nor grounded light switches. All the light fixtures aren't grounded as well. The neutral = ground at the circuit breaker and there's a metal rod pounded into the ground that's the "ground".

Remember that most homes in the Western US built in the 1950's and earlier did not have grounded outlets and switches. Most are still standing and the number that were burned from electrical problems are very small.

Thanks for the recommendation for Ugly's Electrical Ref book. I saw one of these a few years ago and it's awesome! I forgot about the book.

Great advice! Thank you.

I just ordered a copy of the 2017 Ugly's elec book. Thanks again.

There are many fine teaching books on how to do brain surgery. I can buy them, I can read them, I can watch them on YouTube, I can even do simulated surgeries on my computer, but I think I'll leave the actual procedures to the professionals. The money saved isn't worth the risk since "dead is dead" regardless of the cause.

Maybe this information will be helpful. Almost nothing is grounded in the condo. There are five other heaters that don't have a ground. The thermostats aren't grounded either. Years ago, I wired up a washer and dryer plus a light and switch. At they time, I installed a ground, but only to those circuits.

This condo has been around since the early to mid 60s. .I haven't heard of any stories of people getting shocked or electrical fires. I completely understand that it should be grounded per the electrical code, but if nothing nearby is grounded, nor is there a natural ground, what is the risk of shock? Not some hypothetical risk that has a near zero chance of happening, but a real risk. And how would the current complete the path? There is no ground or neural nearby. Please, only respond if you understand home wiring and electrical systems. Thank you.

Two adjacent items, both faulty, plugged into separate branch circuits each on its own phase. 220 volts between them.

I get where you're trying to go with it, but how does someone get shocked by this? There's no way anyone including Shaq has long enough arms.

I have seen split receptacles where one half the outlet was fed via a wall switch (for a table lamp) from from one branch circuit whilst the other half was unswitched and fed from another branch circuit on the other phase. 220 volts between them. Shaq's finger and thumb would do.

Wait, aren't we talking about the installation of my wall heater and the risk of how it's been installed?

If so, then why bring up split receptacles? My response was simply saying that nobody could touch the heater and a neutral or ground nearby.

There's a chance you could be vacuuming or using some other portable electrical device and touch both....but I wouldn't worry about it, what are the odds? I mean everything is a risk in some way...why should we try to eliminate risk, it makes life more exciting...well until somebody else gets hurt, then it sort of becomes your fault...and of course you can't never undo it....

I get what you're saying and I'm here looking for answers, so your post does help. I looked at what I saw as potential risk and how likely it was to happen (what would need to happen at the same time). I then looked at the cost to run a new line of Romex from the circuit breaker to the thermostat.

So far, nobody here has given me a good enough reason for running a new line to the thermostat - if someone here had information, such as; "the heater you installed is at risk (60% of the time) to develop a chassis electrical fault after 30,000 hours of use." That's what I'd like to hear.

There HAS TO BE A NEUTRAL GROUND, HOW ELSE WILL YOU GET 110VAC to sockets for example?

It seems like many here have made the assumption that there are 110V outlets near the heaters. There aren't any.

This is one of the reasons why I don't see a big risk of shock, but again, I could be wrong.

Someone here posted something about capacitance, but others said he's wrong (and I agree with them). I'm not sure what else could cause a shock?

See Post 73

Most light switches in a house last about 20 years, over time, the contacts wear out, repetitive usage and expansion and contraction. When the switch wears out, the mechanical operation can become sloppy, I.e. the switch feels loose, sometimes it will work, sometimes it won't, sometimes there may be visible arcing. The same things happen to a duplex. The ground is designed as a safety measure.

If the switch was to completely fail and power was to shunt to ground ( that is if you got ground wires attached ) then the circuit breaker would trip or a GFI connected device would trip ( open )

Now if you don't have a ground wire attached, then if the switch or duplex failed, current could flow through you in an effort to find ground ( earth ).

Sounds like you should get the whole place wired up right.

Maybe your neighbors will follow suit.

The switches aren't original, nor are the outlets. The thermostats are original and same for the heaters.

When I took the thermostat to Home Depot (I needed a new trim plate), the guy there told me that he doubts I'll find another plate. He asked to look at the thermostat and asked how old it is. When I told him, he remarked that they just don't make things like this anymore. I've installed thermostats in my other homes and I know what he means. This thing is a tank!

A few years ago, I did change some switches and outlets that may have been original to the home (built in the late 50's to early 60's). They were much better made than the new stuff out there and they were rebuildable (had screws so you could take them apart). The only problem is that there probably aren't many replacement parts. Being an engineer, I took one apart and I was surprised by the quality of the parts. Even the metal parts inside the switch were thicker and soild.

Living in our disposable world, I think it's such a shame that we don't make things that are built to last.

" This thing is a tank " . I go to estate sales ( garage / yard sales ) several times a month, the seller will have an old drill or circular saw for sale, manufactured in the 1950's - 1960's, these old tools are built like a tank, being that they are all metal construction, which is quite heavy.

The corded plug is usually two conductor. When you disassemble one of these old tools, you discover that the metal body of the tool is electrically isolated using bakelite plastic and non conductive paperboard. The inherent danger with this design is that over time, the bakelite insulators develop cracks, and current can flow through the cracks toward the metal body of the tool. As for the paperboard, it also becomes dry and brittle over time, then, due to mechanical vibration, among other factors, current will leak through the paperboard.

The reason old switches and duplexes were manufactured with screws was because people who lived in rural areas needed a way to repair this device. You may have heard of the term, " farmers logic " , farmers, who lived a long way from the nearest general store, had to be innovative when they needed to repair something that broke on the farm, remember, a farmer had to go to a general or implement store to buy a part, and if the store didn't have the part, then it had to be ordered from a catalogue, this meant that it could take several weeks to receive what he needed.

Today, we have stores and distribution centers located just about everywhere, if you need a part in the morning, you can usually have it by the afternoon, and if it can't be delivered by truck, then there is always the plane, helicopter or air drop by parachute.

"The inherent danger with this design is that over time, the bakelite insulators develop cracks, and current can flow through the cracks toward the metal body of the tool. As for the paperboard, it also becomes dry and brittle over time, then, due to mechanical vibration, among other factors, current will leak through the paperboard."

Yep.

That's what nearly killed me when using dad's old electric hand drill: the internal insulation was faulty and, as the drill was normally stored in the basement, things got damp - and conductive.

The other time I was nearly electrocuted was when using an older, two-wire trouble light having an unpolarised plug. That 'rod-type' switch that you pushed from one side to turn it on and pushed from the other to turn it off? The tip had broken off and the metal center was now exposed. The metal bit was either connected to neutral or to hot depending on which way the light was plugged-in. I had my left hand on a metal pipe and went to switch on the light with my right - and got the shock of my life.

If they don't follow suit, they should at least file suite.

I'll just be honest:

After reading all these comments and your replies, I am now wondering why you posted the question in the first place?

Now I could be wrong, but my impression is that you have no intention of changing a thing regardless of what anybody says and possibly didn't from the outset? For better or for worse, that is my impression.

May I ask why posted the question? Are you looking for someone to assure you that what you did/plan to do is okay, in spite of the fact that you yourself noted in your post that the manufacturer recommends you ground the heater?

I want to know if I missed something. I didn't ask if it's to code and I didn't imply that it was. The replies I received are missing the mark, but I've seen it happen here before, so it doesn't bother me. Just a simple response to correct the assumptions that were made. I don't see the harm in it.

I do want to know what can realistically go wrong and if someone has actually seen something bad happen when a heater is wired up like this.

If someone can tell me that their home (relatives, co-workers, etc) was destroyed in a fire or someone was electrocuted because x,y,z, then I will find a way to run a ground wire to the heater. If I made a mistake and I'm putting someone at risk I want to know.

I hope you can understand why I asked the question.

Fair enough.

So you think the electrical codes are superfluous...?

Some are. Same as some of our laws.

I'm back on my desktop, so I can do this now. Here's the installation manual and I did wire it per the instruction - see single pole thermostat. http://www.homedepot.com/catalog/pdfImages/c2/c2ef6436-8725-4f63-95fc-b856f444fb10.pdf

In all cases a ground is shown.

From the instructions you supplied: 1. All electrical work and materials must comply with the National Electric Code (NEC), the Occupational Safety and Health Act (OSHA), and all state and local codes. Regardless of what is posted on this forum, you are the responsible party in the event of any malfunction of the equipment!

This is similar to the question, "How do people get electrocuted in a fiberglass bath with plastic plumbing?" As i understand it the capacitance of the bathwater is enough to stop a heart, after all it takes bugger all to do that. If so, the answer to your question is that the door frame, floor, pipework, heck, even the wiring itself may provide enough -ve potential to allow a faulty heater/appliance give a boot. It has been law for many years in OZ for everything to be earthed ( our term for grounded or bonded ) even light fittings, unless the devices are double insulated. Jim

It's not the capacitance of the bathwater which is comparable to the capacitance of the human body (think 'carpet shocks'). The water itself is the conductor.

As long as there is a continuous wet path to ground, either through the pipes or over the surface (or both), the bath and plumbing don't have to be conductive. Even if the water is clean it can still be quite conductive, especially if it has high mineral content. It doesn't take much current to be lethal; 100 - 200 mA will do.

It needs to be mentioned that the method in which someone gets shocked by a voltage introduced into a body of water, such as in a bathtub, is not always the same methodology as someone coming between a hot conductor and a ground conductor.

The following is taken from a rather large thread about a IPhone charger killing a young Russian girl in a bathtub. That thread is found at...

http://cr4.globalspec.com/thread/99480

"As previously discussed during a thread about drowning deaths in marinas caused by victims being immobilized because of an electric shock.

When an energized conductor falls into a body of conductive water and that body of water has a path back to the source of potential (through the piping), a potential field is radiated into the water starting at the point of contact of the energized conductor with the body of water. The intensity of that field decreases the further out from the point of contact. This is the same issue known as "step potential".

When a person is placed in that field either by swimming at a marina or as in this case, in a bath tub, the "potential" difference of the field between the front of the body to the back of the body will generate a current flow across the body relative to the resistance of the mass of the body.

Many tragedies have occurred in marinas. Several young people drowned as the current flow paralyses them completely so they sink under the water and drown. It is reported that the ability to breath is also impaired by the locking of the chest muscles."

Yes. It's the voltage gradient (and its associated current) that kills. Someone sitting in a tub of water at voltage will not be electrocuted if there is no current path (neither through them nor the water) and therefore no gradient.

In the comment to which I was responding, the commenter mentioned the capacitance of a tub of possibly being the culprit in the case of non-conductive piping and tub. I pointed out that the water itself is the conductor provided there is a continuous path to ground. The voltage source doesn't even have to be overt, such as someone using a hair dryer in the tub. For example, a kid splashing in the tub with the water running. Nearby is an ungrounded electric baseboard heater installed in accordance with early-1960s standards.

The water from the facet makes a continuous stream from the faucet to the tub water. There's your ground connection, plastic tub & piping or no.

Meanwhile, water splashed onto the floor from the back of the tub meets the ungrounded frame of the baseboard heater nearby. The water gets inside the heater in contact with its wiring and/or heater has an internal fault such that the frame is at line voltage. The current now has a path across the wet floor, up the tub and wall, into the tub water, through the kid and voila! A funeral a few days later.

And that, boys and girls, is why you should never pee on an electric fence.

^{_{(Sorry, I just thought I'd inject a little levity amid all these well grounded statements)}}

Probably why my little brother never had kids. He not only peed on a 'weed-burner'-type electric fence, but also on the spark plug of our (running) lawnmower, the grass, mower wheels and his Keds being especially wet from the mowing. My 'lab' (a second-floor porch screened-in on three sides) overlooked the back yard and I was out there working. I reckon he'd thought everyone had gone with mum to the store and so felt free to do his dastardly deed. He didn't know I was home.

I heard the mower going back and forth and then it stopped moving but with the motor still running. I paid scant attention until I heard him scream and I rushed to the screen and yelled "ARE YOU OKAY!!" There he was, arseward, pants down around his knees. That mower had a very healthy magneto, but I'm not sure which horrified him more: that there was a witness to his utter stupidity or that the jolt blew his monkey out through his arse and into the next county.

I hope he's handsome cause you seem to have gotten the brains of the family.

We're all pretty handsome, actually.

LOL!!

You sound like someone who has tried it!!

Is this you some years ago?

Are U Pissed off?

Andrew... welcome to the forum by the way. It looks like you will be a regular contributor. Good.

I saw nothing wrong with your post, I just wanted to make sure that the idea of the human being parallel to the circuit as opposed to being in series with it was understood.

Thanks!

Excellent analysis...... GA!!

You're right on the mark. A few years ago, I knew of someone who was killed when a faulty extension cord "electrified" the water around their boat dock. He went in the water, not knowing the cord was bad and wound up getting electrocuted. GA to you for explaining it so well.

In the pdf I could not find one, so I gather it is not double insulated.

I have personally never seen an affordable double insulated water heater...

It's not a water heater.

Sorry I misread.

The connections for the isolation transformer will then be in-between the baseboard heater and its 220 supply coming out of the circuit breaker(s)..

thanks.

I've never heard about this square within a square symbol here in the US, so I looked it up. You are correct, it's the symbol used to designate an item is double insulated. Based on what I found, it's something used in Europe. Thanks for the info.

Simple answer is NO.

Furthermore, leaving a live connected, in the USA and similar areas, is often the cause of water heaters boiling, when there is a ground fault somewhere on the element.

You need as a minimum, to break BOTH hot wires....If the thermostat is single phase, maybe a small contactor controlled by the thermostat?

For the safety of personnel, you should place one of these in circuit, even before the thermostat, that is nearer the supply not the load:-

A two-pole, or double-pole, residual-current device. The test button and connect/disconnect switch are colored blue. A fault will trigger the switch to its down (off) position, which in this device would disconnect both conductors.

But this does not protect from overcurrent on its own!

There are some that do that as well of course.

This one only prevents electrocution for personnel and pets, who make contact with a live pole.

I have to admit that I am not 100% sure that this one will cover both live pins in a US single phase 220VAC installation, but better brains than mine here will let you know!!

I believe it will and certainly there are RCDs for the single phase 220 v system, in domestic and office installations, even if this is not it!!

Remember 2 x 110VAC = 220VAC of course!!

The picture was found here:-

Residual Current Device

Er, um, that particular one is rated 0.1A. The one that <...prevents electrocution for personnel and pets...> is rated 0.03A.

Just sayin'.

GA

I never looked at the fine print. You are of course 100% correct. Thanks.

A few years ago, I had to change a contactor in my HVAC system at my home. A contactor is a high current relay, correct. Based on my understanding of what a contactor does, how will it help my situation?

That post you answered, was more about RCDs than contactors.

But a contactor allows low current devices to control high currents for example, and or high voltages, or completely different voltages, DC controlling AC for example....its simply a giant relay really.

They also allow a single pole switch, relay, thermostat, to control say two lines (or even three!). For instance, both legs of the 220v phase, so that neither can supply a live to a device, (except when it is working correctly of course).....which can be highly dangerous at any time.....and any good E.Code will prevent such happenings.

RCDs are good in that if there is only a "tiny" leak of power from a supply, say through a human or pet for example, it drops power immediately. It does not need a fuse or breaker to actuate....but its still painful!!

BUT, it does not guard against over current, unless this has been added.....

I personally prefer that a House/Condo, has one per phase line in a US domestic situation, that is two. Then each circuit has its own breaker for overloads.....my house has 3, one for each phase.

There is a large amount of "resistance" in the USA to RCDs, even though (I am told) "NEW" code requires them!

They are a great addition to ANY property, old or young!! That is if you really value your family in the slightest!!

If you still have questions, simply ask....

Maybe the US is resistant to RCD's because they run BOTH 220v and 110v on the same circuit. Would an RCD trip as soon as a 220v appliance was turned on?

All an RCD "cares about" is that the vector sum of the currents is zero. It could be out through one phase and back through the other, or back through neutral.

If the sum is non-zero, it means some current is returning via the earth (possibly through the body of some unfortunate individual en route), and the RCD will disconnect all conductors (except, of course, the protective earth).

The same applies to a three-phase circuit, which may or may not have a neutral conductor, and (obvs.) single-phase, using just line and neutral.

Thanks, it works just the same as it does in Oz and the UK if i get you right. I cannot get my head around the system that is single phase 110v AND 220v. Other posters have said that it is often called 2 phase but they say that that is incorrect. I know a 3 phase RCD can also protect a single phase 240v outlet on one of the phases and neutral but i am not sure the US uses a neutral and apparently not even an earth! Which is the start of this thread. So what then?

edit Dumb question. of course the installation doesn't need an earth system for current to be lost to earth, a person will suffice. Then the RCD will trip.

Bang on.

Wikipedia has this diagram in the entry for split-phase electric power:

... tho' I don't know where it's used in Europe.

To my mind its wrong for most of Europe that I know of.

I believe generally in Europe, it looks more like a Wye (star) connected 3 phase secondary at the substation transformer.

Like this:-

The middle of the star is Neutral.

This neutral is also grounded.

I have not shown it as this may be done centrally at the substation transformer, or in each house separately.

But the Neutral and ground are fed on separate cables if done centrally.

Also plus 1 phase "hot end" (opposite to the star point) for UK domestic power and some other countries.

Or

Also plus 3 phase "hot ends" (opposite to the star point) for Germany and some other countries.

For US domestic power, it looks more like this I believe, that is the whole picture, not just a single phase:-

Though there could also be single phase transformers for each house, but it looks electrically the same as above.

I hope this helps.

In the UK, or certainly around this part of it, it is usual for one of the phases (R,Y or B) and neutral to be fed to each house in a street. It generally alternates along the street, so every third house would be e.g. R and N.

This can be witnessed if, e.g., a fault causes a fuse in one phase only to rupture at a local substation, plunging every third house into darkness.

Interesting!!

I remember when I put my first RCD in my 1450 AD house in the UK, many, many years ago.

Some months later, it tripped. It took me a long time to identify which house, one 3 doors away I do believe!!

It was the kettle, element holed...but I owned the only house with an RCD (or the equivalent then!!)......nobody else knew there was a problem....

My stepson "tested" the trip once too!!!

Other than that, no problems....

Most USA domestic power is like phases A and C, plus neutral, similar to your lower diagram w/ B omitted.

B would not be omitted, per se, it is simply not connected for domestic power, but its still there!

Nowadays, all 3 phases are always there, as often, simple 3 phase connection is needed for certain workshops and other businesses.

Don't read too much into the diagram that I borrowed....

That diagram shows what is delivered to say two houses for example, assuming for the moment that they share a phase.

Each house will get a single phase connection at 220VAC, A-C for example, plus the center tap for neutral and ground, which will provide 110VAC between phase and tap.

No houses will get a B-C or an A-B phase connection as shown as there is no center tap on those two phases.

But for a housing area, each of the three phases could have a center tap...The B-C and A-B for example in my drawing....

In reality, I bet they all transformers actually have the center tap, but its up to the planning if its actually used or not!!

But you are generally speaking "stuck" with 3 phases nowadays. Only a few historically old systems are still around that are different....

I hope this helps....

What are the grayed-in boxes in the upper diagram?

Fuse links. AKA fuses etc. In current practice, could be some other form of overcurrent protection.