A Question About 3-Phase Delta

First off, you have 3 phase at your house? If you are in North America (which I assume because you said 220V 3 phase), that would be HIGHLY unusual. 99.99999% of residential services are single phase.

How many poles did the breaker have? If it is really 3 phase, you would have a 3 pole circuit breaker.

Is there something else feeding power to the hot tub? Hint, there MUST be if the breaker is truly off and you are getting a 120V reading!

What are the other wire colors?

3 phase in a residence???

In most European countries it is not allowed to use electric motors above a certain capacity - 15 years ago it was limited to 1 HP -on single phase grids. So whatever spins there requires 3 phase. That is one of the reasons why the grid is way better and more balanced.

Red and white. The breaker is a double pole/2 wires and the third wire is connected to the neutral bar. I am guessing the black is the wire connected to the neutral bar. I have not looked at the actual breaker wiring unless I am convinced the breaker is bad. I have surmised the wiring from a wiring diagram that came with the new hot tub. That diagram had white connected to neutral not the black.

The reason I am posting this is I suspect something might be wrong. Since most of the breakers only have 1 pole /1 wire I am guessing the neutral bar is 120.

you're scaring me. if you're in the USA the white wire is typically run to your neutral and the black is "hot". if you have a true 240 you should read that across the breaker. taking a reading from one pole of the breaker to the neutral bar should give you 120V

Ordinarily red and black would be the two "hot" wires connected to the breaker; 240 volts to each other, and each of them 120 volts to neutral (white) and ground (green). If a neutral becomes accidentally disconnected, it is possible to have 120 volts on it.

I agree. This installation should be reviewed by somebody that already knows what they are doing. I doubt that this actually is a three phase Delta configuration. The two pole circuit breaker sounds much more like a single split phase power is provided to this hot tub. There must be a disconnect for each of the three phase "hot" leads for a safe disconnect. Now there might be a three phase delta motor with a pair of capacitors to simulate three phase power from this single split phase power. If there is I would consider replacing the electric motor with one that matches the available power.

If it is actually running single phase through a converter to a 3 phase motor, there should be a second breaker in the panel. Just a guess.

http://www.scribd.com/doc/58275129/How-to-connect-3phase-motor-to-single-phase

When in question, throw the main, disconnect everything, and hook up your new hot tub exactly the way it's supposed to be.

If you are measuring voltage after you have flipped the breaker off then something is definitely not right. First, you don't have three phase power if you only have double pole breaker. Second, you may have a separate feed for a water heater integral to the hot tub, and that's what you're reading. Third, you may have a poor ground and/or a poor connection between neutral and ground. Fourth, all circuits to a bathroom must be on a GFCI breaker, so it sounds like your wiring is outdated.

In any case, you're messing with lethal voltages in a wet environment with questionable wiring, as North of 60 said, get out of there and leave this one to the pros. The life you save may be your own.

North of 60 I would bet a month's pay the guy that wired it up WAS a licensed electrician. The project was completed years before I bought the house. The previous owner paid top dollar for the spa and the set up. The previous owner had much more money than sense. That electrician got the colors wrong not me. I can read a wiring diagram and I am not that sloppy. I was going to rewire the breaker correctly as soon as I figure out if the breaker should be replaced. I believe that everything should be right or at least with electric and plumbing.

I feel more than violated to have someone charge $100+/hr then screw up something I wouldn't screw up. In the area where I live the service industry rips off their customers more often than not. You being an honest guy would be appalled at some of the shenanigans I have seen. I have been told I had to rewire something that was wired perfectly well for only 2K. I told him to explain why the wiring needed to be changed in writing and the job was his. He ran out of the house cursing me. He was used to working for absolute morons. Nothing I have installed has had a problem because I triple check anything I am not familiar with. BTY this is my first electrical job in this house I am doing solo. In the past, I ran the wires then used to pay a licensed electrician to attach the wires. I bet a weeks pay my neutral was screwed up by one of those crooks. I have learned the only way you are sure to get a proper job is to know what should be done and see to it that it is done correctly. I am too suspicious to turn the job over to a stranger. If I don't think I can do the job 100% correctly, I will pay an electrician to do the job and take the day off to look over the guy's shoulder for every minute he is working. I will ask for explanations any time he does something I do not understand.

There is no wet environment. The last time the spa was filled was 15 yrs ago. By the way, I am alive. I was able to disconnect the wires and wire nut the wires without dying and without killing the power for the house. I am not even a bit proud.

Second, you may have a separate feed for a water heater integral to the hot tub, and that's what you're reading. No, I have looked at several wiring diagrams for several hot tubs and the wiring is basically the same for all. They all take 2 hots, a neutral and a ground. I would not be surprised if the ground and neutral were screwed up. I am only ignorant I am not stupid. Now that I know the neutral is not supposed to have a charge, I know that needs fixing.

The bathrooms and outdoor receptacles have GFCI protection at the receptacle. The hot tub will have a separate Spa Disconnect GFCI Load Center more than 5 ft from the spa. I purchased an NEC codebook last week so this project will be done by the book. I am a programmer by trade. We tend to be precise, logical and fairly smart. I like going by the book. It removes judgment from the equation.

If I do this job by myself I will likely hire someone to fix the neutral unless I discover the ground wire broke or something obvious. Otherwise after completing the first job he will fix the neutral. I will see if I can get him to check out the spa wiring if I completed the job myself. I can follow wire guides and codes but I lack the know how to trouble shoot something as complex as this.

A neighbor had to replace all his copper pipes due to electrolysis. I can assure you only electricians worked on the electricity in that house. That guy paid electricians to replace light fixtures.

I had to redo just about everything in my house that had previously been done by "professional" electricians. That was after having a "pro" come out and screw up something else.

Unless it's something that requires an expensive piece of equipment that I don't own, I do it myself. All plumbing, electrical, etc., is up to code and triple checked.

The internet is a wonderful thing; it saved me multiple trips to the library.

I'm sure it's something you can handle.

aDIYguy-

Please don't take offense about anything I am saying. I'm trying to help not antagonize. Also this is a long one.

Most hot tubs are 240 volts because of the motor. If it has any additional heaters that is another reason for the 240 volts. Having 2 poles on the circuit breaker indicates that it is a single phase 240 volt system (if your in the USA). 240 volt hot tubs are very often wired so that one thing, perhaps a pump, can be operated on 120 volts and another by 240 volts such as a heater. This would usually be wired with four wires: white- neutral; black- 120 volts between the white and this; a red- 120 volts between the this and the neutral (white) and 240 volts between this and the black one; and a green- ground for safety purposes. The black and red are often referred to as "hot legs" since they are electrified in reference to the white, neutral. If the system requires only 240 volts the white is not necessary and there will be only a red, a black and a green. These voltages, if taken at the hot tub when it is operating, are not necessarily what you will read with a VOM meter. If there is a broken or partially broken wire it will probably be indicated by a lower voltage. If the hot tub is not operating you should get these voltages listed above as your VOM readings.

A 3-phase system requires 3 poles on the circuit breaker. This appears not to be the case with your system. Since it only has 2 poles it will be a 240 volt single phase wiring. If it had only one pole it would be a 120 volt single phase. No offense to your friend intended.

It is difficult to determine why your wires are the colors they are without taking readings with a VOM while the unit is operating and not operating. If the voltages are low it is probably due to a bad wire or switch. The humidity associated with a hot tub tends to be harmful to the electrical components.

It is approved to use a wire of a different color for the required color only if the different color wire is taped on the outside with sufficient tape of the correct color to indicate its correct color for its application. This is done at each connection of the wire. Don't know why the installer made the changes he did. If you are going attempt to correct/replace the wiring use all conceivable caution while doing so. If the least bit of doubt comes up, stop and get better and more experienced minds involved. (For example- my father was a genius electrical eng. with a magna caum laude from MIT but I had to show him how to use the correct components to change the wiring in our house! No, it didn't get passed on to my generation)

Lastly, a copy of the National Electrical Code can be more dangerous than helpful. It is written for experienced licensed electricians and not the person with ordinary electrical experience. Even then many electricians can't read and understand it. There is a companion book out, either "Guide to the NEC 2013 or some other year" or "Understanding the NEC 2013 or any other year" or something like them. It is easiest to understand if the code book and the guide book are for the same year electrical code.

If at all possible get an electrician in to diagnose the old wiring situation. If he knows at the beginning that you only want a diagnosis and advice he will probably get you started. If not try someone else. In most states work can be done by either a licensed electrician or the home owner.

Just remember if you get hurt it is your fault, not mine. I am not liable for anything you do. The above are only a general guidance.

Good Luck, Old Salt

"...A neighbor had to replace all his copper pipes due to electrolysis. I can assure you only electricians worked on the electricity in that house...."

These two sentences don't go together, there is no cause and effect relationship between AC and electrolysis, if there were then the NEC wouldn't insist on bounding to the incoming water pipe. You should also know that electrolysis is caused by DC not AC. The most likely cause of his copper pipes leaking was galvanic corrosion caused by the water chemistry and mixing copper and galvanized piping and/or not using an insulating fitting on a hot water heater.

Glad to hear that you have a copy of the NEC, that will make you an electrician in the same fashion that reading Gray's Anatomy or the Merck Manual will make me a doctor, and possibly with the same results. Best of luck to you.

not enough of these

Track all the wires, often hot tubs will have more than one breaker. One for the pump, one for the lights, another for the heater, etc. Ring it all out, replace old breakers.

Find a diy book on electricity; three phase is three hots, and green for ground. Often there is no neutral white run, unless someone wants to draw single phase for a light or something, but that may not be code......Also, be extra careful with Delta, there will be a 220 leg on one of the wires, which will blow up anything you try to wire single phase with the white wire.....been there.....

Your neighbors may have lost copper if the electricians grounded stuff to the pipes, but neglected to ground the pipes to a ground rod. So many times the clamp at the ground rod comes loose, and then electrolysis and bad grounds happen.

There is so much wrong information on this thread I worry about your safety.

I wish you good luck. I have made my recommendations on how I think you should proceed.

I must Unsubscribe...

I though it was bad enough in the UK with the have a go brigade.

To my mind this guy deserves no help. He comes asking advice of professionals and then in one way or another calls us all con men.

Amen. Plus he gives a lot of wrong information to begin with. Half of Antwerp City is wired in 220/380 V 3 Phase. (most cook tops are 3 phases there)

His second post "forgets" the 3 phase. Makes him a bad programmer too, since he does not delete his false OP statement or doesn't correct it when possible.

I do not answer posts anymore, where the OP is Anonymous or doesn't give a rough idea which continent he posts from.

Maybe someone has already said so and I missed it, but if you need to ask this question, you really shouldn't be touching the equipment.

Do yourself and your family a favour and get a qualified person to do the work.

Funeral costs are going to be more than you will save trying to do it yourself.

I did not see (doesn't mean it's not here) where you actually took the cover off the mains box and looked at how the wires are connected there. I know, I know, that can be dangerous, but he says he may have to replace the breaker so he's planned on that possibility. Wiring diagrams only show how it should be connected, not how it is connected. IMHO.

I agree with just about everyone here that something is wrong and it could be dangerous.

Where you are not doing a good job with is that you do not tell us where you are on this planet, the infos you supply could fit several locations. Even giving the Hertz would help a bit!!! Why so secretive, it does not help your case.....it could even be downright dangerous and you appear NOT to understand that possibility.......

Furthermore, I think that your supply could possibly be simply missing the neutral/earth link, which can bring very high volts on the neutral in some cases. Local laws apply here so it is just about impossible to give valid infos safely in a blog. But this is a guess that I did not see from anyone else though - which could be good or even wrong!!

In my house, we have each phase (Germany, 3 phases to each house) protected by a RCD (or whatever they are called where you live), which when the power is unbalanced (going to earth instead of where it should be!), simply drops that phase(s) almost immediately..... a few milliseconds usually. It still hurts if it was your finger!!! Not if it was someone elses!!

The best advice is already there, learn what is needed and get a licensed person to do the job, just keep an eye on them....!! Simple.

And add RCDs.

Electricians I did not mean to impugn your reputation. I do not believe electricians differ from the general population in competence or honesty. I even responded to the implication I must have screwed up my breaker box by not using licensed electricians, that although you are competent and honest, not all licensed electricians are. Not admitting that there are some black sheep in your flock is very backward thinking. The problem we homeowners face trying to hire an electrician for a small job is the best have real jobs the good have big jobs leaving us the dregs. This is true for most skilled service. It is likely this problem is old. That means the last electrician to wire a 220 device should have known there was a problem and didn't say a thing. On the other hand not knowing the cause of my problem maybe it happened by itself in the last year or 2. The senerio "So many times the clamp at the ground rod comes loose, and then electrolysis and bad grounds happen." Sounds very plausible. I do not know where the ground rod is. If the neutral bar is supposed to be grounded like this and the clap is no longer functioning correctly no one is at fault.

Tom_Consulting
You are 100% correct. I indicated I had not looked at the wiring I was only guessing. I will this weekend. I am only guessing the black wire is wired to the neutral bar which is the most simple explaination. That is the least of my problems. If I keep it checking that breaker will be the last on the 2-do list.

Old Salt, I am rarely if ever, antagonized by facts. I do get incensed by undue condescension or intentional meanness. When you are as ignorant as myself in this field, modest condescension must be endured with grace because they are experts and I am trying to learn and am grateful to get this information and learn something. Groveling to your betters is expected throughout life. As a programmer, I had my years of groveling. For instance, I know my main breaker box is seriously screwed up. Had I left this to someone else I might not have learned of the problem.

Obviously, I do not have 3-phase in my house. Both the hot tub and the breaker box have easy to follow wiring diagrams. I would not attempt to touch anything if was the least bit unsure of what I was doing. As far as the wrong wire, I have already stated that needs to be corrected if indeed that is the problem. The misswiring is the most simple explanation for what I saw. If I do not correct the wiring the one that gets fooled 10 yrs from now might be me. I am happy to take the effort to make things right. The old spa wiring needs to be reviewed anyway. When programming I review all the effected code before I make changes.

Good advice on the NEC code book. It is not as clear as I had hoped. Fortunately, the breaker box came with a code cheat-sheet listing all the codes that apply to proper installation. My problem was more trying to locate the proper code than understanding the details. I am sure the manufacturer figures detailed documentation reduces the customer service load.

Thanks for all your advice. What I need to do for my spa is crystal clear. I think I need to trace the ground wires outside and find the bars and check the clamps. I can replace them if they look faulty. If that fixes everything maybe I will call it a day but probably I will have someone check what I have done. I don't need to pay an electrician to trace lines or replace clamps. I suspect knowing where they are will help me with negotiations. It should but me in a more favorable light with the electrician. I am sure the electricians have their own horror stories about idiot customers.

I just want to make a point. the color has no bearing on the ability of a wire to carry electricity. so a wire can be red, white, black, whatever and work just fine. the color coding system is merely a safety feature to aid in consistency. regardless of the wire color, or tracer color on the wire you still MUST check voltage and follow safety protocols. most of the time when I come across high voltage (like 220V) the color on both legs is the same(so both would be black or red, or whatever) when you mentioned one of the legs was red many here wondered if your application was Euro or US. and you are correct, having a licence or 50 years experience doesn't exclude you from making mistakes. but it does sound like unqualified hands played a role in some of your wiring hence the repeated calls for a pro to be consulted.

Let me make an emphasis here about why you should get a licensed electrician to get this hot tub up to today's code for electic power. People will be immersed in water that is driven and heated by lethal voltages. This can be done safely but this is not the type of project that a homeowner should try to learn about safe wiring.

Hire a licensed electrician.

The best course of action is to stop work and engage a local, qualified Electrician to complete it.

Thanks for all your help! You have altered my course of action.

After a chitchat with redfred off line, I want to clarify some things…

Again I do not think electricians are cooks or in competent. That is utter foolishness. I had a bad experience with one. Electricians who do odd jobs and are not semi-retired where I live probably have a problem. Even near worthless handymen I know have full time jobs and I wouldn't let either of them do any work on my house. I do not know if an actual electrician miss wired my breaker. By the caliber of the work, I expect a major contractor did the work. They would have a licensed electrician but that does not mean the electrician did do the final wiring maybe the supervisor wired it. Being an ex-supervisor I know how results oriented they need to be.

The wiring is not 3-phase. I have copious amounts of information how to set it up. The required GFCI breaker box marketed as designed for spas comes with more copious information including a list of code references specific to wiring a spa. I have a NEC codes for residential so I can read the codes. I will run the original 0 gage line into the GFCI breaker box since the lugs are big enough. The box has a pre-wired GFCI 60 AMP breaker and a 120V-15 AMP normal breaker. I will run 6-3 NM in a metal conduit from the box which must be at least 5 ft from the spa, to the spa. The spa end of the conduit will be sealed with duct seal as a moisture barrier just in case there is moisture in the electric box of the spa. The spa requires a 40 amp breaker so the wiring is oversized. I feel if I have been able to build stereos (the top of the Dynaco line pre-amp and power amp ) from kits I should be able to put the red, black, white and grounds in the proper locations.

I will surely wire everything except for the breaker and flipping the switch. I have done several projects and paid a licensed electrician to flip the switch. No errors were ever found in my work.

I will pull the face off the breaker box to see exactly how those wires are connected. I suspect I will want to hire a good electrician. After I know what is going on I will call one who is a friend unfortunately he does not live near by. He used to live in this area and can probably refer the right guy for the job.

Thanks old salt for the encouragement. I have a long way to go. The switch will not be flipped till Dec so I have plenty of time. I have been very successful because I do not take unnecessary risks (believe it or not). I also have a good handle on what I can do.

aDIYguy-

If it any consolation about your thoughts about electricians, I now use the best electrician I know, ME. When I was working I was the "go to guy" for more things that I was being paid for but I always thought that if I helped someone out I might repaid for the efforts. The most important thing I got out of it was helping someone out and not asking anything in return. It worked in many good ways for me besides the "thank you" I was usually given.

Now a little war story why I consider myself the best electrician I can afford (and I don't charge myself anything): In my life we have bought 2 new houses. The last one only had a few minor electrical problems. Most stemming from too long of wire runs from one CFI to the receptacles that ran off of it. No Problem. Changed wiring in GFI and installed GFI's to where the down line receptacles were. This work was originally done by a licensed electrician.

First new house was the biggest electrical mess that I had ever seen. Less than half of the ceiling light boxes worked, only two wall outlets worked, only one of the bathroom wall lights worked and both exterior outlets didn't work. In order for the wife to make toast she had to unplug the refrig and plug in the toaster in it's place. Unfortunately the pre-closing walk through wasn't at night! Also there were no bulbs in the sockets to test them. I was on a trip so wife did pre-closing tour. This again was done by a licensed electrician contracted by the builder! Made contractor get a different electrician to fix the problems. He reluctantly agreed. 3 days later all is fixed. Two weeks later I was installing a 50 amp outlet for a welder. Main Breaker panel was in garage so I located it one foot below the panel. Also television reception with antenna was very "jumpy".

While I had the panel cover off I noticed a slight yellow color behind the main breaker. Carefully used a plastic dentist's mirror and looked behind the main. To my surprise, the clamp on the main breaker was arcing between itself and one of the aluminum buss bars! Can't buy 150 amp breakers on Sunday afternoon so I relocated all the important circuits over to the good buss and left the others turned off. Monday it took 6 hours to find the correct breaker. Pulled the main breaker and sure enough the buss was pitted and the breaker was NG due to arcing. Gently filed down the buss to get rid of pitting and put copious quantity of antioxidant on the aluminum busses and the breaker clamps. Later I talked to three licensed electrician and described the condition before I fixed it. The third on got it right and an estimate of "at least $600" to fix it. Told him I already fixed the problem, bought him another beer and he was happy. The "jumpy" TV was due to this arcing.

Why did I go into this long detailed war story? Yes, some licensed electricians aren't worth the cost of a wire nut but some are worth more than what you pay them. Also some DIY's can do all the same as the good licensed guy but they must know what they are doing. One possibility is a self inflicted death. You must know not only what to do but also what not to do. I am glad to see that you have taken a less risky approach to this project. I'm still not liable for what you do but there are fewer risky things involved.

Now a short war story; In the next town 10 days ago a cable guy was working on an overhead cable wire. He touched the wrong wire. His funeral was 4 days ago. His family had to pay for the funeral.

Good Luck, Old Salt

Kramarat said:

"When in question, throw the main, disconnect everything, and hook up your new hot tub exactly the way it's supposed to be."

step 1. throw (open) the breaker believe to be the hot tub

2. measure every combination of wires going to it, none should be hot

3. if something is still hot, find the breaking feeding it. or is it the neutral thats hot?

4. if its the neutral thats hot, you should have a measurable voltage measuring neutral to ground.

5. dont let wire colors trick you, electricians will frequently wire with whatever color wire they have.

That's just what I would have done, since I'm not a professional electrician.

I'm not afraid to do electrical work, work in the panel, etc. I'm sure some of the pros would laugh at me, but unless it's replacing a simple switch or outlet, I shut off power at the main. I'd rather reset a few clocks, than die.

I've also found that even the "pros" get messed up, when coming into something that's been done wrong in the past.

Most of the time, rather than try to diagnose the screw up, it's easier to take the entire circuit apart and start from scratch.

Well Old Salt guessed correctly while my theory that the neutral was not neutral was way wrong.

There were 3 hots; two 220 and one 110. I originally discounted this because the 220 dual pole breaker controlled all noticeable functionality. On the way home from work it occurred to me the 110 may have been needed to power the ozonator which were rare when the spa was installed. When service men came out to service the spa while it was functional they all commented that the spa had an ozonator. Now, they are standard issue. Today, the wiring to spas has been standardised to 2 220 and one neutral.

Thanks for all your help. I have learned a good deal.

...and most importantly you lived to talk about it. As many on this forum will tell you, "The most important lessons are those that we learn after we know it all..."

aDIYguy-

Congratulations for your improvements in technical problem solving, consultation with others and perhaps the most difficult for most of us, working your way through a lot of diverse answers. As you noticed immediately, the repliers range from the best in their fields to the most arrogant, selfish, mean, deceitful, self serving, vicious, condescending idiots that were ever placed on this earth. Thankfully the vast majority are good and want to help each other. Often times the hardest part is separating the good from the BS. That's what you job is and only you can do it.

Please keep us up on how the project is going. Success to you!

Good Luck, Old Salt

I am not sure I like the way this comment reads. But that is OK... I will get over it. LOL...

I bailed out of this thread and said I had to unsubscribe... Why?

I am an "Authority Having Jurisdiction". When the OP clearly had no or little training in these matters, I had real concerns for his safety. I must always remember that I am an AHJ even when not on the clock. Advice given to anyone can be taken as official advice from a regulator, which exposes myself and my employer to possible liability, or so the legal beagles in our Dept of Justice tell me.

That is why I bailed... not because I did not want to offer help or advice to the OP (besides I knew others would step up to the plate).

Several others in my position, that I know of, have been dropped into precarious legal positions because of off hand advice given to persons untrained in these matters who promptly proceeded to hurt them selves and damage property.

Don't confuse valid reasons for not offering aid to such a posting for reasons that appear to be "arrogant, selfish, mean, deceitful, self serving, vicious, condescending" ones.

North of 60-

Sorry you may not agree with me. That's your perogative. As you can see from parts of my answers I never advised or was a proponent of the OP doing this work himself. My attempt and basis was that if he goes counter to this advise that he obtain further applicable knowledge concerning what he was getting into. For example these are excerpts from them:

Lastly, a copy of the National Electrical Code can be more dangerous than helpful. It is written for experienced licensed electricians and not the person with ordinary electrical experience. Even then many electricians can't read and understand it. There is a companion book out, either "Guide to the NEC 2013 or some other year" or "Understanding the NEC 2013 or any other year" or something like them. It is easiest to understand if the code book and the guide book are for the same year electrical code.

Just remember if you get hurt it is your fault, not mine. I am not liable for anything you do. The above are. only a general guidance.

As I stated before- Please don't take offense about anything I am saying. I'm trying to help, not antagonize. I would like to comment on your approach to your problem. Comments, not vicious, arrogant, questioning your quantity of brains or your mothers lineage. There are enough of those people around, I don't need to contribute to that type of answer.

Changing a faucet washer or piping in a sink is a far less dangerous thing than messing around with unknown or improperly installed wiring.

Why? An attempt to have you self-evaluate your skills and what the skills required for the job to be completed are. Its only my opinion, and opinions are like butt holes, every one has one, that you have a better chance of you staying alive than your present position is. This is my opinion. You don't have to believe it but to do so will lower the changes of your potential injuries or death.

Changing a faucet washer or piping in a sink is a far less dangerous thing than messing around with unknown or improperly installed wiring.

Now a short war story; In the next town 10 days ago a cable guy was working on an overhead cable wire. He touched the wrong wire. His funeral was 4 days ago. His family had to pay for the funeral.

Yes these have been taken out of the contest of the complete postings but also has the comment: Don't confuse valid reasons for not offering aid to such a posting for reasons that appear to be "arrogant, selfish, mean, deceitful, self serving, vicious, condescending" ones. The original text was:

As you noticed immediately, the repliers range from the best in their fields to the most arrogant, selfish, mean, deceitful, self serving, vicious, condescending idiots that were ever placed on this earth. Thankfully the vast majority are good and want to help each other. Often times the hardest part is separating the good from the BS. That's what you job is and only you can do it.

As most contributors to this thread know not everyone is the "Einstein" in the field of the original question. Some don't know their a$s from a hole in the ground about what they are talking about. Most contributors, yourself and myself hopefully, try to give the best answer we can . This is not true of everyone, thankfully only a few have the purpose of leading the OP astray and into difficulties. Also some take it beyond a technical reply to that of a vicious attack on the OP.

The OP decided not to follow the suggestions of many by progressing further with his attempts to correct this electrical problem. You bailed for your reasons, I stayed with my reason foremost to show the OP the dangers he could possibly get into but also to try to lessen the chances of death. I'm human and don't like to see people die, no matter what the reason.

I am not a "Authority Having Jurisdiction" which I surmise to be an electrical inspector. I'm an engineer with a h$ll of a lot of knowledge and experience with electrical despite that not being my original educational subject. Much of this knowledge came from the tradesmen who know what it is like in the trenches and have calluses on there hands and brains. What I do know is that there are many good to excellent electricians. There are also a few that don't know a wire-nut from a sweep elbow. I run from them but why do the good ones often use my knowledge as a resource? Also why are there some electrical inspectors who don't know what they are doing and don't have the faintest idea what to do? God bless the good ones!

With this forum I do not confuse valid reasons with the ones intended for destructive reasons. I try to avoid posting the bad ones and post the best I can. This is one area where I seldom become confused.

Good Luck, Old Salt

Thanks... your comments are well founded.

GA

Some good points on safety, a drum I bang from time to time as well, but few here ever give it a thought!!!

Safety was always paramount in my training, it was hammered into us time and time again.....

I am guessing but I believe you are in a 60Hz zone, probably in the USA.

Let someone correct me but I always thought that US homes had a single 220VAC phase, center tapped with a neutral/earth to allow 110VAC for domestic supplies, from either "hot" side to neutral and 220VAC single phase when used "hot" to "hot" between them for some domestic equipment....

Many (incorrectly) think its a 2 phase system.....that appears to be your thoughts as well if I follow your comments......

Do remember that there are no two phase systems, except when a 3 phase system loses a phase for some reason!!!!

The US System has two "hot" legs that are "in" phase/same phase, whereas two legs of a 3 phase system would be displaced by 120° (or 240° depending on how you measured it!).

I hopre this clears up the misunderstanding.

You describe it exactly as I understand the US system (except one point!) and as I described it in my last post. A very simple and easy to understand system.

I do not understand why so many fail to comprehend it fully...

But, you mentioned "Reversed" phase and measuring 0 volts. That is very misleading to anyone whose understanding is incomplete. Its also impossible to measure in practice!!

Even saying it in theory is wrong, though I could design a circuit USING 2 completely DIFFERENT PHASES, from two unlinked 3 phase sources that were 100% in phase with each other, but who would ever do that??????

For example, if you stay with a center tapped single 220VAC phase (as it really is!!) there is no possibility to measure 0 volts as it is simply impossible to do. (unless you go on the same point with both Voltmeter prods or forget to put at least one of them on anything!).

If we talk of 3 possible connection points, 2 x Hot legs and 1 central neutral (ignoring ground/earth for the moment as you mentioned "reversed phase"), putting the AC voltmeter prods on any 2 of the three connections will either measure 110VAC or 220VAC (or close to depending upon loads and cable lengths/thicknesses).

NEVER EVER 0 VOLTS......unless the fuses have been pulled!!!

Would you place two of YOUR fingers on any two 0 volt points that you talk about to prove that 0 volts is there? I think not!!! It might be the last thing you ever doon planet Earth!!!

Even measuring between neutral and ground, which should give a theoretical value of 0 volts, seldom does......many do not understand that too....

But ANY measurement involving either of the Hot legs and the neutral will not and cannot give 0 volts in a properly connected and live system!!!

Even talking in your manner demonstrates that even you do not understand the US system 100%.....say 95% at best.

Sorry to have to say it.....

Impossible to measure the two busses 180 degrees out of phase with from each other?

Yikes, I though German engineering was miles (kilometres) ahead of the US.

Guess I was wrong.

Not impossible, just not easy and still a total waste of time....I have never heard of anyone ever needing to do it, but you might/can be the first if you wish!!

The only important requirement (someone else has already mentioned it here) is the direction of rotation......there are plenty of simple methods to measure this....

You are just repeating (except for slight voltage value change, which is, by the way, VERY variable in the USA due to loads, load balancing errors and distance to the transformer/substation/generator) the same as I both understand and wrote.

Here for example have according to the standards 240VAC. I have never ever measured 240VAC in any European countries......

I do believe you did not take the time to study any of my posts fully. Sorry, but speed reading has a lot of negative aspects. Which is why I myself always read such infos at least twice before replying,,,,

My intention was to explain to certain people on CR that live in the USA that they do not have 2 phases coming into their house.....only 1.

MANY DO NOT UNDERSTAND THIS....STILL! It is important.

You're absolutely correct Andy. I believe a major part of the confusion comes from our wiring information found in a split phase circuit breaker panel. Each HOT line is frequently identified as just "PHASE". Since there are two of these, many incorrectly leap to the conclusion that this is two phase power.

You are fully correct!!! Thanks.

In 1895, electricity was in its infancy.

Therefore 2 phase power has as good as nothing to do with modern installations. I thought it best not to confuse the people here anymore than needed.

You think differently to me. No problem there.

By the way, I am a big fan of Wiki, I always post the link, you should too.

Here it is for any interested people:-

http://en.wikipedia.org/wiki/2_phase_power

The article is very short, but seems to adequately describe the pros and cons of such a system and why it has all but died out in most places around the world.

I would expect that equipment built to the standard is either nowadays very old (but still useable) or expensive or both, though I have not researched that myself....

Power wise it is wasteful and for that reason alone is unlikely to suffer a "comeback" to my mind! Also, correct cabling uses more copper than modern methods need in relationship to power used.

The last but very enduring remnant of true two phase and not split phase power usage is two phase stepping motors and their drivers. I realize that this is not a power distribution use of two phase power but the 90° current relationship while the motor moves in a fairly uniform manner.

Allow me to correct you.

110/220?

You thought too much. Try 120/240 RMS (closer to 118 in most areas)...all day long. Check NEC 310.15(B)(7) if you don't believe me (just one example in the NEC). There, I even gave an easy reference for lazy readers! Ain't I so nice?

Niagara Falls Power House Number 1 was true two-phase. Some military and industrial complexes still use true two phase.

Two-phase system

There are more examples, so explaining the difference between two-phase and split-phase with applicable references might be better than providing other "facts" that are, in fact, not factual.

The two legs of a split-phase system are not "in phase" but two separate portions of the same cycle which appear 180 degrees out of phase with reference to the neutral point, hence split phase. If there were no phase separation, however, through the center tapped reference, then we would not have a resultant 240VAC, just two 120VAC waveforms in-phase.

Cheers!

Not necessarily, depends upon local code. In the Canadian code, the neutral must be sized at least as large as the maximum single phase load that either of the line to neutral pairs will see.

For example, on a 200 amp service, assuming that L1 is the highest loaded line and the connected load is 180 amps and 50 amps of that load comes from loads across the L1 to L2 pair (220 volt loads), the neutral must be sized to handle a minimum of 130 amps.

I am pretty sure the NEC is the same in that regard.

This comes into play a lot with three-phase, triplen harmonics and all that.

I oversize my neutrals on installs to prevent overheating (all those stupid single phase SMPS's).

Agreed...

The recent trend to oversize neutrals in large non-linear load installations appears to be starting to go the other way again.

I have recently read a very concise study on the issue done by UL on the neutral currents (over several of the fundamentals of the base frequency) in large non-linear load environments. Going from memory, it is the third fundamental that sees the highest impact from non-linear loads these days. And the impact is decreasing... or so the study showed. I will try and find a URL for those interested in reading more.

A lot of the newer SMPS's and UPS's available in equipment on the commercial market have built in harmonic reducing filters, useful for PF correction, eliminating the impact before reaching the panel.

We just had a new data center installed. The servers and the workstations from IBM and Dell had this as a feature. It was just a one line item in the documentation, not touted as a great new thing, but I was happy to see it*.

*You know that feeling when you geek out over some new technological engineering feat, and you look at the blank faces around you, and you know they are thinking you need to get a life? Yeah, that's how I felt.

As it turns out... I know your rep to the CEC Part I Technical Committee as I sit on that committee... LOL and to many other techincal committees to mention.

Funny... I am at CEC code meetings at this moment.

Sorry... but, this statement is wrong, or it appears to be wrong as I may be mis-reading what you meant to say (I hope so).

You said...

The two legs of a split-phase system are not "in phase" but two separate portions of the same cycle which appear 180 degrees out of phase with reference to the neutral point, hence split phase. If there were no phase separation, however, through the center tapped reference, then we would not have a resultant 240VAC, just two 120VAC waveforms in-phase.

Of course they would measure 240 volts. Why? The standard 120/240 volt split phase transformer used in North America... can be considered as two 120 volt sources in series or as one 240 volt source. That is why, return current from 240 volt loads do not return on the neutral.

Transformers have polarity markings on their magnetic cores! Why? To ensure that the flux interactions with the windings and therefore the impressed voltage on those windings are either in phase or not and so that the resulting sources are either additive or subtractive. This is the basic concept behind the "buck" and the "boost" transformer winding configurations.

If the L1 to the neutral pair was 180 deg out of phase to the L2 to Neutral pair... we would measure 0 volts between L1 to L2.

Would you care to elaborate on your comment?

I understand both of you and also how a transformer is wound. The pot types just have no split {and separate(d)} secundaries and only 3 connection points. The ones I have seen looked more like blacksmith constructions (flat band copper).

I guess our friend was speaking hypothetically and it is good and correct that you pointed this out.

I think we are describing the same thing two different ways.

I don't know what a "neutral pair" is, though.

In this instance, we either use L1-Neutral, L2-Neutral, or L1-L2. Those are three pairs. Is that what you are referring to?

Anyway...

There are zero Volts AC between the two phases...60 times per second. The other 60 times per second (for the full wave of 60 cycle power) they are 180 degrees out of phase producing 240VAC.

I even put some dots on there for polarity.

Please do me a small favor... please go read...

Click Here

Then if you still want to discuss... let me know.

Agreed... when one uses the center point on the transformer as a reference point, it does appear as if there is a phase shift of 180 deg between the two sources. No argument there.

Having said that... the appearance of a phase shift does not in fact mean there is a an actual phase shift present. The laws of physics dictate that two sources, of equal potential, 180 deg apart connected in series sum to 0. There is no way around that.

The phase angles cannot be ignored. Take a 120/208 Y system as an example. We get 208 volts and not 240 volts across two legs of the three phase system because of the phase difference between the impressed voltage in the windings of the two secondary coils of the transformer. Because the voltage levels in these coils at any given point in time are different.

I also agree that "how" you look at the nature of our split phase 120/240 volt residential service in North America can flavor a persons's view on this issue. But... again, how you look at a given system is not truly descriptive of that system.

For example... scoping this system using a dual channel scope with the reference on the neutral and the two probe channels on L1 & L2 will create the trace shown above. This is a distorted picture of the relationships present.

I am also constantly surprised to see how many trained electrical people do not grasp this issue. The laws of physics cannot be ignored.

GA. You appear to be the only one here FULLY trained and FULLY knowledgeable.

You wrote:-

I am also constantly surprised to see how many trained electrical people do not grasp this issue. The laws of physics cannot be ignored.

A lot of them appear to be on CR4!! I have even met EEs that STILL did not understand it. THEY WILL NEVER EVER FULLY UNDERSTAND THIS.....

My party trick is to ask them which points on my mains fuebox they are willing to touch and which they won't (I do have RCDs at home on all three phases....)

They do not have a clue what is safe and what is not!!! THEY WILL NOT TOUCH ANYTHING!

It reminds me a bit of this really old video:-

http://www.youtube.com/watch?v=NaEfU47QY_k

Agreed... when one uses the center point on the transformer as a reference point, it doesappear as if there is a phase shift of 180 deg between the two sources. No argument there.

This and nothing else is part of the discussion.

Thank you. Spread the word.

I guess lot of electricians in the US and Canada, if not all will measure between the neutral and one leg.In my words: you (and every one) are using the neutral as the reference point, no?

You guys have been sitting just with your noses in your own power system withoutunderstanding noticing this detail. I agree, it is such a natural thing, and you are so used to it that you don't think about it. Probably no one teaches you this either. You just take your conventional or digital voltmeter and always measure 120 Volts.

It is actually good that the transformer manufacturer leaves you no choice of playing with the (common) terminals of the 2 half coils of the secondary.

An oscilloscope is a "viewer" for what a digital meter falls short off. The tinkerers diagram is what you see when you trigger e.g. one channel on a rising start.

I suggest if you want to start a discussion about 3 phase, to make a new topic, because it has nothing to do with our issue of a split phase 120/240 Volts net.
Three years ago we had the same discussion. I just feel sorry that in these years you guys still didn't see the light on this topic.

However we still are all Conference Roomers. The houses will still have 120/240 and who cares if L1 and L2 has 180 degrees phase shift?
Do not take this personal: it is for all the G.A. voters in this sub post. Glasses and a candle don't help if the (in)sight is missing.

I do not follow what you are getting at. Anyways, we have talked this issue to death.

I'm not dead, yet.

Really good, hopefully he will understand it better through this link!!!

I can't believe this is still under discussion...

Just returned from turkey day holiday and read on...

I think you missed my snarky comment that yes, there will be 0VAC, 60 times per second. The other 60 times per second with two waveforms 180 degrees out of phase will produce the 240VAC. Your diagrams are not relative to the question at hand...OT.

Regardless of how anybody else looks at it, regardless of how you want to look at it, regardless of how anybody is taught and regardless of any other point...facts dictate truth. I don't care what single piece of test equipment you want to throw out there into the ring...you can nudge the facts and try to confuse people who are trying to comprehend your rhetoric.

Any electrical engineer, electrician, electronics technician, or whatever worth their salt should understand that the theories of electricity can be calculated applied in a myriad of ways.

I won't reply to Andy, he's a proven imbecile.

I fully understand the diagram, it is correct but it due to the way the scope is attached, it will seriously mislead some people......

You can only see that trace on a scope that has one channel connected between neutral and L1 and the other between neutral and L2. With the ground on each scope probe connected to the neutral.....if one was reversed, the phases would track exactly one on the other....

DANGER. Do not reverse the connections to any scope as you need to make a change to the scope grounding to prevent a neutral/earth to phase short and know how to handle the scope in such situations....a shock may otherwise happen.

With a standard scope, you cannot safely show that across L1-L2 is a single phase at 230(?)VAC or close to......In Europe I can as one side of the mains is neutral.....connect that to the scope probe ground....

This point alone shows correctly that although the US system has a far lower voltage to neutral (thought to be safer though the frequency is also different), the actual safety with regard to certain test equipment is far less, unless you REALLY know what to do.

This diagram is partially the reason why some people think that they have two (separate) phases coming into the house.....when they don't!!

Hi Andy,

I fully understand the diagram, it is correct but it due to the way the scope is attached, it will seriously mislead some people......

every electrician here measures between the neutral and one leg - WHO misleads?

You can only see that trace on a scope that has one channel connected between neutral and L1 and the other between neutral and L2. With the ground on each scope probe connected to the neutral.....if one was reversed, the phases would track exactly one on the other....

unless you use a scope from just after WW2, the inputs can be complete galvanic separated and if not, for this measurement you can always use safety transformer. The probes are better insulated types, used for grid voltages

DANGER. Do not reverse the connections to any scope as you need to make a change to the scope grounding to prevent a neutral/earth to phase short and know how to handle the scope in such situations....a shock may otherwise happen.

floating inputs - ever heard of it It is the same as if measure with 2 single channel scopes - know your stuff - the risk that you describe can occur with the wrong material or practices. Each double beam oscilloscope with isolated input can handle all switches when both channels have the "reference" of each probe (what can be refererred to as mass) together connected. Here to the neutral.

With a standard scope, you cannot safely show that across L1-L2 is a single phase at 230(?)VAC or close to......In Europe I can as one side of the mains is neutral.....connect that to the scope probe ground....

They come even with battery, like any digital multimeter - the scope I use has 100 Mohms between the "floating grounds.

This point alone shows correctly that although the US system has a far lower voltage to neutral (thought to be safer though the frequency is also different), the actual safety with regard to certain test equipment is far less, unless you REALLY know what to do.

This diagram is partially the reason why some people think that they have two (separate) phases coming into the house.....when they don't!!

Let us agree that we call it single phase split to not confuse more.

These are just some comments that some people may learn from.

Oh beetle's knuckles. There are several battery driven oscilloscopes available today. For those who have a grounded two channel oscilloscope, just subtract channel one from channel two in the oscilloscope while measuring two signals. Viola, the difference between the two will be displayed.

Now let this zombie sleep in peace.

You are simply unthinking and very dangerous, we are discussing mains voltages here!!!

There are still plenty of old scopes around that could prove unsafe in the hands of a layman.

Even old scope probes that the insulation may not be now as good as it should be.

Even a good modern scope used wrongly could still be dangerous....

I wrote that post to try and take that into account.

Safety should always be a first priority.

Having taught electrical safety to many engineers over the years, that is ingrained in my soul. Anyone who really knows me here on CR4 knows that about me....

You have opened a can of dangerous worms as you did not tell the amateurs here how to differentiate between scopes that can handle this and ones that cannot.

Neither did I, but I wrote it to try and keep everyone as safe as possible....

You missed that point by a mile or two.......

Try thinking before writing.

That you are rude to me is unimportant, I simply ignore rudeness, but breaking safety rules is unforgivable.

If you can not shoot don't use a gun.

If you do not know how to use a oscilloscope don't use one.

Read the (F) manual. RTFM, goes for everything.

This is not the issue. I went off topic because I wanted to help you, but a off topic on an off topic, I don't start.

BTW: A US cope, powered from the net works on 120 Volts. Nothing wrong to connect the input Low to the neutral, that is (close to the) ground potential.

If L1 and L2 are in phase, you guys will connect them together? NOT ME, sorry - THAT is dangerous. Please Andy start teaching safe things to electricians yourself. I have read posts of you on how to synchronize generators in parallel that were brilliant and here with a simple system you go completely the wrong way. It is not my task to examine you but here you fail. When I fail, I am not too proud to admit it. I went wrong too in my life. And once you meet a clever electrician your credibility will be endangered.

Perhaps stay with multiple phase systems, until you get to know how a split single phase system works. It is probably too simple for geniuses. But don't feel too bad. You are not alone: I visit plenty of different forums and a lot of US and Canadian electricians perfectly understand that the phase shift in multiple electrical systems is 360 degrees divided by the number of phases. 3 Phase = 360/3 >120 degrees, 4, 5, 6 and more, do the math.

(perhaps a split phase might be also a 2 phase system (Phase shift 360/2 = 180 degrees -what it is // for me, theoretically when referred to the neutral the split phase is more a 2 phase system than the earlier produced 2 phase system with a running field - in this context the split phase does not produce one. Transformers with center tap are known to produce 2 split phases)

I try to keep my feet on the ground, and when I want to fly, I count my money to take an airplane. No offense meant. D.

I went a few pages back in this blog, but I was unable to find anything I wrote that appears to fit with whatever got under your skin that you made BOLD in your last post!

Perhaps you would be so kind as to let me know which posts of min they are. Thanks in advance. If I agree with you then, I will retract.

By the way, safe posting is not the same as teaching, so don't get mixed up with the two?

Safe posting is for example not telling anyone to do something (you don't have a clue who is reading and their knowledge and abilities for example) that could be dangerous, without at least a warning. You obviously do not agree with this.

Teaching is explaining exactly why it should not be done.

I can do either at will, maybe that's why you got a little mixed up, sorry if I accidentally mislead you.....but you are easily mislead maybe?

N of 60, another GA from me for picking up on the same c**p as I did.

Well done. You know your subject well (a big change on CR4!!)

Thank you Sir...

You said exactly the same as I wrote! Good to know that we agree!!

Congratulations, well done m8!