# 3 Phase Wiring?



## Lookin4GoodLife (Oct 14, 2013)

I've been told the house I live in has 3 phase wiring. Is that a good thing or a bad thing? Most of the house is still on screw in fuses and I hope to get one large panel installed at some point. Should we stay with the 3 phase or change it over to "regular"? How do I check to find out if it is indeed 3 phase?

Also, the previous owner had a fountain and a light at a remote location in the yard. The feeder wire was overhead and then run down a utility pole in the corner of the yard. At some point, the feature was removed and the wire was just left buried under the ground. I was going to dig the wire up and mount a weather proof outlet box on the utility pole. When I started looking at the wire, it's UF 14/3 wire. There's a neutral wire and two hot wires. It's kind of in a jumble where it feeds from the side of the house, so I can't really see how it's connected. Most of the wiring in my house upstairs is two prong outlets with no ground. I'll replace all that later, but for now, I'd like to get this outside outlet set up. Is there any way to get the proper feed to this outlet short of rerunning the whole thing? I'll get an electrician out here if I have to, but I kinda wanted to know what I was looking at before I went that route. Thanks.


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## Xperthunter (Mar 30, 2015)

Okay first and Foremost - I AM NOT AN ELECTRICIAN; Just a guy that deals w/ stuffs of this sort. 

With that disclaimer; 


Part 1: First determine if you have a 3 phase system. To do this, use your multmeter where your main line comes in from the pole to some mains box in your house. Determine if you have a 3 wire or a 4 wire system. That is to say that some 3 phase systems have 3 wires, where one wire acts as "hot" and the other 2 togather act as "return". In a 3 phase system the sum of all 3 phases is null. The other way you may find is a 4 wire system. In this you would see 3 "hot" and a seperate Neutral. Remember that the neutral in a single phase, or 3 phase 4 wire system from the transformer will be grounded both at the house and at the transformer if done "right". Your neutral thus acts as a bonded ground. You get your voltage then with 2 wires as hot and neutral as your return. 

Note 0: How you test, From your mains pannel you will put your Multimeter on AC and amperage > 200; Assuming you have a 4 wire system, you will have a neutral (Should be obvious) and 3 phased wires. From any of the 3 wires (call em A, B, C, and Neutral N); A to B = 240ish Volts, A to C = 240ish Volts, B to C = 240ish Volts; And then from each phase to Neutral, you will have 120V; 

Part 2: Upgrading/Changing your system to a standard single phase AC normally involves a change of transformer, change of cables (heavier duty, larger diameter), and your new box. 

Note 1: 3 phase is actually pretty common in all of Europe, and in nearly every electric motor (Think your 3 phase dryer, where you have 2 live wires and a neutral); 

Part 3: For your outdoor bit, I'ed put a multi-meter to it and see what you have. From what your describing you have 3 phase going to it, you could consider a LED light, in which case a rectifier diode will make your 3 phases into a single DC output and you can run a very efficient LED system. 

Sorry this is a mess to follow, writing at work and between calls.


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## Harry Chickpea (Dec 19, 2008)

"When I started looking at the wire, it's UF 14/3 wire. There's a neutral wire and two hot wires."

I doubt that you have three phase. You have described standard split single phase wiring. Call the power company. Their records will show what you have.


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## TnAndy (Sep 15, 2005)

Be* very* unusual for you to have 3 phase in a house. Unless there are some large motors, (like in a home shop, or farm use) the power company wouldn't even consider putting it in. And you would be paying commercial rates.

Quick "look" test:

1. Look at your main panel. Do you 3 columns of breakers (or fuses) ? (3 phase) 

Or do you see two columns of breakers (Single phase)


OR:

2. Go outside and look at the wiring from your transformer. 

Are there 3 transformers with 3 insulated wires + one bare ? (3 phase). 

Or do you have a single transformer with 2 wires + bare wire ? (Single phase)


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## Lookin4GoodLife (Oct 14, 2013)

Here are some pics for clarity..... based on what you guys are saying, I think I indeed have 3 phase wiring. This house was built in 1946 and at the time it was built, it was an "executive" home in our little town. I don't know why Mr. Jabaley would have had 3 phase put in, but who knows?  The first picture shows the wiring going into our house next door to our house in question. It shows two wires going into the house. The second picture shows the utility pole in the corner of our yard that feeds both our houses and the neighbor's house. It's hard to see in the picture, but in the top right, you can see the two wires and support cable that goes to our house next door. In the lower left, you can see the two wires and the support cable that goes to the neighbor's house. In the middle left, it's hard to see, but there are three wires and a support cable going to our house in question. In the third picture, you can see the transformers out on the street. There are two wires coming off one transformer and one wire coming off the smaller transformer, that leads over to the utility pole in the yard. The next picture shows where it comes into our house. There is the support wire, then what looks like a bare ground strap and then three black wires that enter the house. The next two pictures shows the mess that's in our basement. The breaker panel on the lower right was added later at some point and mostly feeds our HVAC and the mother-in-law suite downstairs with full kitchen. I guess it also feeds the washer and dryer downstairs. The two fuse boxes on the right are not used I don't think. One actually has tape on it that says "not in use" and the other doesn't have any fuses screwed into it. But the wiring passes through it into the breaker panel, so they were probably removed at that time. The big honker with the 3 fuses in it is the main. So by what you're saying Andy, I guess with the three wires outside with the one bare and the 3 fuses in the main fuse box, it is indeed 3 phase? 

I remember when I was a kid, Mr. Jabaley, the man who built this house, owned a men's clothing store in a nearby town. He use to buy cars to tinker with and then sell them later as a hobby. Maybe he had a welder, but I don't remember seeing him do anything but crawl under the hood, but maybe he built it with the idea of building a shop out back or something? I dunno. Anyway....  I appreciate everyone's input!


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## Lookin4GoodLife (Oct 14, 2013)

Oh and I've never thought to examine the bill for any "commercial" rating..... I'll pull them out if I get a chance and see if there's any different coding for this house and the house next door.


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## Lookin4GoodLife (Oct 14, 2013)

And btw, that rat's nest under where the wiring comes into our house is the UF feed over to the utility pole where the fountain and light were. Can you believe they just left that wiring with wire nuts on the outside of the house?! Sheesh. I'll post some pics later of that setup and maybe we can decipher that one.


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## TnAndy (Sep 15, 2005)

Yep....you do have 3 phase. The first pic is a single phase service, the other one is a 3 phase service. The fused disconnect you show has 3 fuses, also an indication of 3 phase, each leg fused. The transformer setup is odd....seems they are taking 2 phases off the large transformer and the 3rd phase off the smaller one. Not how it's done here, but apparently works.

Now I'd wonder WHY someone did that in a home ? Did they have a woodworking shop or something along that line in the basement ? Lot of times larger motors (5hp and up) are 3 phase because the motors are much cheaper. Generally, that is the only reason to go 3ph. The smaller disconnect with the "X" on the lid, for example, is a 3ph disconnect that feeds (or did feed) something.....probably a motor driven something.

I couldn't get 3ph if I wanted it here....we only have a single phase line coming up our road off the 3ph line down in the valley. It would cost a fortune to get it up here, and I'd have to agree to buy some large minimum amount of power before they would even consider it even if I was right UNDER the 3ph line.

Yeah, I'd make sure I wasn't paying commercial rates (which are usually 25% or more higher) for your power.

Certainly an odd set up for a home. The wall setup was pretty well done for it's age (probably late 40's-late 50's), the feed to the fountain on the outside is clearly much later, and a cobbled up job the original electrician would have never done.


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## Lookin4GoodLife (Oct 14, 2013)

I can't imagine what he would have used it for. I came in this house many times as a boy, but wouldn't have know what to look for and I don't remember anything "unusual". The only thing I could figure is at the time he wanted "the best" and that's what the electrician talked him or the architect into.  The only thing I ever knew him to do for a living was the clothing store and later, he and his brother owned a liquor store. He tinkered with cars, but didn't have any kind of professional shop out back or anything. Come to think of it, another brother or maybe it was his cousin..... hunh.... maybe Rocky's his nephew..... ANYway, he still owns an appliance store in this town. Maybe it was his recommendation that John install it "just in case" for something down the road. You know how things get stuck in people's mind when they're building a house and start taking people's "advice".


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## Lookin4GoodLife (Oct 14, 2013)

Only other thing I could think of was if he had some kind of industrial strength furnace installed. There's a pipe outside the house with a metal cap on it that goes underground. I was told that was where they filled the oil tank for the furnace. (The house next door has a coal chute on the side of the house.) Maybe the furnace had some great big ol' blower on it that would have required the 3 phase? I can't imagine needing that unless the heaters "back in the day" were really inefficient because the upstairs is only about 1600 sq ft. Even if they were heating the basement, that'd be a pretty serious blower.....


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## sammyd (Mar 11, 2007)

> . Look at your main panel. Do you 3 columns of breakers (or fuses) ? (3 phase)


 I've been working with 3 phase a long time and have never seen a box with 3 columns of breakers. The buss bars are shaped to make 2 columns of breakers.


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## Jlynnp (Sep 9, 2014)

I showed all of this to my DH who is retired from 32 yrs working for the utility co and he say yes it is 3 phase but goes on to say you may not be using all 3 phases. He also said he would get someone in to clean that mess up, install a new breaker box and properly label the thing so you know what is what.


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## TnAndy (Sep 15, 2005)

sammyd said:


> I've been working with 3 phase a long time and have never seen a box with 3 columns of breakers. The buss bars are shaped to make 2 columns of breakers.




You're correct. I should have said 3 points of connection for the main breaker.


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## Lookin4GoodLife (Oct 14, 2013)

Jlynnp said:


> I showed all of this to my DH who is retired from 32 yrs working for the utility co and he say yes it is 3 phase but goes on to say you may not be using all 3 phases. He also said he would get someone in to clean that mess up, install a new breaker box and properly label the thing so you know what is what.


That is the plan, but something always seems to be eating my money supply!


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## Swagner (Feb 7, 2015)

As an electrical contractor 3 phase in residential is unheard of around me. But it is truly the most efficient power source. I might also add that typically when you have three phase it isn't 240/120 it's actually 208/120 so keep that in mind when you get appliances. You may need to buy commercial rated dryers and stoves for them to run most efficient.


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## Lookin4GoodLife (Oct 14, 2013)

Hunh.... Looking at my last month's bill, I'm actually paying *less* for the 3 phase. That meter is a lot bigger than the one on the other house and it actually says "4 wire 3 phase" on it. On my bill, there's a meter multiplier of 10, that's the only difference I can see in the bills. But the bill for the 3 phase house is .09909 cents per kWh and the 2 phase house is .10587 cents per kWh. Would be interesting to look into it further, but I'm not one to go swatting at a hornet's nest with a stick just because it's there.


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## Lookin4GoodLife (Oct 14, 2013)

Ok, so the $10,000 question is..... should I take it out? I'd like to get a quote from an electrician to take all this stuff out and replace it with a breaker panel. Is it as simple as the city doing their deal with the transformer and replacing the meter with a 2 phase meter and the electrician replacing all the fuse boxes with a panel? And should I add the existing breaker panel into the new panel or just leave it as a sub-panel? My dryer downstairs is coming off the panel, but I haven't measured the voltage. It's just a standard old dryer, though, so I don't think it's anything special. The stove and range top upstairs are the originals.... Amana or Frigidare, can't remember which, but they may be special, I don't know. We have a standard GE stove downstairs, but it's running off the breaker panel also. I can check that outlet if I need to, but that stove's been there quite a while with no problems as far as I know. Maybe I should ask my neighbor's Dad, he's an electrician here, but I think he's commercial. He'd probably know though. I just want to give that aforementioned hornet's nest a wide berth if I can.


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## mreynolds (Jan 1, 2015)

I would think if it is working out fine for you and the bill is cheaper then leave it three phase. Just have your electrician change out with a three phase box. If you decide to go with single phase then all the electric company has to do is take one wire away and hopefully clean up that mess

Either way you go you electrician would take care of that for you. It really should be his call anyway on what is recommended for your personal situation. You have the right idea that you need to do something. Calling your electrician should be the next step.

All the best going forward.


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## farminghandyman (Mar 4, 2005)

Swagner said:


> As an electrical contractor 3 phase in residential is unheard of around me. But it is truly the most efficient power source. I might also add that typically when you have three phase it isn't 240/120 it's actually 208/120 so keep that in mind when you get appliances. You may need to buy commercial rated dryers and stoves for them to run most efficient.


 delta three phase is 240/120, and is used a lot where single phase is the main need and three phase loads are minimal, you end up with a wild leg of 208 (to neutral/ground)
on some installations it is a two transformer called open delta three phase, 

this is what I have on my farm.


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## Lookin4GoodLife (Oct 14, 2013)

I'll call the electrician next week and see if I can get him out here. Thanks for everyone's input!


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## Sawmill Jim (Dec 5, 2008)

Lookin4GoodLife said:


> I'll call the electrician next week and see if I can get him out here. Thanks for everyone's input!


I bet a 3 ph heat and air unit running on 3ph would be so cheep you would think you were stealing electric .


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## Lookin4GoodLife (Oct 14, 2013)

Something to consider. I think our unit is 16 or 17 years old, so maybe we need to price out the two. Thanks Jim!


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## Ozarka (Apr 15, 2007)

This is unique in my 45+ years of blessing wires...to find a 3 phase service on a residence. The Open Delta bank is a common small industrial shop use, you don't need the third transformer unless your load is more than 10-5 kVA. Your equipment cost for new would be astronomical, get a single phase service installed and buy normal residential stuff. 3 Phase is totally unnecessary in residential applications.


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