Terrible error

Dave Belisle

I understand your anger and frustration , but it sounds like there is more blame to go around than just the power company. Did I read right it took three years to find the problem ??? When any electrian worth his salt energizes a service he will check all the voltages phase to phase and to the neutral and ground before he turns the power on.

Some of the older power systems have a high leg for the third phase. They use single phase to generate the third leg.

The third leg is generated at the transformer and is 90 degrees out of phase of your other two legs. So if you read from the first two legs you will read 120 volts to ground. But if you read the high leg to ground you will read almost 200 volts. Any two of the three legs will read 240 volts

True Three phase on the other hand is three seperate lines 120 degress out of phase with each other. If you read from phase to ground you will get 120 volts on each leg but from phase to phase you will read 208 volts.

Granted , I wouldn't be happy with the power company , but check your service . You may only be using single phase but your main disconnect might be Three Phase , it will say on the cover of the disconnect what it is. If it is three phase the center line should be marked with Orange tape to tell the electrician it is a high leg and can only be used for three phase equipment , No single phase !!!
( although I have used that high leg for 240 volt pumps )

High legs are in older power systems and you don't see them installed today . Not every electrician has seen a high leg.

Make sure your trades people did everything right or the only ones that will come out of this happy will be the lawyers.

Good luck

Dave

Mike T., Swampeast MO

This one's going to court...

Building that houses the store and bar where I'm a partner had a fire 3 years ago. Solid triple-wythe brick--old "downtown" type construction.

Fire started in a semi-attached frame lean-to storage area and spread via unsealed penetrations for power and A/C lines. Everything renovated before I was involved and completely inspected. As is normal, power to the building was literally cut at the nearest utility pole.

Have had CRAZY power problems ever since. Coolers and A/C units the worst. MANY compressor replacements--some with multiple replacements in the same unit. Some incandescent lights burn out very quickly. Some fans seemed unusually loud since day one. Ballasts for the outside sign (high-output fluorescent) die almost instantly.

Audio system for the bar includes a volt meter with digital display. Always around 120V.

Bar main A/C unit died again--less than a year old. Called in a different reefer man. Installed new compressor and it stopped within 10 seconds. He spent hours trying to find out what was wrong. Finally he checked voltage at the breaker box on both sides.

Guess what?

Utility company hooked us up to the third leg of three-phase power!!!

Of course this is the same company that allowed an UNSUPERVISED gravity pump/generation reservoir to deteriorate to the point that it collapsed (over a billion gallons) and nearly destroyed one of our nicest state parks and turned a previously clear river into a murky mess.

Steamhead (in transit)

Not only

to court, but also the local media. This kind of utility incompetence is all too common nowadays- remember the clowns in New England who hooked up a low-pressure gas system to a high-pressure source and blew up several homes? If it were one of us it would be all over the papers and TV. They deserve the same.

We pay way too much for such lousy service.

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Mike T., Swampeast MO

Am I right to be incensed?

I gave up after crazy problems during and immediately after the original install.

I guess we're ALL STUPID because nobody bothered to put the voltage meter across EACH LEG of the service entrance.

My friendly reefer man is pissed because we haven't payed bills in a timely fashion after repeated replacements. We used another reefer man because we thought the friendly good one turned incompetent.

Techman

Arrrrrrrrrrrrr!

Hi Mike T. From where I sit thats a realy cool service call and problem!Was that third power leg a "wild " leg? Enjoy!
You do have a right to be upset!

Tony_23

It surprises me

That no one used a volt meter in all this time. The 1st and biggest mistake was the power co's. But, three years and nobody caught this ? To just keep replacing equipment like that and wondering why w/o thoroughly investigating IS a touch on the incompetent side.

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Bob Harper

cicuit testing

In addition to your DMM, Ideal makes a slick circuit tester called the Suretest. The model 165 can test for AFCIs, GFCIs, bootleg grounds, etc. Check it out. Uses the power from the house yet can save data such as how much current tripped the A/G FCI and what the response time was.

Yeah, when things keep going bad, somebody should stop and ask why.
HTH,

Mike T., Swampeast MO

I'm partly mad at myself for not checking the voltage of both legs in the breaker boxes. I just kept looking at the volt meter for the sound system and thinking that the problem wasn't the power supply as it always had a normal reading--even when the big A/C units cycled.

Mike T., Swampeast MO

I wasn't there. Reefer man was showing readings to my business partner. Very high (290v?) with wild fluctuations on one leg--other normal.

We're waiting to hear from the attorney as we want to do this "right". I assume he'll tell us to call an electrician to verify and record the problem before anyone notifies the utility company.

Last year the main sewer backed up numerous times. Telephone company subcontractor had pushed a wire right through the 6" clay sewer line! They tried to worm out of paying because of a "statute of limitations". Took lawyer to prove them wrong. The phone company and the subcontractor are still battling over who is at fault...

EBEBRATT-Ed

I am assuming that this is a single phase service with two hots and a neutral???

Or is it a three phase service?? If it single phase both hots should read the same voltage to neutral and neutral to ground should be 0 volts. If they used the "crazy leg" for one of your hots on single phase by mistake your 240 volt loads will be ok but any 120 volt loads will be screwed up if connected to the crazy leg.

If it is a three phase service you can use the "crazy leg" for one of the three phase legs. You should get the same voltage L1-L2, L1-L3. and L2-L3. Your voltage to neutral will be 120 on two legs and much higher (160) from crazy -neutral. Don't use the crazy leg for any 120 volt loads.

This is a "delta system" a Wye system will have the same voltage from any hot to neutral or ground and no crazy leg.

Ed

Mike T., Swampeast MO

Yes. Simple single-phase in the building. Three phase available on the pole. This was a lumber company DECADES ago and there used to be three-phase service to the building. The three-phase was removed over 20 years ago during a major renovation.

I have ZERO experience with three-phase. About all I know is that three-phase motors are significantly smaller and more efficient than their single-phase cousins and that "phase generators" are used when three-phase isn't available from the utility company.

EBEBRATT-Ed

Mike,

I would deffinatly have a good electrician check this out. Here's why.You said that the building was fed with three phase at one time but is now single phase.

Normially a building that is single phase is fed with 240 volt single phase power 120 volts from each hot - neutral and 240 between the two hots---just like a house job.

3 phase can have several variations. Three phase with a wye connected transformer will give you 208 volts L1-L2,L2-L3 and L1-L3. you will get 120 volts from any hot leg -neutral.

3 phase delta will give you 240 volts between L1-L2, L2-L3, and L1-L3. It will give you 120 volts between two of the hot wires and the neutral however the "other Hot Leg" will give you over 200 volts between the hot and neutral. This will ruin any 120 volt equipment connected to it.

It is possible when the three phase to single phase conversion was made that they inadvertantly used the "crazy leg" for one of the single phase hot wires which is wrong.

I would first check the voltage from each hot -hot 208 volts and it is probly wye connected and 240 volts is delta connected.

The other possibility is loose or coroded connections. I would have your electrician disconnect the power and check all connections meter socket , weatherhead, panel etc. Check the voltage with the power completly disconnected from the building. Hope this helps,

Ed

Maine Doug_38

In one of my former lives

I had responsibility for several commercial buildings. EVERY year we took measurements of loads and voltages on all main and sub panels and building feeds. We had the power Co. disconnect the building while we tightened ALL breakers and feeds in all panels and moved loads to rebalance phases as needed. Took all day on a weekend and could be done as these were office buildings and warehouses. Paid for itself by having consistant power and voltage and clean grounds. Was fortunate to have worked in buildings where we could do that, unlike the 11ty billion sq.ft towers.

JR_4

....Thank goodness--no one got hurt and it was discovered!

Favorite story: Circa 1975
Wisconsin town.
Roto Rooter man called to clean out residential slow running sewer line. He pulled back snake line upon recognizing strong on rush of natural gas from house sewer line. Bldg later proceeds to blow up. Don't remember the casualty issues, if any. Learned that utility had reamed a plastic gas main through house sewer line in street(transecting it). My source: the investigator who handled the case.

Bob Depew

Telephone Co.

We have had one town that has had a few lines in the sewer. They have always paid the bill and bills on any work up to then (fist one went 5 years). But we had some trouble until the city steped in and told them to pay or get out of town. City said it was done on there land. Town of 500 so they all know each other.

EBEBRATT-Ed

Dave,

They don't use single phase to generate the third "wild leg". Three phase wye connected is supplied at 208 volt or at 480 volt between the phase conductors and 120 or 277 volts from each phase to neutral respectivly and has no wild leg. This is the most common form of three phase.

Three phase Delta is usually 240 volts between the phase conductors and because delta has no place for a center tap you get 120 volts from two of the phase conductors to neutral and over 200 volts from the "wild or crazy leg" to neutral. You just can't use the wild leg for any 120 volt loads.


ED