A bad neutral connection is something that needs to be fixed NOW.

The most immediate effect is to not share the 240 volts equally between two 120 volt legs. That means that light bulbs and small appliances could see much too high a voltage and get burned out.

The other risk is that the bad connection may overheat and destroy the wire or things in the box, which could be a quite expensive repair.

It might have some effect on the power consumption, but I would expect that to be minor, not sky high. The metering should accurately reflect what was used.

If you are talking about a single phase residential service, the answers are;

(1) Not likely.

(2) No.

"I found the problem when I used a meter for my initial exploration. When I touched it between hot and neutral, I got instant and massive fireworks. The same thing happened when I touched one lead to hot and the other lead to the box itself."

Call me dense if I'm missing something obvious here, but what type of meter causes 'instant and massive fireworks' when connected across hot and neutral? Not a voltmeter, that's for sure. An ammeter? Sure, that's exactly what you would expect, it is not good for an ammeter to be abused in that way, and what would you hope to measure?
How did you make the leap from fireworks to a loose neutral?
Are you sure that its not your tenant's grow-op that is causing the increased power usage?

... what type of meter causes 'instant and massive fireworks' when connected across hot and neutral? Not a voltmeter, that's for sure. An ammeter? Sure, that's exactly what you would expect, it is not good for an ammeter to be abused in that way, and what would you hope to measure?

BINGO!... sounds like someone had their meter dialed/leaded for measuring amperage (zero resistance path) vs. voltage (several MEGohms impedance path)... sparks fer shure, possible fried landlord... lol.

Are you sure that its not your tenant's grow-op that is causing the increased power usage?

Nyuk, nyuk, nyuk... yeah, are there any rooms tenant won't allow access to? "Oh, uh, don't go in there, wife is sick with Ebola-meningitis-bird-flu"... ;')

Including electric in the rent... and I thought I was generous/gutsy for incl. water, sewer, and garbage.

paulusgnome, indeed, you may be missing something. It was a voltmeter set to 750 ACV scale. And where did you come up with anything about a loose neutral?

billhart, average power consumption has been steadily increasing over customary. In December, it increased by 49% over December 2007. A slightly colder monthly average temperature in December is attributable to some of that increase.

The jughead tenant failing to maintain the HVAC filters as specified is responsible for some excess usage but I'm guessing not too much. Even though he kept the thermostat set at 50° in January and the January avg temp was 3.2° warmer than last year, power consumption still increased by 40% vs. Jan. 2007.

All that power has to be going somewhere and he isn't growing weed. I inspected the entire property. House, barns, workshop, garage, everywhere. No agriculture at all and he's been in extreme conservation mode due to the beating he's been taking on power costs. It's an all-electric home with a conventional electric furnace. The water well and pump were recently rebuilt so that's not the cause of any excess draw.

Regarding the bad neutral, I reckon you quit reading before you got to the final paragraph where I said an emergency electrician resolved the issue. I didn't know that guy and don't particularly trust him so my usual electrician will be coming out next week once he gets loose from the job he's on.

I'm gonna go do some checking on the unbalanced 120v legs you mentioned. I saw something else over there that doesn't look quite right even though, as I said, neither the tenant or his computer UPS software reports any power surges.

I'm trying to figure this out to know if the vastly increased electrical costs are due to my system and do fair compensation to the tenant if it is.

Correction for typo in the following line.

"power consumption still increased by 40% vs. Jan. 2007."

Proper date is Jan 2008, not 2007

OK, so a 'bad' neutral is not a loose neutral? In what way was it 'bad' then?
Try as I might, I still cannot think of any circumstances where clipping a voltmeter across the supply would cause 'instant and massive fireworks'. Apart, that is, from inadvertently dislodging a loose wire, but we've already been told that that was not the case.

Turning to the power consumption issue, you may be able to get some idea of where the power is going by using a clamp meter to check the currents in the various distribution circuits leaving the switchboard. If you find one that is carrying more current than seems reasonable for the load connected, that would point you in the right direction. Try turning off all known loads on that circuit one by one and re-check the current at each step.

If you have tried the above and are still in the dark, a data logger may help identify what is drawing the power. These are often quite expensive, but there are companies that specialise in hiring them out. Also, some power companies have been known to help out in cases like this by supplying and fitting a logger for you. The logger will record the current drawn over a period of a day or so, and this can be the key to identifying the cause of the power drain.

Best of luck in finding the source of the problem Don. I'd be interested in seeing what you discover.

Mark aka Paulusgnome

Thanks Mark. I don't exactly know how that happened. The root cause of the problem had to do with an outbuilding subpanel that was installed in 1995. The electrician I hired to do this job did it rather unconventionally. He mounted a lug to the neutral bus and clamped the neutral cable to that. He also used a large ferrous nut as a spacer between the lug and the bus. Over the years all this crap was so rusty it was rotten. I guess this mess being in such close proximity to the hot bus made something do what it wasn't supposed to do.

Early the next morning, the tenant called me and said he heard a loud pop inside the meter box when he was loading up the kids and then the house went dark. When I got there a bit later, I found the main inside the house had tripped. Next I checked the outside meter box/main panel. The tenant had opened all the breakers there. I gingerly checked what I had checked the day before and got no fireworks. I closed all the breakers on and energized the house. Everything still good and still no fireworks between hot and neutral. I was reading voltage, not sparks. At that point I shut everything down and waited for the electrician. I made him remove the rusty neutral and all other subpanel feeds and clean everything up. No way was I getting close to it.

I honestly don't know what went on but I do know that I don't like it. I know just enough about electricity to know that I don't touch a dang thing until I'm confident I won't get bit. Consequently, I use a meter or a test light to verify everything. I know I didn't have my meter set wrong. If I had, it would have blown. The meter wasn't harmed at all. The probe tips didn't do quite as well. They lost some meat in the deal.

I'll let you know what what we figure out.

fixizin said:

"Including electric in the rent... and I thought I was generous/gutsy for incl. water, sewer, and garbage."

You are gutsy. My tenants pay electricity and garbage and my properties are on private wells/septic systems. Tenants pay for the electricity that pumps their water. I pay nothing toward their utilities.

The wiring to the subpanel is buried but is completely encased in conduit between the two boxes. Not sure about the size. I think maybe it's 2/0 aluminum conductors and there's a pretty good size copper ground wire.

I'm thinking the feeds to the water pump, the A/C and a barn are all direct burial.

It can cause huge amounts of power draw and excessive use. Day before yesterday I discovered I had the same problem.

My well pump was running non stop. Low rpm, then high rpm. The outside security light was blinking on and off. When I turned off the breaker to the well, the security light stopped blinking. The next day I called the power company and they treated it as an emergency and came right out to find a bad connection on the neutral at the single phase transformer. A 220 well pump uses a tremendous amount of electricity. And when the fluctuating voltage is so bad it runs non stop for hours on end, that uses electricity.

A year and a half ago I called and reported a bacon frying sound at the single phase transformer, when they came out they tapped it with a stick from the ground and declared it ok. The problem lasted long enough that when I replaced all the outlets in our shop because nothing would stay plugged in, half of them fell apart in my hands.

Our power bill for our shop had been $50 to $75 for years. Over the past year it had gradually risen to double to 3 times the bill in our home. Last month was $384. The power bill had gotten so bad they called me asking what was wrong.

Once they connected the neutral properly, the well pump will build pressure and turn off every time.