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Faulty Meter?

Posted by chisue (My Page) on
Sat, Nov 6, 10 at 9:53

My last two (actual read) bills from our electric power company (ComEd) show greater kWh useage than I expected, given our cool late summer and autumn. We didn't use the A/C at all.

The company refuses to put in an order to check the lines and meter until after the next monthly reading (early December). After the order is placed, it could be another month before anyone comes out to do the check.

The meter reader seems to be recording accurately, but when I look at the meter, it's spinning like crazy -- while we have nothing drawing heavy power inside the house. How can I check to see if the meter is reflecting some unknown power draw in our house?

Our current bill for the month of October shows 2152 kWh.
Our 2009 bill for the month of October showed 1078 kWh.

Our current bill for the month of September shows 1236 kWh.
Our 2009 bill for Sept. (warmer weather; A/C use) shows 1229 kWh.

The only *new* electrically powered items in the house are a 40" Sony LCD TV, replacing a 36" Sony tube-TV, and a Nintendo Wii-Fit game.

Other power draws, in the house from the time it was built in 2001, are: Refrig-Freezer, cooktop, oven, microwave, small kitchen appliances, NuHeat under the tile floor in one bathroom, lights, laptop computer, router, cordless phones, the new TV and one old 13" tube TV, garage door openers.

I'm paying almost double for electricity, this year over last, but I'd thought that was due to rate increases.

I'm 30 miles north of Chicago. The meter is not new. We did have a four-hour power outtage Oct. 26 and have had several 'blips' (unusual in our nine years residence here).

Follow-Up Postings:

RE: Faulty Meter?

Go to your main panel and shut off all the breakers and then the main breaker, then check the meter.

It should have stopped sompletley at this point.

Turn on the main and check again. It still should be stopped since all the branch circuits are still off.
Turn on the breakers one at a time and check the meter after each is turned on.

If you have an electric water heater you might start with that. A broken element can leak a lot of current all the time.

RE: Faulty Meter?

put an ammeter around one and then the other service cables. multiply amp readings by 120 and then add them togrther. compare with readings on your meter. if there is a difference, call your poco.

RE: Faulty Meter?

the meter on your house measures watt-hours, the in phase product if the current and voltage.

Voltage times current only equals watts in an AC system if the power factor os 1.00 (straight resistive load).

It does not read just amps or voltage, but eh time integrated product of volts x amps x power factor.

Clamp on ammeters are way less accurate than the POCOs meter.

They are good for approximate current measurements only (no matter what accuracy they claim).

RE: Faulty Meter?

Before getting too wrapped around the axle, I'd start taking readings off the meter and look at the ones on the bill. It's possible one month got a misread or something.

RE: Faulty Meter?

try the main thing, first.

RE: Faulty Meter?

This is a mystery to me. This afternoon when I checked it, the meter wheel was not spinning rapidly. However, the dials show we've used 1178 kWh's since the meter was read 11/03. How could we be using almost 400 kWh's per day?

DH and I did what you suggested, Brickeye. The meter did stop completely with all power off, and it did not spin wildly even when all circuits were back on, one by one.

Here are our readings going back a year. Some winter months are estimates, but I only have my last three bills.

For useage in:

Oct. '09 - 952
Nov. '09 - 1205
Dec. '09 - 1537
Jan. '10 - 1213
Feb. '10 - 1244
Mar. '10 - 1009
Apr. '10 - 812
May '10 - 1146
June '10 - 1652
July '10 - 2739
Aug. '10 - 895 (actual)
Sep. '10 - 1236 (actual)
Oct. '10 - 2152 (actual - read Nov. 3)
Today - 1178 (actual - by me Nov. 6)

NOW what?

We have a gas water heater, clothes dryer, furnaces, small boiler to power supplemental HW heat under one room. Dehumidifiers in basement have been off for weeks. No A/C for months.

RE: Faulty Meter?

weird. could there be a power leak?

RE: Faulty Meter?

The last three months (Aug/Sep/Oct 2010) average out to 1427 KWh/mo, which is 47.6 KWh/day. That's an average draw of just about 2KW, which works out to an average of just under 20A at 120V.

This is not hard to believe.

The only incongruity I see is that the three-day reading YOU did seems grossly out-of-place compared to the 30-day readings done by the power company.

No disrespect intended, but I am assuming you misread the meter.

RE: Faulty Meter?

I'd bet your reading on 11/6 is actually 2178. Take a look at the link, specifically the 4th example.

Here is a link that might be useful: How to read an electric meter

RE: Faulty Meter?

Here is one way to test a kiloWatt hour meter for accuracy. This is not a precise method, though it can be pretty reasonable if done over a rather long period of time. However, in many cases it can screen for gross inaccuracy.

Shut off all the breakers. Find one which feeds only known receptacles (preferably only one - this might be a recept for the laundry, a sump pump, or the like. Turn on ONLY that breaker.

Read the meter.

Plug in a known, fairly substantial load. One example would be a 1500 watt electric space heater (but be careful; some don't consume the rated power - checking it with a Kill-a-Watt or similar meter would be a good idea).

Operate the known load for as many hours as you can. The larger the known load and the longer you run it, the better the precision of this test. Make sure you use NO other electricity in the house for that entire time (which is why you should have all the other breakers off).

Multiply the (measured if possible) wattage of the appliance(s) by the number of hours and divide by 1000. This is the number of kiloWatt hours that should have been consumed. For example, if you ran two 1500w heaters for 10 hours, you should have used 30 kWH.

Read your meter again. It should have recorded something quite close to the value you calculated in the previous step.

If so, the problem probably not the meter; you need to find out what's consuming the extra energy in your house. If not, then you should recontact the power company and tell them what you did to check.

Again, I emphasize that this is not a lab-accurate test, but it may give you a thumbs up/down on your kWH meter.

RE: Faulty Meter?

For example, if you ran two 1500w heaters for 10 hours, you should have used 30 kWH.

and roasted your cat.

RE: Faulty Meter?

run the heater outside.

RE: Faulty Meter?

and roasted your cat.

Nah, they all come with outstanding external insulation. :)

I had a cat years ago who used to walk into the burning fireplace, saunter across behind the grate, and walk out the other side. I never found so much as a singed hair on him. Why did he do it? To show off, I guess. I kept looking around for the other cat who was daring him to do it.

Seriously, 3000w of resistance heat in most houses this time of year will barely raise the temperature at all - and with all the other power off, even the furnace won't be running, so it's likely to be a bit chilly. Besides, I've seen living rooms and kitchens in some houses that have 1500 watts or so in recessed cans (and they still have dark corners and shadows).

RE: Faulty Meter?

pharkus, you are correct. I DID misread. I apologize.

The Nov. 3 number, as recorded by the meter reader, was 43355. I MIS-READ the meter as 44533 yesterday. Today the meter reads 43560. So, we've used 205 kW in 4 days or about 51 kW per day.

I averaged the useage for Aug., Sept., Oct., and Nov. 2009; it's 40.4 kW per day, so 51 still seems high, especially because we didn't use our A/C at all this late summer/early fall and we DID use it in 2009.

I've called our electrician. He's coming Monday morning.

I notice an animal (chipmunk or larger) has dug a hole in the garden bed about two feet from the electric meter. Relevant? (And if it IS, is this my problem or ComEd's?)

RE: Faulty Meter?

If it is before your meter it will have no effect on you usage. If it did chew into the wire and cause an issue it would be the utilities responsibility. Before the meter is their responsibility everywhere I know of.

RE: Faulty Meter?

''Besides, I've seen living rooms and kitchens in some houses that have 1500 watts or so in recessed cans''
my christmastree uses around that and it does NOTHING. a 1500w heater heats my shed nicely. odd, isnt it?

RE: Faulty Meter?

... 1500 watts of lights are emitting a large amount of energy in the form of light, and significantly less (we hope) energy in the form of heat.

1500 watts of resistance heat is emitting just that: 1500 watts of heat.

There's quite a difference...

and the comment about the cat was more a poor attempt at a humorous musing than anything... davidr clearly got it. And yes, they are fairly well-insulated.

Now, if you've got a smelly steaming arcing chipmunk carcass lying around in the yard near the meter, that is surely sucking up some power, and may be affecting your bills. If the animal simply damaged the wire and left, under its own power, without singed fur and a newfound respect for ductile aluminum, then that particular damage, while it should definitely still be repaired, is probably not consuming power.

15 watts will heat a small surface to soldering temperature. If you're trying to account for a kilowatt or more of average loss, then it isn't taking place in the small area of a damaged cable, or else it would have melted clean through the cable long, long ago, and you'd have a MUCH bigger problem.

I sincerely doubt the ability of a chipmunk to reliably dissipate 1KW of energy also.

RE: Faulty Meter?

If you have any buried cables(to a light pole or shed) that are damaged, it could be leaking to ground. When you see the meter spinning faster than you think it should be that is the time to turn off the breakers and determine which circuit is burning the power.

RE: Faulty Meter?

Wow, I'm really failing to think today. I should just stop. :)

I considered hot-to-neutral leaks (and dissipating 1kW in that small a space would *NOT* work) but totally failed to think of the earth itself.

This is NOT my day.

RE: Faulty Meter?

1500 watts of lights are emitting a large amount of energy in the form of light, and significantly less (we hope) energy in the form of heat.

Actually, incandescent lights are about as efficient as a space heater in turning electrical energy into heat energy. You get the light for free.

I have heard of, but have never witnessed, leakage to ground occuring in water pumps. I don't know how common it is nor do I know the actual loss mechanism.

Other possible sources of loss to ground are damaged underground cables (which could be feeders to outbuildings, water pumps, or septic aerators). The tipoff with these is sometimes an area of the ground where the snow melts off in winter.

Another is fractured elements in electric water heaters, including undersink boiling water dispensers.

I've never seen it happen, but I wonder if a sumbersible sump pump could fail this way.

Most of these faults can be found by isolating the circuits one by one to identify where the loss is happening.

RE: Faulty Meter?

THANK YOU, all! I cancelled the electrician and am going to just keep an eye on the meter, checking to see if I can catch the wheel spinning like a top again. I can always give the guy $90 for showing up and more per hour as he tries to isloate a culprit. My DH isn't 'handy' and I didn't find anything when I did the power cut and gradual resoration switch by switch.

After my big error on reading the meter, I'm a little cowed. Maybe we ARE using 20% more power this fall than we did last year. (50 kW vs. 40 kW.) We just 'fell back' to CST.

BTW, Our phone and electrical lines are buried.

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