electric bill

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102 Inspector

Senior Member
Location
N/E Indiana
Occupation
Inspector- All facets
I had a similar problem with my bill and found that one of the wires to my hot tub had corroded enough that the connection created additional resistance. The wire showed definite signs of heat build-up however still had enough to operate the tub "properly". Took about an hour to find the cause after checking breaker by breaker and watching the meter spin. Took about ten minutes to repair and cost retruned to normal.
 

kwired

Electron manager
Location
NE Nebraska
Would you agree, if the electrode system jumpers (GES) are line side, at meter or further upstream, any neighbor's power will remain line side of other fuse boxes?
No. May be more likely but not impossible. Current in a grounded conductor follows all available paths, the majority follows the lesser resistance paths, but any available path will carry some current. This is true for any conductor, but a grounded conductor typically has so many potential paths we don't always think of some of them as being a path.

I had a similar problem with my bill and found that one of the wires to my hot tub had corroded enough that the connection created additional resistance. The wire showed definite signs of heat build-up however still had enough to operate the tub "properly". Took about an hour to find the cause after checking breaker by breaker and watching the meter spin. Took about ten minutes to repair and cost retruned to normal.
It will take the same amount of energy to raise a fixed amount of water a certain temperature. If you have additional resistance in the circuit you will simply heat it at a slower rate, but will still use the same amount of energy over a longer time to do the same work. Now you will have some heat loss from that poor connection, but I doubt it is significant enough to create a noticeable change in the monthly energy bill.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
131223-0927 EST

102 Inspector:

Can you provide more details?

I agree with kwired.

Consider the following assumptions and analysis:

Your tub has a 5000 W heater at 240 V. That is a resistance of 11.5 ohms. The resistance in the bad connection is 11.5 ohms to obtain the maximum power point. Now each resistance dissipates 1250 W. This a lot of power in one small location. Will it melt the wire? Probably not. Since the tub power is 1/4 its normal value, then it will take 4 times as long to heat the tub, or 4 times as long during the heating part of a keep warm cycle, but the off time will remain the same.

Input energy to heat the tub normally is 5*Hours in kWh. With the equal series resistance the heating time is 4 times longer, but at 2500 W input, or 2 times the normal energy required. Half of the available energy was lost in the unwanted series resistance.


Did you use the power company meter to measure energy or power? Was the problem you discovered simply a series resistance problem, or some sort of shunt resistance?

.
 

kwired

Electron manager
Location
NE Nebraska
Seriously?!?!
10 watts in a bad connection could melt the insulation and the wire.
I kind of thought that was maybe worst case possibility, and if it did happen would not last for very long at all and then you end up with open circuit condition and definitely should be no excessive energy bill involved.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
As mentioned several times earlier, the fault which could use that much power and not be noticed would be dissipating that power in a nice 10 ohm earth contact resistance.

Sent from my XT1080 using Tapatalk
 

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
Ask if a Smart Meter has been recently installed by the POCO. If so then his billing rate may have changed to Time of Use and the peak rate during 12pm - 6PM can be as high as 3X the off-peak rate. :slaphead:
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
POCO should be able to help............

POCO should be able to help............

If you've tried everything suggested and still haven't found the problem (or I just didn't read the post that said what you found), most power companies can put a digital recorder on the service that will graph usage patterns and show exactly when and how much power is being used. I've been in the metering end of utilities for over 30 years and I can truthfully say that VERY FEW meters ever speed up. They either test slightly slow or non-functional. The solid state meter failure mode is to quit altogether or have some sort of communication failure that requires a replacement meter. Just my personal observations, though.
 
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