Does a residential power meter really read the high leg and then multiply that number by 2?

Question

I had previously been told that power meters on your home default to whichever leg pulls the larger amount of current, and multiplies that number by two (which assumes the load in the panel is balanced).

But if the load isn't balanced (as mine is not), then you could pay significantly more for power (as it appears I am).

Is there a source to learn if this is true once and for all?

Thanks. Sean.

Answer 1

No. Utilities are required to use true Watt/hour meters that read both phases.

Answer 2

First, D2, turn your caps lock off.  Typing in caps is like yelling, not polite, hurting my ears . . I mean eyes.

Now the question at hand.  No, it is not possible that you are paying for more power than you are using because your load is not balanced.  The power to your house is single phase, usage for each pole is metered and added to arrive at a total usage for the billing period.

Because residential service is single phase, the power company does not experience any type of imbalance on the line due to your unbalanced load.  The transformer will handle the imbalance without any problem.

I suppose it is worth clarifying before someone hits the thumbs down -- residential service is indeed single phase.  There are two poles, but this is not the same thing as two phases.

Having said that, there are some billing methods in use that can cost you some money depending upon when you use power.  Demand metering is becoming more common on residential accounts as many states deregulate their electric utilities.  Under this method, you are billed a smaller amount for the amount of electricity you use, but you are also billed an additional fee based upon the largest amount of demand you experience during the billing cycle.  If you have two cooling units and both come on at the same time, this would cost you more for the whole month than if the units each ran the same amount of time but they were not running at the same time.  

Another method is differential billing, you pay a different amount for your usage depending upon what time of day or day of the week it is.  If you use most of your electricity during peak demand times it will cost you more than if most of your usage is at off-peak times.

Another side effect of deregulation is the unbundling of charges.  In the past you may have been billed a single amount per Kwh of usage, now you may pay a smaller amount per Kwh for generation, another amount for transmission and a fee for billing.  In theory the total of these should be about what you would have paid under the older billing methods, but in practice they are often more.

The only real source to clarify your situation would be your power company.  They probably will not have the first clue about your balanced load question, but again it is not possible that it is an issue.  They may be able to give you some idea as to why you are seeing a higher bill than expected.  If you think your meter is recording more than you are using, the ask about having your meter checked.  Most will do this once without a charge -- at least they used to.  Deregulation could change that as well, if you are in a state that has gone that way.

Answer 3

I CAN SEE WHERE YOUR COMING FROM,BUT ,BOTH LEGS PULL 120VLT EVENLY,ONCE IT HITS THE BREAKER BOX IS WHEN IT GOS ITS SEPARATE WAY,BUT THAT CAN BE RESOLVED BY THE AMOUNT OF SINGLE POLE BREAKERS YOU HAVE AND WHAT THEY ARE RUNNING IN THE HOUSE.BUT I DO NT KNOW HOW THEY WOULD DETERMINE WHAT IS THE HIGH LEG, I'VE NEVER HEARD OF THAT BEFORE.

  NOW IF YOU HAVE A 3PHASE BOX COMING INTO YOUR HOME TH ATS A DIFFERENT STORY,BUT KINDA DOUBT IT.