Manual Accuracy Testing of Watthour Meters

Thank you Sir @SolarEagle this will definitely be of great help.

@lyn Hi Sir, thanks for the information as well

@tchtech thank you sir, but is there a more proper or documented way on how to test such meters using a reference standard, phantom load, some manual switches but without the comparator? I am using a digita reference standard where in it gives the accumulated KWh but since it has no comparator it does not automatically give the accuracy of the said meter.

Most meter manufacturers have a procedure of testing prior to the meter being sold/leaving the factory to ensure accuracy.

Why not contact the meter manufacturer!

Take a look at Kill A Watt Meter - Electricity Usage Monitor | P3

If I am to build a kilowatt meter, I will do the same ,install a voltmeter and and ammeter then process readings by means of calculator circuitry with the possibility to correct the reading for calibration purposes-then it's pretty neat that way.

I agree, one way of doing it manually is to measure the voltage and amperage of the circuit by a "reliable and calibrated tester", though he might have difficulty to know the KVA-hr readings as this would mean he has to measure all the time. A data logger would do just that convenient in his absence. Fluke has this type of tester though cost might be around 4 grand.

Disk type power meters require special tools and test equipment to correctly check and adjust the disk rotation speed and distance of travel.

Each individual meter requires skilled tasks that are specific to original manufacturer, meter application, and type of meter.

You must obtain the OEM manual for the specific meter in question and follow their required procedures otherwise the results will not be accurate and the meter may be damaged beyond repair.

The number of disk revolutions is proportional to the amount of current flowing through the meter and is based upon the meter scaling.

As already stated: Running a known value of current through the meter for a known period of time will yield whether the meter is operational however it will not yield accurate results unless the source is stable and of the correct magnitude.

Your basic premise; i.e., "...the number of revolutions..." Indicates that you have not researched the meter testing process which requires a particular load vs. time sequence to ensure that the meter is accurate at any operating point, any power factor load, and for any time period, especially if the meter is going to be used for revenue/billing purposes. There's plenty on the web, Google is your friend.

Hi guys i appreciate your responses with regards to my concern here. Yeah honestly i am on a process of grasping something new, though it is hard initially but i enjoy the process since it will result into learning something new. It is good to know that there are a lot of people that is also interested in my chosen area.

Thank you so much

Do your own homework. You were assigned it not us. Ask your instructors, those who know what they want as an answer, and they can teach you how to get it.

Good Luck, Old Salt