Questions & Answers > What is the multiplier for this meter? Image linked.

I work for a small town library. And for some strange reason our city manager is steadfastly refusing to show us our electric bill. This has caused some suspicion so we wanted to verify that our actual expense matches what is taken out of our budget. Normally I would just call the power company, but the local power station is owned by the city. So we were hoping to find out from an independent source first so we can verify the numbers add up.

Most likely our city manager is just a control freak (he is about most other things), however it would put our minds to rest if you could help us out.

Also, if you could show the math of how you figured the multiplier, it would be a big help in helping us understand, and should the numbers not add up we could point out why there is a problem.

We appreciate any help you can give.

September 19, 2013 | Unregistered CommenterJoe

Below is the formula to solve for an electric meter billing multiplier. The Kr that the formula is equal to is the meter billing multiplier.
Kr = [Kh x Rr x Rs x CTR] / 10,000
There are three values in the formula that you will need to find on the meter or from the meter nameplate in order to use it. From the picture you sent to me I have identified these below:
1) Watthour constant or Kh on the meter nameplate - on your meter this value is .6
2) Register ratio or Rr on the meter nameplate - on your meter this value is 166 2/3
3) Shaft reduction ratio or Rs ratio from the meter itself - on your meter this value is 100/1 (as best I can surmise).
There is a fourth value that you will need to be able to find to solve for the full billing multiplier and this is the CTR. The CTR is the Current Transformer Ratio and this device (the current transformer) is not going to be easily accessible for someone other than local utility personnel. There are energized conductors associated with the current transformer so this is why they are usually locked up. Because these devices present an electrical hazard you must not attempt to gain access to it. The size or ratio of the current transformer is generally based on the size of the main breaker for the building the meter is measuring the power for. From what you are experiencing with the city finding out the CT may prove to be difficult so maybe you can look for the main breaker panel and see if you can find the size of the main breaker there. This may allow you to determine a possible CTR for the above formula but at best it will be an uneducated guess.
From the picture that you attached I have calculated the multiplier for the meter itself and this meter’s multiplier is equal to 1. This meter multiplier does not include the CTR which like I say above is needed to provide the full billing multiplier. From my experience meter installations that use this type, phase, and voltage of meter and generally end up with a CTR that is 20 or 40. So, my best guess for the billing multiplier for you is 20 or 40. It might be 10, 30, or even 80 or higher so what I am offering you is my best guess.
If by chance you are able to get someone from the utility to provide you with a CTR then you can contact me again and I will be able to give you a better guess (again based on my experience) of what the billing multiplier might be.

FYI to anyone trying to see the image, you will need to copy and paste the link into a browser window.

September 30, 2013 | Unregistered CommenterBrad