1. Can you explain to me just how "Max Demand Works" Your new "Dash" software seem to indicate that it resets. Software shows a count down to reset. How does the 15/30/60 intervals work. Average ? over the interval? Does Max Demand mean (=) Peak Demand from the last time it was Zeroed?
Some utility customers are charged for Max Demand, this is usually a charge to Industrial customers to cover the cost of the increased need to grid infrastructure needed to support industrial customers. These customers are charged in 15, 30 or 60 minute Demand Periods. You can set the meter to calculate the Max Demand in any of these time periods. If you set the Demand Period to 15 minutes, the Max Demand is calculated as an average over 15 minutes.
If you are using 1000 watts for 15 minutes steady the Max Demand will be 1000 watts. If you use 1000 watts for 10 minutes and then have a spike in usage of 13,000 watts for 1 minute and then 1,000 watts for 4 minutes you Max Demand will be something like 1,200 watts. So, Max Demand is not the highest point in your usage, it is an average over the 15 minute time period.
Max Demand is an always increasing number (until reset). If you have a Max Demand of 1000 watts and then a Max Demand of 1,500 watts, it will stay at 1,500 watts until it goes higher, or gets reset. Generally you would want to record and then reset your Max Demand on the last day of your billing cycle.
2. Just for chuckles I set it to 15 minutes. Max Demand went higher than I have ever seen it before ?
The other interesting fact I noticed is that In the year or so I have been tinkering with my EKM I have never before had a capacitive power factor. My power factor has alays in the pass been inductive. Currently shows L1 C95% and L2 C63%. To the best of my knowledge all my stuff should be inductive. Refrigerators and Freezers.
Assuming the meter was not moved or setup differently (backwards). There could be any number of reasons why your power factor could have changed. I would assume you are correct that if all you have are inductive loads then you would expect an inductive power factor. What I am unclear on is how much a capacitive load in your own building or in your neighbors building would affect your power factor reading. If you turn off your inductive loads (motors, refrigerators, freezers,etc) what happens to your power factor? Admittedly, we have some holes in our understanding of how power factor and power factor correction works, but we are working on it.
The other anomaly I noted is the L1 & L2 watts don't compute.
As I recall Power (Watts) = Volts times Amps times power factor. I don't get the same numbers that the EKM does.
It should be somewhat close, but depending on how many amps you are seeing this alone could throw off your real-time calculation just because amps are only displayed to tenths of an amp. The difference between 1.1 amps and 1.2 amps can translate to a large swing in your calculated watts. Our meters make 2500 calculations per second on each line. They do calculate using volts x amps x power factor. In the case of the EKM Omnimeters, the overall kWh will be 0.5% accurate.
