It's actually a formula of finding the sweet spot on the equipment to know exactly what freq you run them @ for the same performance, but every reduction in freq is a savings.
The idea is the motors are all over built for worst case scenarios, full load mentality, when in fact we rarely get use that capacity. In our case, it is across the line starts with the 40HP pump and of course the consumption. It does let off some of the draw, but it is still running un necessarily for load unload
I was looking at soft starters and then after a lot of research I came across some Danfoss VFD literature and other information about studying the process and just decided we would send a signal to automatically send them in sleep mode, this is the 15hp collector and the pump, during load/unload and cleaning. Using the automation of the VFD the operator is out of the equation
we just did this
We are in the process of going from 6k watts in flourescent to 2k in LED bulbs, and from a 2 ton central air system to Mitsubishi split systems for the AC
I was looking to kill the peak demand charges and by skinning the cat all around with consumption reduction, we can petition if we can get our kwh reduction in line, for a demand charge to be reduced
We have already reduced our trash expense 1700 a year in better planning, 7000 in workmans comp, and now we are looking @ the electric for 6k this year
Anyway we got a Akron edgebander and it has blower on it that runs the compressor non stop, we have to turn the air off to it while not in use.
Then the damn granite guys run the daylights out of the compressors for polishing
I started doing the math, it's definitely the big consumers, but it's all across the board for a reduction, especially when we realized the ac runs 24/7 in the office because the vac pump is such a heat producer it taxes the ac.
Anyway, I bought 2 used VFD's on ebay @ a substantial savings