Dear engineers, I would like to know, how a Power Planner III from Energy Smart works in a Three phases induction motor in a water pump.

Is it possible to use this Power planner III togeter wit a variable frecuency driver?

If we add an inteligent control like a PLC with a Variable frecuency driver, for example a pressure control, can we improve our energy saving, instead of installing a Power planner III

Thanks in advance for your answer

Regards

That "Power Planner" is nothing more than another one of the many "energy savers" that are based on the old Nola circuit, as have been discussed at length in this forum. Read all of the other discussions about Nola Energy savers in this forum to get a better understanding of why, for the most part, they are a waste of money.

So the answers to your questions are:

How it works? Read other threads as I mentioned above, this has been explained at length.

Can it be used with a VFD? NO! Absolutely not, you will kill both devices. But why would you anyway? A VFD is much more capable of saving energy than is any Nola controller (such as this Power Planner). But it can only save energy if you can live with varying the speed.

Can you improve your energy use by using an intelligent system with a VFD? Possibly, but it all depends on the nature of your pressure system. IF you were using a Pressure Reducing Valve to modulate pressure output from a constant speed pump, you may very well achieve some additional energy savings benefits from modulating the pump speed to maintain a pressure value rather that the PRV, but there is no way to determine the amount of savings without first carefully studying the existing system use profile. In general though, most people who install VFDs in centrifugal pump applications that involve variable outputs will realize significant energy savings. The other part of this is that many new BFDs now come with all or most of the intelligence you will need if that is all you wanted to do, so the PLC may not even be necessary.

Forget the Power Planner however, that is most likely a waste of money.

EnergySmart went bankrupt prior to that discussion anyways. Only in South America is it being still marketed and supported (spare parts and such are stocked by an ex-distributor there.)
The only applications where there is a measurable reduction in energy is a very intermittent duty motor, and only where there is enough savings (bigger HP) does the ROI actually make sense.
But for sure, I have seen it myself, with a scope meter. These things can work - but very few will do the engineering economics to see the annual savings over investment. If they do, they see there a better ways to save.
Anytime a motor is ran at 100% on VSD, then it's probably more cost effective to install a soft-start. It's only high-horsepower, high duty cycle (18-24 hours per day), and mostly unloaded applications where it would ever create enough savings over the investment to have a payback of less than 3-5 years.