Using variable speed pool pump with SWG

[Motoman]

1. They are far less reliable than a 2-speed pump, especially in areas with thunderstorms (and lighting related power surges). They probably should not be installed in lightning prone areas, like Florida

First, I am new to the site and very new at pools, but i do have a pretty good bit of knowledge on motors, mechanics and physics. I'm enjoying the great education I'm getting by reading the many professional posts. I would love to share some of the knowledge from my field.

With that said, A Metal Oxide Varistor or MOV, can be wired in parallel to each of the line voltage legs to ground, and they are only a couple bucks from Radio Shack. Or you can install a surge protection device to the disconnect box, Home Depot $20

2. Failures in the electronic motor control are common, usually not covered by warranty, with a cost of repair of 70% or more of the cost of a new pump.

most failure in the commutator are caused by surges or brownouts. This causes the NTC thermistor protection device to fail (a very inexpensive repair for an electronic hobbyist). MOV's will take care of this, sacrificing itself before taking out the internal protector. I have yet to tear apart my new Hayward VS pump, but can't imagine it is much different than other ECM motors I have experience with.
Another protection device on VS motors are power chokes. Basically an inductor wired in series with the line input to slow the input current and reduce the harmonics cause by the square wave form. These need to be appropriately sized.

3. Electrical savings, over what a 2 speed pump provides, are significant, but marginally so.

Though residential meters don't allow for a higher apparent power cost doesn't mean we don't pay in other ways. As we continue to build more houses an continue to use poor power factor split phase AC motors, this requires the power company to increase power production and increase the supply line service cables far beyond the what would be needed from more electrically efficient equipment. This is seen in the annual or biannual rate increase for all. For those "GREEN" people, it means a larger carbon footprint.

4. Initial pump cost is almost double what a 2-speed pump + timer costs, so much of the electrical savings is consumed paying for that cost difference.

If the motor and module are properly loaded and protected, these motors will provide years of energy savings. Paying for the difference in less than 2 years when comparing to the cost of an inefficient split phase motor.

Hope I haven't overstepped by greenhorn status.