Franklin Subdrive replacement

[grahamk]

I recently had a new 440 foot deep well drilled and the driller installed a constant pressure franklin pump and SD15 subdrive controller.

The SD15 subdrive emits an AM radio signal that can be heard throughout my stereo system whenever the pump runs, which is unacceptable. Franklin came out and spent a day with various filters trying to solve the problem. They could not. Now Franklin and my driller have gone silent on me. That's disappointing, but I need to move on.

I wonder if anyone could recommend another brand of drive that I could use as a direct replacement for the SD15? I really like and would like to keep the constant pressure and don't want to mess with swapping out the pump or tank. I have fished around for something that might work, and it just leaves me confused - sure would appreciate any advice.

Thanks!

 

[Valveman]

All VFD's work the same. They convert normal single phase power into pulsing DC power that works like an AM radio signal. Sometimes those dv/dt filters will help, but usually not. Plus, the more filters there are the more power is being wasted. A VFD is a computer that waste energy and filters cause it to waste even more. Sometimes not being grounded well enough is the problem, and you may not be able to ground any better than it is.

If you want constant pressure with something that solves all pump system problems you will need a Cycle Stop Valve. The CSV has reduced constant pressure pump control down to its simplest form, and simple is what makes a pump system reliable. The CSV doesn't use any power and the pump runs on smooth sinusoidal regular line power. Studies show that in 15 years you will spend $7,000.00 purchasing and replacing VFD's and pumps on average. Where in the same 15 years there will be no maintenance on a CSV system that only cost $3,000.00 to start with. In 30 years there will still be no maintenance needed for the $3,000.00 CSV system, where maintenance and replacement costs of the VFD will exceed $11,000.00. The main goal of a VFD system is to get 3-5 times more of your money in the long run.

The three phase motor locks you into replacing the VFD, usually several times. You can't run a three phase motor on single phase house power without a VFD to convert single phase into three phase. The VFD is like a Tar Baby you can't get rid of. Usually after someone has replaced 2-3 of those expensive VFD controllers they realize they need to bite the bullet and replace the pump with a normal single phase pump than can run on regular power. Then a CSV can deliver strong constant pressure that you like, make your pump system last several times longer than normal, and won't make a bit of electrical interference in your house or stereo.

They can sure make those VFD type pumps sound inviting. It is called marketing, and they spend the most money advertising the things that make them the most money. Which of course will cost you the most money. You won't find a single pump company that will even say a favorable word about the CSV. To them the CSV is a disruptive product that makes pumps last longer, use smaller tanks, and eliminates VFD's. If the CSV was a mouse trap, it would make mice extinct. Pump companies hate the CSV because it works so well, which is the opposite of what they will tell you.