If any members here have a flexible well poly pipe, you must have this tool.

[Real1shepherd]

So they don't really call them 'demand systems' anymore, but VFD Constant Pressure Systems. VFD stands for 'variable frequency drive'.

Advantages are soft start, constant pressure, reduced space for controls/pressure tank and the ability to recognize and adjust for demand. On a conventional pump, when it's cued to come on, it's full amperage startup and that generates heat...lots of it. And as I said earlier, the cycle needs to be at least a minute long, depending on pumps size, to cool that motor back down. VFD's don't have this issue.

Also when you've got really deep wells and long wire runs, going with a three phase VFD can really start to save dollars with soft start and constant pressure systems.

It would seem that in some parts of the country, VFD's are very popular and asked for. I loved the Grundfos SQE system....but they had reliability issues back then. But, the good news is that VFD's have been out long enough that the total difference in cost might be as little as $100. So conventional systems don't blow them out of the water anymore in the price wars.

Kevin

 

[rancher2]

Kevin I have worked on a lot of equipment with VFD'S in the industrial setting, refrigeration compressors, cooling tower pumps and fans. Lots of mixers on big stainless steel tanks. I use several in my own shop on the farm to run three phase equipment with single phase power. I can't say I have been around a well pump that had a true VFD on them. The Grundfos SQE system was the only one that varied the speed of the pump I had been around. That's been years ago now. I try to stay away from well work as much as I can. I am not up on the latest and greatest out there currently. Not for sure what the well guys are currently installing around here on new wells. I need to check that out.

 

[Real1shepherd]

Yeah. hear that...just trying to get myself up to speed. I'm more curious than anything, as I don't intend at my age to get back into pulling pumps. I still have the truck I used, but the puller is long gone.

The Grundfos SQE system was incredibly sophisticated for its time of release. But with all that, you have to have reliability. Pulling a submersible pump out of a well to replace is laborious/$$$ unless it's really shallow and can be done by hand. Few well pumps I ever set were that shallow and I was always by myself too.

Kevin