Deep well pumps ?????

[TheGoose]

Ah, I see the marketers have been here LOL.

The problem with that kind of thinking is that you see that "the pump uses less electricity". Well, Duh, because it's not pumping as much water. VS Pumps can go down to as low as 30 HZ (full speed = 60 hz 3450 rpm)....but they probably can't make any pressure and not much flow at 30 hz....which sorta eliminates the efficiency. In fact, you could make a strong argument that they use MORE electricty at low speed because they are less efficient at making pressure at lower speed. Conversely, they become MORE efficient at a higher speed than 60 hz. So it depends on which side of the curve you run on. Most tend to fall on low flow like running the sink or the shower etc.

It gets very complicated very quickly, but rest assured that VS does not really save money when used in a typical WW system. It DOES supply constant pressure, which is the real reason.

Consider that the avg. well owner doesn't use more than $10-15 per month on electricty anyways and the "energy efficiency" argument quickly falters.

A quick reply on the variable speed.

The purpose of a variable speed pump is to be more energy efficient. That is the only advantage to them. As a WW installer, you probably are more familiar than I am with all of the different types of pressure systems. The variable speed pump (motor actually) does not have to run at constant rpms every time it is turned on. I believe (and it has been a while) that the standard submersible motor runs at 3840 rpm's when started. It can not run at less than 3840 rpms. It is either running at this rate, or it is not running at all. A variable speed can run at 50 rpms, or 100, or 500, etc. All the way up to 3840. So, it consumes less electricity. Hence, the energy efficiency.

The problem with them, is that it takes a lot of electronics to make this happen. Sitting in water, all those electronics......... Well, you get the idea.

If you want more information, Look at the Grundfos SQ pump line. What I will tell you, is that we had tons of problems with these when they were new. But that was 10 years ago. I have a newer version in my constant pressure system now, and I haven't had any problems with it. So far. It is 3 years old.

 

[RJD2516]

Sound logic. Learn something new on this site every time I read it.

 

[mdelmarcelle]

We recently built a new house and drilled a well. The water is a bit more shallow, I think around 120 feet. We got a Grunfos pump too. We went with the variable speed. It's a bit more money, but the pressure is always very consistent. We can run multiple faucet, showers, etc. and there is not noticable change in flow or pressure. Comparing this to neighbors/family that have the old style constant speed pumps with large pressure tanks, I think you see more pressure dips and less ability to run multiple faucets at the same time.

Good luck with the well!

 

[RJD2516]

Sound logic. Learn something new on this site every time I read it.

 

[tacomania]

We just recently put in a constant pressure system. Grundfos pump paired with Franklin motor and mono drive. Supplier said they have had problems with the Grundfoss motor in our area burning out because of the inconsistent power supply so they only use Franklin drives now and no problems. Still might be a good idea to have a pressure tank if the power goes out...at least there is a couple flushes left in the system that way.

 

[RJD2516]

Yep, Franklin makes a very reliable motor. They have been doing it forever. I think in the thousands that I tested, I had one that didn't start first try.