VFD application for small Community Water System

[edwards1800]

I am designing a community water supply for a small community (about 30 homes). In the past, we have used two or more wells with hydropneumatic storage, and put all the controls (and water treatment, if necessary) in a pumphouse. Recently, the pumphouse part has become an expensive part of the project (it depends on the construction style chosen, of course). I am wondering about using a simple VFD, with smaller tanks, and then put the controls in a small enclosure (without water treatment).

I have looked at the residential VFD's, like the Grundfos SQE
and the Goulds Balanced Flow. However, I want the reliability of two wells, and I don't think that those residential controllers work in multiple pump applications.

I have also looked at the Aquavar CPC. That looks cool. I think I can use one or two of these, using a small pressure tank and small enclosure, and meet my requirements.

Can anyone give me advice about this? How does the price of these controllers compare with a larger pressure tank?

In the past, I have sized the tank to minimize start/stops of the pump motor. How does the VFD controller protect the pump motor from excessive starts/stops?

 

[SteveWag]

The Aquavar CPC works very well. The built in logic is better than tryin to set-up a PLC/VFD system. If one well can be used to supply the demand it gets very simple, just alternate with a time clock. The fact that the CPC is a VFD means that many more starts per hour are possible.

I don't know about costs for "larg" tanks.

It is VERY important that the load side reactor be installed.

Are you disenfecting?

Steve Wagner

 

[edwards1800]

Thanks for replying - I think I put this question in the wrong forum.

We probably will add Cl and F. In the past, we have used diaphragm or peristaltic pumps for chemical addition.

I think LMI and Stenner both have VFD-type pumps available to match flowrate, but do you have experience with this setup? Can I really get a chemical feed pump that will feed at the proper rate (and adjust quickly) matching the aquavar CPC's varying flow?

 

[glorifiedplumber]

Was curious to see what you decided to do and what you found out. We have been encountering the same issues with the increase expense of pressure vessels. I was personally concerned about leakage in systems at night forcing the pump to run all night and consume alot of power/gal pumped.