Should You Upgrade To A VFD?

 This blog post is specifically for those who have variable speed drives within their submersible pump system to maintain constant pressure.

Variable frequency drive can be good or bad for you, depending upon your situation.

In terms of efficiency, it’s not that they are highly efficient. If a pump works outside its operating range or at slower speeds, it is less efficient. So in the home application, it would not be very efficient since the water requirement is generally only 2-3 GPM.

To refill pressure tanks, generally, 1-2 minutes are sufficient for a conventional pump. If you have a standard sized tank, then between pump cycles, around 20-25 gallons can be used using a conventional pump

If we talk about the cost compared to conventional installation, the installation of VFD is a bit more expensive.

The reason people are motivated to get VFD’s is to attain constant water pressure. But even if you use mechanical means, which are not very expensive, still constant water pressure can be achieved. Some of these mechanical means are pressure regulating valves, cycle stop valves, and cycle guards. But note that though mechanical options are good, still their overall efficiency in providing constant pressure would be lesser than VFD’s.

 Some functions that VFD offers that make it right:

·       At the expense of an efficient cycle, protection is offered.

·       They offer constant pressure. But for this, mechanical valves can be used as well as they do the same thing.

·       VFD protects the motor from damage that could occur in various situations. But compared to VFD, you can go for motor protection devices as well since they have comparatively a very low price than VFD’s.

·       In 3 phase motors, there is greater reliability at an overall level, and since it offers a soft start, it helps to prolong the motor’s useful life.

·       VFDs are compact

So when should you get VFD for your water system?

·       If you have small agriculture or community systems where the range of flow is quite vast.

·       Your well is extremely deep or when your well’s distance from the electrical source is very long. A longer wire size may be needed, but like other electronic wires don’t have wear and tear. But check the wire’s length per drive limit by consulting the manufacturer first.

·       If in a standard system, larger pressure tanks with non-VFD are used. If you are dealing with space constraints, a VFD with a smaller pressure tank can be utilized.