These are a more efficient pump they have what’s called a soft start. Your standard submersible pump that is mentioned above only has one speed on at 3400 RPM. With a VFD Constant Pressure pump the pump turns on and off slowly only delivering the necessary gallons per minute that is dictated by the usage. For example, on the standard pump when the water pressure in the storage tank drops down to the on pressure the pump turns on and stays on until the tank fills up to the shut off pressure. With constant pressure pump there is no drop in pressure hence their name constant pressure. Also with the soft start they don’t require a heavy draw in electricity either so in the long run they use less electricity than your standard submersible pump. Also since they match the delivery of water to the demand with their soft start and stops they do not require a large water storage tank saving costs on install there.
Constant pressure pumps can deliver water pressure similar to that of having city water pressure. They are run by a computer drive with built in run protection for situations where the well runs out of water or if there is an electrical problem. With the fault log kept in the computer’s memory it makes for quick and useful reference for your technician when he come to troubleshoot the problem.