Submersible Pump VFD for Borehole Duty

Why dry-run protection is the headline function

The AU820 documentation publishes dry-running (water-shortage) protection as a headline function of the pump line, alongside high-pressure and burst-pipe protection; the AU620 set documentation adds automatic operation logic that keeps a supply system running without an attendant.

Documented features for the duty

• Across the AU620 set documentation: the drive is published in single-phase and three-phase versions, and is documented as compatible with permanent-magnet synchronous and asynchronous motors.
• Constant-pressure PID control from a pressure sensor (0–10 V gauge or 4–20 mA transmitter inputs documented).
• Anti-freeze automatic operation for exposed lines, and anti-rust protection for idle periods.
• Backpack IP54 installation.

Two questions to settle in the enquiry

Cable length. A borehole motor sits at the end of a long cable; state the cable run between drive and motor in your enquiry and ask for the configuration for it to be covered in the quotation. Power source. The drives documented here are mains-powered. If the pump is solar-fed, it falls under the solar pump inverter documentation — the YSG documentation covers solar pump duty, with well dry-run protection documented in the solar context.

The rest of the wellhead

The pump lines' documented functions include constant-pressure PID control — closing the loop from a pressure sensor on the delivery line, on the documented 0–10 V and 4–20 mA inputs — dry-running protection and anti-freeze operation. The AU820 is documented in a backpack format whose documentation specifies waterproof construction. Which additional equipment a given borehole needs is a set-design question: raise it in the enquiry and ask for it to be addressed with the configuration. Where the borehole feeds a set rather than a single tap line, the master/auxiliary architecture on the booster page extends the same drive family to multiple pumps.

And a commissioning note: the pump documentation describes the water-shortage behaviour directly: the system stops automatically, and after a set period restarts automatically for a specified number of times.

Frequently asked questions

Can one drive run both a borehole pump and a booster set?

The pump lines publish master/auxiliary set control across the set documentation; describe the system — pump, motor and duty — in the enquiry and ask for the configuration to be covered in one quotation.

What happens when the well runs dry?

The documented water-shortage (dry-run) protection stops the pump on loss of water; the documentation describes automatic restart after a set period, for a specified number of times, while the shortage persists — ask for the restart behaviour for your set to be stated with the configuration.

Single-phase submersible motors?

The AU620 is documented as a single-phase and three-phase drive. Send the motor's data — including its capacitor arrangement — with the enquiry, and ask for the compatible pump types for the model to be stated in the quotation.