Deep Well Pump VFD Project: Cable, Protection and Commissioning Data

A deep-well VFD project needs more than pump power and borehole depth. The supplier should receive the motor nameplate, total motor-cable length, supply conditions, water-level information, required flow or pressure and the proposed protection method.

Long submerged cables and limited motor access make design and commissioning evidence especially important. Output-side components, cable practice and parameter choices must follow the selected equipment documentation and project engineering.

What Information Is Required?

• Submersible motor voltage, current, power, frequency, speed and motor type.
• Pump curve, borehole depth, static and dynamic water levels.
• VFD-to-motor cable length, cable type, conductor size and route.
• Site supply, generator use, voltage variation, altitude and temperature.
• Dry-run, low-water, overload and restart requirements.
• Pressure or level sensor type, range, location and signal.
• Commissioning measurements required by the owner or consultant.

Selection Example

A 15 kW, 380 V borehole motor is installed 180 m below the control location. The nameplate current and full cable schedule are available. The project also requires low-water shutdown and controlled restart after the well recovers.

The VFD is selected by documented output-current capacity after site derating is considered. The cable length is then reviewed against the applicable product guidance to determine whether additional output treatment is required. Commissioning records should include supply voltage, motor current, operating frequency, flow or pressure and protection tests.

Common Mistakes

• Using borehole depth as if it were the motor-cable length.
• Selecting only from kW while ignoring current and motor type.
• Leaving water-level sensing and restart logic undefined.
• Adding output devices without checking compatibility with the selected VFD.
• Commissioning without recording current, voltage and hydraulic performance.

AUSENIST Solution

AUSENIST can review the deep-well motor data, cable schedule and protection concept, then propose a YS620 or YS820 selection basis for confirmation. Support can include parameter-planning inputs, feedback requirements and a commissioning data checklist.

The final solution cannot be confirmed from pump power alone. Very long cables, special motors, generator supplies, high altitude and local electrical requirements need project-specific engineering and qualified installation.

Send us the motor nameplate, quantity, voltage, application and project requirements. We can prepare VFD selection and quotation.