Water & Wastewater industrial application

Water & Wastewater applications

The water sector is modernizing around reliability, automation, and energy efficiency.

Recovered project references include high-pressure water transmission pumps, deep well turbine pumps, seawater intake pumps, and process pump systems.

Transmission pumps
Aeration blowers
Sludge systems
RO pumps

Relevant case studies

Obsolete motor drop-in replacement without site changes

An old and obsolete motor was replaced with an upgraded modern design while keeping the installation footprint stable.

Open Case Study

Sea-water pump synchronous motor replacement

A 60-year-old Westinghouse synchronous motor for a sea-water pump was replaced even though no site drawings remained available.

Open Case Study

Engineering notes for this sector

PAM two-speed controlled-flow operation

Pole Amplitude Modulation motors provide two fixed speeds from a single winding, helping pumps and fans reduce energy use without a full variable-frequency package.

Single-winding, two-speed squirrel cage construction
Oil-filled five-pole speed-changing switch is typically installed close to the motor
Lower-speed starting reduces inrush current and thermal stress

Cooling system enhancement

Aging motors often need improved cooling to handle hotter ambient conditions and longer duty cycles while preserving the existing mounting envelope.

Review cooling path, airflow, heat exchanger selection, and cooling class
Improve thermal margin without changing the foundation, coupling, or terminal arrangement
Recovered example: 4,600 kW motor cooling upgraded from IC511 to IC516 while frame size reduced from 1250 mm to 900 mm

Torque and speed-curve matching

Replacement designs must consider existing load curves, starting current, and speed-torque behavior so the new motor remains compatible with the driven machine.

Match original speed-torque curve and starting behavior
Reduce inrush current where possible
Keep adequate torque safety factor during network voltage drop and soft-start operation

VFD-compatible motor replacement

VFD-compatible motors require review of the original drive design, harmonic effects, insulation stress, and the ability to operate without changing existing drive settings.

Account for THD and high-voltage spike insulation stress
Use motor and VFD design data during replacement engineering
Witness testing can simulate real operating conditions and load

DC-to-AC conversion

Old DC motors can be replaced with AC motors and VFDs when output characteristics are matched to protect the driven machine and process.

Match output characteristics of the existing DC motor
Maintain dimensional and mechanical interfaces
Requires direct access to experienced motor and drive design teams