Durable, energy-saving products for the oil field

Phase Technologies has engineered the 1LH and 3LH series of variable frequency drives (VFD's) to be an extremely robust and flexible solution for oil and gas pump operation.

LH-series drives have a NEMA 3R outdoor rated chassis, insect guards, and most models are rated to 50C (122F). Internally they are designed around 20-year rated film bus capacitors and an indirect cooling design that keeps the main cabinet clean and free of debris. If any problems should arise, all units are fully field serviceable.

The active front end technology on the 1LH and 3LH series VFD's guarantee IEEE 519 compliance without any additional filters. Low harmonics are becoming a necessity in many areas due to increased utility regulation. The active front end also enables the LH series to regenerate power to the grid during a pump jack down stroke. Rather than wasting this energy by feeding it into a dynamic braking resistor (DBR), the LH product line instead uses it to reduce overall utility costs by 10-30%.


Power at your fingertips

1LH and 3LH series drives are flexible and simple to customize to any pumping application

  • Two 4-20mA and one 0-10VDC analog inputs
  • PID algorithm
  • Four programmable digital inputs
  • Optional MODBUS via RS-485
  • Fault sensor detection
  • V/f and sensorless space-vector torque control
  • Torque control

Simple keypad and easy setup

  • Identical keypad and setup on all models
  • Bright and readable screen, even in direct sunlight
  • Messages and prompts in clear, concise, language


The Phase Technologies 1LH is a phase converting VFD that generates three-phase power from a single-phase source. The 3LH should be specified where utility or other three-phase power is available.

Both the 1LH and 3LH share one of the most robust and flexible designs available, that can be customized through the on-site 508A Panel Shop.

Panel Shop options: two-contactor system bypass, MCCB service rated disconnect, HOA switch, speed potentiometer, sinewave filter, dV/dt filter, surge protection, heater, lights, auxiliary power supply, pad mount kits/legs.

Read more about the Panel Shop