Motor-Generator Sets

Featured Product from Kato Engineering, Inc.


Motor-generator (MG) sets provide load isolation for computers and other sophisticated electrical systems. They can also perform frequency conversion and are used for transformer testing.

  • Rugged and reliable: The motor generator set construction inherently isolates the generator totally from the incoming mains. The generator and the equipment being powered are protected from voltage sags, surges, or spikes that could cause damage.
  • The generator of the motor generator set is built to robust NEMA standards and shrugs off short-circuits and overloads.
  • Generous design and precision construction allow KATO™ Motor Generator Sets to function trouble-free for decades with only occasional routine maintenance. Our customers have generator sets in daily use that were manufactured twenty years ago.
  • Kato Engineering provides service to all of its sets, even those that would be considered ancient by the standards of the electronics industry.
  • Quiet power with low distortion: By careful design of windings, we can produce a generator with distortion as low as 1% THD line-to-line. Normally the neutral on these machines is not connected, so third harmonic is virtually zero for balanced load. By using the optimum pitch, fifth and seventh harmonics may be substantially eliminated, and judicious use of skew reduces higher harmonics including slot harmonics.
  • Kato Engineering's high-voltage form-wound Motor Generator sets permit higher output voltages than are available with random windings, simplifying output transformer construction.
  • Our Motor Generator sets also offer many advantages over solid-state systems

With input of 50 or 60 Hz, output frequencies of 50, 60, or 400 Hz are available as standard. For custom designed systems, fixed frequency outputs from 25 Hz to 1200 Hz may be selected, or we can provide continuously variable frequency using a VFD on the motor. Power capacities range from 10 kVA to 20,000 kVA and up, depending upon system requirements.

Typically, Kato Engineering furnishes a factory-programmed PLC control panel to provide a complete power conversion or isolation system. The panel is usually unit-mounted but can also be free-standing or wall-mounted. The panel will include the motor starter, output circuit breaker, metering, protective relaying, a voltage regulator and any other required components. Manual and automatic paralleling is also available.

Our basic line has the following specifications:

Synchronous motor-generator sets

Hz kVA Volts

50-50 to 25,000 120 to 13,800

60-60 to 25,000 120 to 13,800

60-400 to 400 120 to 600

50-400 to 300 120 to 600

60-50 to 25,000 120 to 13,800

50-60 to 25,000 120 to 13,800

Other frequencies available: RTF