Although it has been nearly 10 years since the successful testing of the world’s first commercially available 100 horsepower single-phase electric motor, SPPS is continuing to expand the awareness and consumer base of this ground-breaking design. Designed for operation on single-phase utility distribution systems, the single-phase motor is the behemoth of the company’s line of large-horsepower single-phase motors, available in sizes ranging from 15 to 100 hp. These large horsepower single-phase motors benefit from several important enhancements made possible through the application of Written-Pole® Technology, a proprietary motor and generator technology developed by John F. Roesel Jr. and Ronnie Barber. The low starting current requirements and high operating efficiency made possible by this technology have enabled designers to dramatically increase the available horsepower that single-phase motors can produce while operating on standard single-phase utility distribution systems.
The starting demand of a Written-Pole® single-phase motor is generally about 25 to 30 percent of the starting demand of an equivalent single or three-phase induction motor, dramatically reducing electrical demand and annoying voltage flicker on utility distributions systems. The 100 hp single-phase motor is the standard in starting performance with a locked-rotor current of 1.3 times the motor’s full-load current while still producing 65 percent of the motor’s rated full-load torque. The peak starting current of 1.50 times the rated full-load current generates 125 percent of the motor’s rated full-load torque providing sufficient torque to start most loads.
Written-Pole® single-phase electric motors are the most energy efficient single-phase motors available in the market, with operating efficiencies comparable to those of energy-efficient three phase induction motors mandated under Canadian and American energy-efficiency regulations. While energy efficiency regulations for large horsepower single-phase motors do not presently exist in either Canada or the United States, Written-Pole® single-phase motors clearly demonstrate the potential for future energy savings.
Testing performed at Hydro Quebec laboratory an independent laboratory in Shawinigan, Quebec, considered to be one of the most advanced motor test laboratories in North America, confirmed the full-load operating efficiency of the 100 hp single-phase motor to be greater than 95.0 percent, comparable to high efficiency three-phase induction motors offered by other manufacturers. This impressive achievement provides for substantial operating savings over comparable diesel or electric options that can dramatically improve the cost-effectiveness of many agricultural and municipal applications.
Applications ranging from single motor installations of 15 horsepower to multiple motor installations totaling 250 horsepower have clearly demonstrated the benefits available from the use of Written-Pole® single-phase motors. End-users seeking to expand or modernize applications with larger horsepower requirements such as irrigation pumping systems, grain drying facilities and gas compression equipment now have an electric option that will enable them to benefit from the low energy costs, reduced labor requirements and convenience of electric power. The replacement of diesel engines in many larger horsepower applications will substantially reduce operating costs as diesel fuel costs continue to rise, while protecting the environment through reductions in the production of greenhouse gases and soil/water contamination from fuel spills.