New efficiency standards that take effect next year will directly impact vertical hollow-shaft and other electric motors that are used to pump water in the majority of the nation’s irrigation systems.

Beginning June 1, 2016 these motors — among many others — will be required to meet “NEMA Premium” efficiency standards, or they cannot be manufactured in or imported to the United States. Historically, the motors used to pump irrigation water have not been subject to federal regulation.

What does the new standard mean to you and your pumping system? In a nutshell, it means you should expect some changes the next time you are in the market for a pump motor.

Why Motors Are Regulated        

Federal regulation of motor efficiency is still relatively new, dating back only to the 1992 passage of the Energy Policy Act. EPAct introduced North America’s first energy standards and regulations for HVAC equipment, lamps and a limited number of general purpose motors. Enforced by the Department of Energy (DOE), the new regulations established efficiency requirements using levels defined by the National Electrical Manufacturers Association (NEMA).

In 2007, the Energy Independence and Security Act (EISA) went a step further, establishing energy efficiency standards for a much broader scope of electric motors not covered by the original EPAct regulations. These standards also upped the efficiency ante, requiring these motors to meet new criteria set by NEMA for Premium Efficiency motors.

The first round of changes stemming from the EISA 2007 standards went into effect in December 2010. Round two, which will officially take effect June 1, 2016, will include vertical hollow shaft electric motors. The majority of agricultural well pumps use such motors. The DOE has identified nine motor characteristics to determine if a motor must meet the NEMA Premium standard. They include motors ranging from 1 to 500 horsepower, rated at 600 volts or less, and with a 2-, 4-, 6- or 8-pole configuration. (See sidebar.)

The only pump motors that fall outside the scope of the new DOE ruling are submersible motors and definite-purpose, inverter-fed motors.

What It Means to You

One of the biggest reasons why most motors were historically exempt from EISA and EPAct regulations was a technical one. The DOE had not identified a test procedure manufacturers could use to verify NEMA Premium Efficiency.

That changed in 2014 when the DOE established that motors could be evaluated for NEMA Premium Efficiency using what is known in the industry as IEEE Standard 112 Method B or CSA C390.

But there is a catch: the DOE’s testing procedures rate a motor’s efficiency in “standard” operating conditions, which assumes the motor will operate in an environment with an ambient temperature of 25 degrees Celsius and at an altitude of 3,300 feet or below. Because the procedures call for motors to be tested in a horizontal bearing arrangement with standard deep groove ball bearings, their efficiency ratings also do not factor in the efficiency losses they might experience due to high thrust bearing losses. In other words, a motor’s official efficiency rating — known as the NEMA Nominal Rating — may not reflect its true efficiency in the pumping operation.

Beginning next June, manufacturers will be required to stamp the NEMA Nominal Rating on their motors’ nameplates, signifying that the motor is guaranteed to operate at that efficiency under those standard operating conditions.

Because this rating does not necessarily reflect how a motor will perform in its intended application, motor manufacturers will have to supply a second “full-load efficiency rating” that reflects the motor’s actual efficiency, given the actual site conditions. In most cases, this rating will be lower than the NEMA Nominal Rating.

Why It Matters

It is important for users to understand the difference between a motor’s NEMA Nominal Efficiency and its actual operating efficiency. This information is especially critical when calibrating the equipment used with the motor. For optimum performance, calibration should be based on actual efficiency.

The good news is, once these new motors are in place and your equipment is calibrated, your operation is the big winner.

Is my motor covered by the new regs?

The DOE’s new expanded electric motor standards apply to any motor that has these nine characteristics:

  • Single-speed induction motors

  • Poly-phase, AC, 60 HZ

  • Squirrel-cage

  • Continuous duty (MG-1) or duty type S1 (IEC)

  • 2-, 4-, 6- or 8-pole configuration

  • Rated 600 volts or less

  • NEMA 56 frame size or IEC metric equivalent

  • Between 1 and 500 horsepower (or kilowatt equivalent) • NEMA Design A, B or C or IEC design N or H