|
The Energy
Policy Act of 1992 (EPAct) established minimum-efficiency
levels for all new general purpose electric motors manufacturerd
after October 1997. These levels have been accepted as the
definition of an "energy-efficient" motor by the National
Electrical Manufacturers Association (NEMA) in its MG-1
Standard and throughout the industry. In addition, most
manufacturers currently offer products that exceed the EPAct
minimum-efficiency levels by a significant amount. In 1996,
the Consortium
for Energy Efficiency (CEE) estabished a premium-efficiency
motor specification that has been used by several utilities
and energy efficiency organizations that promote
efficient motors. In response to market confusion as to what
was a "premium-efficiency" motor, NEMA established a new "premium"
specification in 2001.
- NEMA
Premium Motors:
 NEMA has established a new set of efficiency
levels for integral horsepower induction motors. These include
the following motor characteristics:
single-speed; polyphase; 1-500 hp; 2,4, and 6 pole squirrel
cage; NEMA Design A or B; and continuous rated. The
NEMA Premium Motors program
specification outlines the nominal efficiency requirements
that manufacturers need to meet to label their products
with the NEMA Premium label (see logo). When specifying
or selecting a new motor, look for NEMA Premium motors.
Most
manufacturers now offer NEMA Premium motors.
The design
and material choices that a motor manufacturer makes determines
the efficiency of a given electric motor. This efficiency represents
a tradeoff with the cost and operating characteristics, such
as torque and in-rush current. With the implementation of EPAct,
the "standard" motor, in almost all cases, meets the "energy-efficient"
definition. More efficient and higher quality materials are
used in premium-efficiency motors, which can cost between 15
and 30 percent more than an EPAct motor.
Most
manufacturers have introduced electronic versions of their
product catalogs that assist customers or distributors in
selecting the best motor for the application. Motors that
meet the NEMA Premium definition are prominently identified
in these catalogs. But even with these catalogs, it is difficult
for a customer to compare several manufacturers' products.
To address this need, the MotorMaster+®
motor selection program is available. MotorMaster+® contains
a database that includes list price, full-load speed, and
full- and part-load efficiency for more than 24,000 motors,
including ODP and TEFC motors. The database allows customers
to compare a motor to all other similar motors and determine
the economics of selecting the more efficient model.
|
