Those working with electric motors are aware of the recent revision to the 2007 EISA regulationsregarding minimum motor efficiency requirements for continuous duty electric motors. But many applications in the material handling industry aren’t continuous operation.
The use of premium efficient motors in intermittent duty applications may actually cost you operational energy. For intermittent or cyclical operation you could save energy and money by using a non-premium efficient motor. As a result, NORD continues to offer low inertia, non-premium efficient motors as an option for our customers. These motors are rated for intermittent duty and are not to be used in continuous duty applications.
The basic decision for continuous vs intermittent is rather easy. If the motor is switched on, and runs continuously, then the motor should be rated for continuous duty. If the motor is switched on for a short time, or has a cyclic operation, such as indexers, palletizers, diverters and more, then the motor can be rated for intermittent operation. Intermittent operation motors have no efficiency requirement. Premium efficient motors can use more energy because they have more rotating mass (or inertia). This increased inertia takes more energy to start and stop, therefore in many high cycling applications, the premium efficient motor can actually consume more energy.
NORD is ready to assist you in determining if a continuous or intermittent duty motor is appropriate for your application and all of your other material handling and power transmission needs.
