In accordance to recent changes in motor efficiency laws, it is now mandatory that continuous duty motors for integral gearmotors be Premium Efficient. It is important to recognize that this requirement only applies to continuous duty motors. Motors rated for intermittent operation (for non-continuous applications) are not required to be Premium Efficient. Premium Efficient motors have more rotating mass (or inertia) and this increased inertia takes energy to start and stop. In fact, in many dynamic or high cycling applications, a Premium Efficient motor can actually consume more electrical energy than a low inertia, lower efficiency design.
The rated motor efficiency in itself doesn’t tell the whole story about energy consumption. The correct perspective for energy savings is to focus on the consumed energy for a whole system and not the motor rated efficiency alone. A higher rated motor efficiency does not ensure lower energy usage in an actual application.
Continuous Duty vs. Intermittent Duty
The basic decision for determining Continuous
Examples of Intermittent Applications
- Crane drives (travel & hoist)
- Hoists & lifts
- Metering pumps
- Packaging equipment
- Punch presses
- Slide gates
- Winders & coilers
Examples of Continuous Applications
- Bucket elevators
- Bulk material handling conveyors
- Continuous flow pumps
- Continuous mixers
Submitted by Nord Drive Systems.