Product Manual

Much of this information consists of standards defined by the National
Electrical Manufacturers Association (NEMA). These standards are
widely used throughout North America. In other parts of the world, the
standards of the International Electrotechnical Commission (IEC) are
most often used.
Driven Load - Mechanical Requirements
• For a motor to drive a load properly, it must produce enough
torque to accelerate from standstill to operating speed, and to
supply enough power for all possible demands without exceeding
its design limits.
• To specify the motor properly, the following characteristics of the
load should be considered:
1) Running characteristics:
• Continuous running, constant load.
- horsepower requirement
• Continuous running, varying load
- peak horsepower requirement
• Cyclical load
- peak torque and horsepower requirements
2) Speed
• Constant speed
• Multi-speed
- what speeds required?
• Adjustable speed
- determine needed speed range
3) Starting and Stopping
• Frequency of starting and stopping
• Starting torque requirement
• Acceleration restrictions
• Requirements for braking
- mechanical
- plugging
From this information the size and design characteristics of the motor, as
well as control and braking requirements can be determined.
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