TABLE OF CONTENTS | 1. | What is a drive? |
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| 2. | What are three reasons why variable-speed drives are used? |
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| 3. | Name three factors that cause the efficiency of an AC motor to improve. |
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| 4. | Coordination of variable-speed drive systems in industry are typically controlled by what type of device? |
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| 5. | Name the basic parts and functions of a variable-speed drive system. |
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| 6. | Name the categories of variable-speed drives and their principles of operation. |
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| 7. | What are the two separate electrical circuits in a DC-drive system? |
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| 8. | What three principles are involved in the operation of an AC drive? |
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Answers
| 1. | A drive is a device that controls the speed, torque, direction, and resulting horsepower of a system. |
| 2. | Efficiency gains, process changes and improvements, and system coordination. |
| 3. | Motor load, the horsepower rating, and the speed of operation. |
| 4. | A programmable logic controller (PLC) or other computer device. |
| 5. | Machine device that performs the work Coupler connects the motor to the machine Motor changes one form of energy to rotating Drive controls the speed, torque, and direction of the motor Controller generates and sends a reference to the drive Power Source supplies power to operate the drive |
| 6. | Mechanical, hydraulic, and electric/electronic: Mechanical device that uses belts, chains, and pulleys to change the output speed through increasing and decreasing of pulley diameters. Hydraulic device that uses fluid and a pump to operate a hydraulic motor. Control of motor speed is done through a valve. Electric/electronic device that controls the speed of an electric motor by means of converting one form of... |
