Induction motor manufacturing costs rise as________________?
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Answer: A. horsepower rating increases but r.p.m. decreases
Explanation
Motors with lower RPM and higher horsepower require more materials and larger frames, increasing manufacturing costs. Low-speed machines require significantly more magnetic core iron and copper conductor mass to produce required torque levels. High-power ratings combined with slow rotational speeds demand massive mechanical structures that drive up material and labor expenses. Torque output in an induction motor is inversely proportional to rotational speed for a given power rating level. Larger frame sizes necessitate heavier casting housings, increased winding copper volume, and extensive machining operations. Electromagnetic design constraints dictate that slow, powerful machines require oversized magnetic cores to avoid saturation.
Higher RPM with lower horsepower reduces required core material volume and lowers overall manufacturing expenses. Increasing both horsepower and speed simultaneously changes electromagnetic scaling factors differently than heavy low-speed designs. Decreasing both horsepower and speed results in smaller, lower-cost machine frames rather than escalating manufacturing expenses.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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