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Mathcad - 07-04

# Mathcad - 07-04 - PU 0.99 T rated ⋅ = T BD 2.00 T rated...

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T PUC 630.24lbf ft = T BDC 855.326lbf ft = T LRC 900.343lbf ft = T PUC 1.40 T rated = T BDC 1.90 T rated = T LRC 2.0 T rated = From tables 7-3, 4, and 5, the multipliers are 200% for Locked rotor, 190% for breakdown, and .7(200%) for pullup d. Assuming the motor is a NEMA Design C, find the minimum locked rotor torque, breakdown torque, and pull-up torque T LR230 123.797lbf ft = T LR230 0.25 T LR = c. If the motor starts at one-half rated voltage, it will produce one-fourth of locked rotor torque since torque is proportional to voltage squared: T PU 445.67lbf ft = T BD 900.343lbf ft = T LR 495.189lbf ft = T
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Unformatted text preview: PU 0.99 T rated ⋅ = T BD 2.00 T rated ⋅ = T LR 1.10 T rated ⋅ = From tables 7-5, 6, and 7, the multipliers are 110% for Locked rotor, 200% for breakdown, and .9(110%) for pullup b. Assuming the motor is a NEMA Design B, find the minimum locked rotor torque, breakdown torque, and pull-up torque T rated 450.171lbf ft ⋅ = T rated 150 5252 ⋅ 1750 lbf ⋅ ft ⋅ = T rated Hp 5252 ⋅ n r = a. Find the rated torque for this machine Hp P out = n r 1750 rpm ⋅ = V line 460 volt ⋅ = P out 150 hp ⋅ = Problem 7-4: Solution...
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