Standard Motor Catalog

Section TR Technical Reference Guide

The following tables compare NEMA Polyphase design for several performance criteria Table 5: Comparison of Polyphase Designs NEMA Design Starting Current Locked- Rotor Torque Breakdown Torque % Slip Applications

Broad applications including fans, blowers, pumps, machined tools Normal Starting torque for fans, blowers, rotary pumps, unloaded compressors, some conveyors, metal cutting machine tools, misc machinery. Constant load speed. High inertia starts such as large centrifugal blowers, flywheels and crusher drums. Loaded starts such as piston pumps, compressors and conveyors. Constant load speed. Very high inertia and loaded starts. Choice of slip to match load.

High to medium Normal

A

Normal

Max 5%

B

Low

Normal

Normal

Max 5%

C

Low

High

Normal

Max 5%

D

Low

Very High

N/A

N/A

5-8% 1) Punch presses, shears and forming machine tools. 8-13% 2) Cranes, hoists, elevators and oil well pumping jacks.

LOCKED ROTOR TORQUE

Table 6: Minimum Locked Rotor Torque - NEMA, MG-1, Part 12 (% Full-Load Torque)

Design A and B (ref. NEMA Table 12-2)

Design C (ref. NEMA Table 12-3)

Hp Design D RPM @ 60 HZ 3600 1800 1200 900 720 600 514 1800 1200 900 1800 1200 900 RPM @ 50 HZ 3000 1500 1000 750 - - - 1500 1000 750 1500 1000 750 1 - 275 170 135 135 115 110 285 255 225 275 275 275 1.5 175 250 165 130 130 115 110 285 250 225 275 275 275 2 170 235 160 130 125 115 110 285 250 225 275 275 275 3 160 215 155 130 125 115 110 270 250 225 275 275 275 5 150 185 150 130 125 115 110 271 250 225 275 275 275 7.5 140 175 150 130 125 115 110 272 250 225 275 275 275 10 135 165 150 125 120 115 110 273 250 225 275 275 275 15 130 160 140 125 120 115 110 274 250 225 275 275 275 20 130 150 135 125 120 115 110 200 200 200 275 275 275 25 130 150 135 125 120 115 110 200 200 200 275 275 275 30 130 150 135 125 120 115 110 200 200 200 275 275 275 40 125 140 135 125 120 115 110 200 200 200 275 275 275 50 120 140 135 125 120 115 110 200 200 200 275 275 275 60 120 140 135 125 120 115 110 200 200 200 275 275 275 75 105 140 135 125 120 115 110 200 200 200 275 275 275 100 105 125 125 125 120 115 110 200 200 200 275 275 275 125 100 110 125 120 115 115 110 200 200 200 275 275 275 150 100 110 120 120 115 115 - 200 200 200 275 275 275 200 100 100 120 120 115 - - 200 200 200 - - - 250 70 80 100 100 - - - - - - - - - 300-350 70 80 100 - - - - - - - - - - 400-500 70 80 - - - - - - - - - - -

TR.11

Data subject to change without notice. 02/23 • www.gemotorswolong.com