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

A

Normal

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 750 275 275 275

1

-

275

170 165 160 155 150 150 150 140 135 135 135 135 135 135 135 125 125 120 120 100

135 130 130 130 130 130 125 125 125 125 125 125 125 125 125 125 120 120 120 100

135

115 110 285

255 225

1.5

175 250

130 115 110 285 250 225

275 275

275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275 275

2 3 5

170

235

125 115 110 285 250

225

160 215 150 185 140 175 135 165

125

115 110 270

250 225 275

125 115

110 271 250 225 275 115 110 272 250 225 275 115 110 273 250 225 275 115 110 274 250 225 275 110 200 200 200 275 115

7.5

125 120 120 120 120 120 120 120

10 15 20 25 30 40 50 60 75

130 130

160 150

130 150 130 150 125 140 120 140 120 140 105 140 105 125 100 110 100 110 100 100

115 110 200

200 200 275

115 115

110 200 200 200 275 275 275

110 200

200 200 275 200 200 275 200 200 275

115 110 200

120 115 110 200

120 115 110 200 200 200 275

100 125 150 200 250

120 115 115 115

110 200 200 200 275

110 200

200 200 275 275 275

115 115 -

200 200 200 275 275 275

115 -

- - - -

200200200 -

- - - -

- - - -

70 70 70

80 80 80

- - -

- - -

- -

- - -

- - -

- -

300-350 400-500

100 -

-

-

-

-

TR.11

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