Section 5 Part 4 Section Page 5615of 568 Part 405/08 Page 1/1 Date 09/07 Application Manual for NEMA Motors Application Manual for NEMA Motors External Load Inertia Capability, Wk2 (lb-ft2) HP 1 1.5 2 3 5 7.5 10 15 20 25 30 40 50 60 75 100 125 150 200 250 300 350 400 450 500 3600 Synchronous Speed, RPM 1800 1200 900 720 600 2 2 2 Load Wk (Exclusive of Motor Wk ), lb-ft … 1.8 2.4 3.5 5.7 8.3 11 16 21 26 30 40 49 58 71 92 113 133 172 210 246 281 315 349 381 5.8 8.6 11 17 27 39 51 75 99 122 144 189 232 275 338 441 542 640 831 1020 1200 1370 1550 1710 1880 15 23 30 44 71 104 137 200 262 324 384 503 620 735 904 1180 1450 1720 2240 2740 3240 3720 … … … 31 45 60 87 142 208 273 400 525 647 769 1010 1240 1470 1810 2370 2920 3460 4510 5540 … … … … … 53 77 102 149 242 355 467 684 898 1110 1320 1720 2130 2520 3110 4070 5010 5940 7750 … … … … … … 82 120 158 231 375 551 723 1060 1390 1720 2040 2680 3300 3920 4830 6320 7790 9230 … … … … … … … 514 118 174 228 335 544 799 1050 1540 2020 2490 2960 3890 4790 5690 7020 9190 11300 … … … … … … … … NOTES: 1. Locked rotor and breakdown torques are per NEMA Design A and B for general purpose motors. 2. Class F insulation with standard service factor and temperature rise. 3. Rated voltage and frequency applied. 4. During acceleration period, connected load torque varies as the square of the speed and equal to the rated torque at rated speed. 5. Two consecutive cold starts or one start with motor at rated temperature. Please refer to Section 10 Part 3 for more details on Moment of Inertia.