Large induction Motor Circuit Designer Page
Notes:
CHART OF LOAD MAXIMUM INERTIA (LB-FT) OF VARIOUS MOTOR SIZES
| HP \ RPM | 3600 | 1800 | 1200 | 900 | 720 | 600 | 514 | 450 | 400 | 360 | 327 | 300 |
| 0.5 | 1 | 3 | 8 | 16 | 27 | 42 | 61 | 84 | 112 | 144 | 182 | 223 |
| 1 | 1 | 6 | 15 | 31 | 53 | 82 | 118 | 163 | 216 | 278 | 350 | 431 |
| 2 | 2 | 11 | 30 | 59 | 102 | 158 | 228 | 314 | 417 | 537 | 677 | 832 |
| 3 | 4 | 17 | 44 | 87 | 149 | 231 | 335 | 462 | 613 | 789 | 994 | 1223 |
| 5 | 6 | 27 | 71 | 142 | 242 | 375 | 544 | 749 | 994 | 1281 | 1614 | 1985 |
| 7.5 | 8 | 39 | 104 | 208 | 355 | 551 | 799 | 1100 | 1460 | 1881 | 2370 | 2915 |
| 10 | 11 | 51 | 137 | 273 | 467 | 723 | 1049 | 1445 | 1917 | 2470 | 3112 | 3828 |
| 15 | 16 | 75 | 200 | 400 | 684 | 1061 | 1540 | 2120 | 2814 | 3626 | 4568 | 5620 |
| 20 | 21 | 99 | 262 | 525 | 898 | 1393 | 2021 | 2783 | 3694 | 4760 | 5997 | 7378 |
| 25 | 26 | 122 | 324 | 647 | 1108 | 1719 | 2495 | 3436 | 4561 | 5877 | 7406 | 9112 |
| 30 | 30 | 144 | 384 | 769 | 1316 | 2041 | 2963 | 4081 | 5418 | 6982 | 8799 | 10826 |
| 40 | 40 | 189 | 503 | 1007 | 1725 | 2677 | 3886 | 5353 | 7108 | 9160 | 11545 | 14206 |
| 50 | 49 | 232 | 620 | 1241 | 2127 | 3302 | 4794 | 6605 | 8772 | 11306 | 14251 | 17536 |
| 60 | 58 | 275 | 735 | 1473 | 2524 | 3919 | 5691 | 7841 | 10415 | 13425 | 16923 | 20826 |
| 75 | 71 | 338 | 904 | 1814 | 3111 | 4831 | 7017 | 9671 | 12848 | 16562 | 20880 | 25699 |
| 100 | 92 | 441 | 1181 | 2372 | 4070 | 6324 | 9190 | 12669 | 16833 | 21704 | 27368 | 33688 |
| 125 | 113 | 542 | 1452 | 2919 | 5011 | 7790 | 11323 | 15613 | 20751 | 26760 | 33748 | 41546 |
| 150 | 133 | 640 | 1718 | 3456 | 5937 | 9233 | 13425 | 18516 | 24612 | 31745 | 40040 | 49298 |
| 200 | 172 | 831 | 2238 | 4508 | 7752 | 12064 | 17550 | 24216 | 32200 | 41544 | 52412 | 64545 |
| 250 | 210 | 1017 | 2744 | 5535 | 9526 | 14834 | 21590 | 29802 | 39641 | 51157 | 64554 | 79513 |
| 300 | 246 | 1197 | 3239 | 6541 | 11266 | 17554 | 25561 | 35295 | 46961 | 60618 | 76508 | 94253 |
| 350 | 281 | 1373 | 3723 | 7528 | 12977 | 20231 | 29471 | 40708 | 54177 | 69948 | 88302 | 108799 |
| 400 | 315 | 1546 | 4199 | 8499 | 14662 | 22870 | 33329 | 46050 | 61303 | 79165 | 99955 | 123175 |
| 450 | 349 | 1714 | 4666 | 9456 | 16324 | 25474 | 37139 | 51330 | 68347 | 88280 | 111482 | 137400 |
| 500 | 381 | 1880 | 5126 | 10400 | 17965 | 28048 | 40906 | 56552 | 75318 | 97302 | 122895 | 151488 |
| 600 | 443 | 2202 | 6027 | 12250 | 21188 | 33111 | 48323 | 66842 | 89061 | 115098 | 145418 | 179297 |
| 700 | 503 | 2514 | 6903 | 14057 | 24344 | 38075 | 55602 | 76949 | 102570 | 132602 | 167580 | 206673 |
| 800 | 560 | 2815 | 7757 | 15826 | 27438 | 42949 | 62759 | 86895 | 115872 | 149846 | 189425 | 233668 |
| 900 | 615 | 3108 | 8592 | 17559 | 30477 | 47743 | 69805 | 96694 | 128987 | 166857 | 210984 | 260319 |
| 1000 | 668 | 3393 | 9409 | 19261 | 33465 | 52463 | 76749 | 106360 | 141931 | 183656 | 232283 | 286659 |
| 1250 | 790 | 4073 | 11379 | 23386 | 40735 | 63975 | 93714 | 130004 | 173627 | 224823 | 284518 | 351294 |
| 1500 | 902 | 4712 | 13257 | 27349 | 47753 | 75120 | 110178 | 152990 | 204485 | 264951 | 335484 | 414412 |
| 1750 | 1004 | 5313 | 15055 | 31170 | 54548 | 85945 | 126203 | 175402 | 234613 | 304172 | 385344 | 476208 |
| 2000 | 1096 | 5881 | 16778 | 34861 | 61142 | 96482 | 141835 | 197300 | 264088 | 342584 | 434218 | 536827 |
| 2250 | 1180 | 6418 | 18435 | 38434 | 67552 | 106754 | 157108 | 218728 | 292968 | 380259 | 482197 | 596380 |
| 2500 | 1256 | 6927 | 20028 | 41898 | 73793 | 116784 | 172050 | 239725 | 321301 | 417258 | 529355 | 654952 |
| 3000 | 1387 | 7864 | 23042 | 48523 | 85808 | 136175 | 201028 | 280539 | 376475 | 489410 | 621430 | 769431 |
| 3500 | 1491 | 8704 | 25846 | 54782 | 97258 | 154759 | 228912 | 319930 | 429849 | 559342 | 710812 | 880708 |
| 4000 | 1570 | 9455 | 28457 | 60708 | 108196 | 172613 | 255807 | 358036 | 481602 | 627276 | 797774 | 989110 |
| 4500 | 1627 | 10124 | 30892 | 66327 | 118663 | 189797 | 281796 | 394965 | 531871 | 693383 | 882526 | 1094887 |
| 5000 | 1662 | 10717 | 33163 | 71661 | 128692 | 206358 | 306944 | 430805 | 580768 | 757801 | 965235 | 1198241 |
| 5500 | 1677 | 11237 | 35278 | 76728 | 138310 | 222336 | 331305 | 465626 | 628383 | 820643 | 1046040 | 1299336 |
| 6000 | 1673 | 11689 | 37246 | 81541 | 147542 | 237764 | 354925 | 499488 | 674791 | 882003 | 1125055 | 1398312 |
| 7000 | 1612 | 12400 | 40772 | 90459 | 164920 | 267082 | 400095 | 564535 | 764243 | 1000590 | 1278098 | 1590358 |
| 8000 | 1484 | 12873 | 43786 | 98498 | 180956 | 294501 | 442709 | 626280 | 849549 | 1114091 | 1425008 | 1775146 |
| 9000 | 1294 | 13123 | 46328 | 105725 | 195754 | 320168 | 482968 | 684985 | 931041 | 1222917 | 1566284 | 1953274 |
| 10000 | 1046 | 13166 | 48427 | 112193 | 209395 | 344200 | 521033 | 740861 | 1008986 | 1327399 | 1702330 | 2125219 |
| 11000 | 743 | 13012 | 50110 | 117947 | 221949 | 366698 | 557039 | 794084 | 1083607 | 1427810 | 1833478 | 2291380 |
| 12000 | 387 | 12673 | 51398 | 123024 | 233474 | 387744 | 591099 | 844801 | 1155090 | 1524383 | 1960007 | 2452088 |
| 13000 | -18 | 12156 | 52309 | 127458 | 244021 | 407412 | 623311 | 893139 | 1223596 | 1617313 | 2082157 | 2607628 |
| 14000 | -471 | 11470 | 52860 | 131276 | 253634 | 425762 | 653759 | 939207 | 1289263 | 1706773 | 2200138 | 2758249 |
| 15000 | -970 | 10620 | 53066 | 134505 | 262351 | 442851 | 682518 | 983104 | 1352214 | 1792914 | 2314130 | 2904168 |
Notes:
#1. Motor Data based on 60Hz, Squirrel Cage Motors.
#2. Values are theoretical values based in information in NEMA MG1 Part 20.
#3. Values are for educational purposes only. It is user's sole responsibility to ensure actual motor circuit design conforms to all applicable national and local codes. These values are for educational purposes only. Due to the wide range of motor circuit applications, the author assumes no responsibility for the application of these values.
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