NEMA motor frame sizes
NEMA frame sizes, defined by the National Electrical Manufacturers Association in standard NEMA MG 1, have standardized the physical dimensions of electric motors since 1926, covering more than 200 designations from 42 to 680. Each size fixes the shaft height, shaft diameter, distances between mounting feet, and other critical dimensions, allowing mechanical interchangeability among manufacturers without modifying the installation.
NEMA standard dimension table
Section titled “NEMA standard dimension table”All dimensions are given in inches (in) followed by their equivalent in millimeters (mm); D = shaft height (center of shaft to base), E = distance from shaft end to center of first mounting hole, 2F = foot length (center to center along shaft axis), BA = foot width (transverse direction), N‑W = keyway length, V = shaft extension from shoulder, U = shaft diameter. The dash “—” indicates that the dimension is not present or does not apply.
| NEMA Designation | D (Shaft Height) | E (Distance to End) | 2F (Foot Length) | BA (Foot Width) | N‑W (Keyway Length) | V (Shaft Extension) | U (Shaft Diameter) |
|---|---|---|---|---|---|---|---|
| 42 | 2 5/8 in / 66,7 mm | 1 3/4 in / 44,5 mm | 1 11/16 in / 42,9 mm | 2 1/16 in / 52,4 mm | 1 1/8 in / 28,6 mm | — | 3/8 in / 9,5 mm |
| 42C | 2 5/8 in / 66,7 mm | 1 3/4 in / 44,5 mm | 1 11/16 in / 42,9 mm | 2 1/16 in / 52,4 mm | 1 1/8 in / 28,6 mm | — | 3/8 in / 9,5 mm |
| 48 | 3 in / 76,2 mm | 2 1/8 in / 54,0 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 1/2 in / 38,1 mm | — | 1/2 in / 12,7 mm |
| 48C | 3 in / 76,2 mm | 2 1/8 in / 54,0 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 1/2 in / 38,1 mm | — | 1/2 in / 12,7 mm |
| 48H | 3 in / 76,2 mm | 2 1/8 in / 54,0 mm | 4 3/4 in / 120,7 mm | 2 1/2 in / 63,5 mm | 1 1/2 in / 38,1 mm | — | 1/2 in / 12,7 mm |
| 56 | 3 1/2 in / 88,9 mm | 2 7/16 in / 61,9 mm | 3 in / 76,2 mm | 2 3/4 in / 69,9 mm | 1 7/8 in / 47,6 mm | — | 5/8 in / 15,9 mm |
| 56C | 3 1/2 in / 88,9 mm | 2 7/16 in / 61,9 mm | — | 2 3/4 in / 69,9 mm | 1 7/8 in / 47,6 mm | — | 5/8 in / 15,9 mm |
| 56H | 3 1/2 in / 88,9 mm | 2 7/16 in / 61,9 mm | 5 in / 127,0 mm | 2 3/4 in / 69,9 mm | 1 7/8 in / 47,6 mm | — | 5/8 in / 15,9 mm |
| 56HZ | 3 1/2 in / 88,9 mm | 2 7/16 in / 61,9 mm | 5 in / 127,0 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 56J | 3 1/2 in / 88,9 mm | 2 7/16 in / 61,9 mm | — | 2 3/4 in / 69,9 mm | 2 7/16 in / 61,9 mm | — | 5/8 in / 15,9 mm |
| 66 | 4 1/8 in / 104,8 mm | 2 15/16 in / 74,6 mm | 5 in / 127,0 mm | 3 1/8 in / 79,4 mm | 2 1/4 in / 57,2 mm | — | 3/4 in / 19,1 mm |
| 140T | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 7/8 in / 22,2 mm |
| 142AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 3 1/4 in / 82,6 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 143AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 1/4 in / 57,2 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 143JM | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 1/4 in / 57,2 mm | — | — | 7/8 in / 22,2 mm |
| 143JP | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 1/4 in / 57,2 mm | — | — | 7/8 in / 22,2 mm |
| 143T | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 1/4 in / 57,2 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 143TC | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 7/8 in / 22,2 mm |
| 143TR | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 in / 101,6 mm | 2 1/4 in / 57,2 mm | 2 5/8 in / 66,7 mm | 1 3/4 in / 44,5 mm | 7/8 in / 22,2 mm |
| 144AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 145AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 145JM | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 1/4 in / 57,2 mm | — | — | 7/8 in / 22,2 mm |
| 145JP | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 1/4 in / 57,2 mm | — | — | 7/8 in / 22,2 mm |
| 145T | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 1/4 in / 57,2 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 145TC | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 7/8 in / 22,2 mm |
| 145TR | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 in / 127,0 mm | 2 1/4 in / 57,2 mm | 2 5/8 in / 66,7 mm | 1 3/4 in / 44,5 mm | 7/8 in / 22,2 mm |
| 146AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 146ATC | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 7/8 in / 22,2 mm |
| 147AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 6 1/4 in / 158,8 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 148AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 7 in / 177,8 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 149AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 8 in / 203,2 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 1410AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 9 in / 228,6 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 1411AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 10 in / 254,0 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 1412AT | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 11 in / 279,4 mm | 2 3/4 in / 69,9 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 1412ATC | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 11 in / 279,4 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 7/8 in / 22,2 mm |
| 162AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 4 in / 101,6 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 163AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 4 1/2 in / 114,3 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 164AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 2 1/2 in / 63,5 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 165AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 5 1/2 in / 139,7 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 166AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 6 1/4 in / 158,8 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 167AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 7 in / 177,8 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 168AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 8 in / 203,2 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 169AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 9 in / 228,6 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 1610AT | 4 in / 101,6 mm | 3 1/8 in / 79,4 mm | 10 in / 254,0 mm | 2 1/2 in / 63,5 mm | 1 3/4 in / 44,5 mm | 1 1/2 in / 38,1 mm | 7/8 in / 22,2 mm |
| 182 | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| L182ACY | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 182AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| L182AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | — | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 182JM | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | — | — | 7/8 in / 22,2 mm |
| 182JP | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 3/4 in / 69,9 mm | — | 7/8 in / 22,2 mm |
| 182T | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 1/8 in / 28,6 mm |
| 182TC | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 3/4 in / 69,9 mm | — | 1 1/8 in / 28,6 mm |
| 182TR | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 4 1/2 in / 114,3 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 1/4 in / 57,2 mm | 1 1/8 in / 28,6 mm |
| 183AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 in / 127,0 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 184 | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 184AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 184JM | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | — | — | 7/8 in / 22,2 mm |
| 184JP | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | — | — | 7/8 in / 22,2 mm |
| 184TC | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 2 3/4 in / 69,9 mm | — | 1 1/8 in / 28,6 mm |
| 184T | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 1/8 in / 28,6 mm |
| 184TR | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 5 1/2 in / 139,7 mm | 2 3/4 in / 69,9 mm | 3 3/8 in / 85,7 mm | 2 1/4 in / 57,2 mm | 1 1/8 in / 28,6 mm |
| 185AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 6 1/4 in / 158,8 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 186ACY | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 7 in / 177,8 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 7/8 in / 22,2 mm |
| 186AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 7 in / 177,8 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| L186AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 7 in / 177,8 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 186ATC | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 7 in / 177,8 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 1 1/8 in / 28,6 mm |
| 187AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 8 in / 203,2 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 188AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 9 in / 228,6 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 189AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 10 in / 254,0 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 189ATC | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 10 in / 254,0 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | — | 1 1/8 in / 28,6 mm |
| 1810AT | 4 1/2 in / 114,3 mm | 3 3/4 in / 95,3 mm | 11 in / 279,4 mm | 2 3/4 in / 69,9 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 1 1/8 in / 28,6 mm |
| 203 | 5 in / 127,0 mm | 4 in / 101,6 mm | 5 1/2 in / 139,7 mm | 3 1/8 in / 79,4 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 3/4 in / 19,1 mm |
| 204 | 5 in / 127,0 mm | 4 in / 101,6 mm | 6 1/4 in / 158,8 mm | 3 1/8 in / 79,4 mm | 2 1/4 in / 57,2 mm | 2 in / 50,8 mm | 3/4 in / 19,1 mm |
| 213 | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | 3 in / 76,2 mm | 2 3/4 in / 69,9 mm | 1 1/8 in / 28,6 mm |
| 213AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 213JM | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | — | — | 7/8 in / 22,2 mm |
| 213JP | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | — | — | 1 1/4 in / 31,8 mm |
| 213T | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | 3 3/8 in / 85,7 mm | 3 1/8 in / 79,4 mm | 1 3/8 in / 34,9 mm |
| 213TC | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | 3 3/8 in / 85,7 mm | — | 1 3/8 in / 34,9 mm |
| 213TR | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 5 1/2 in / 139,7 mm | 3 1/2 in / 88,9 mm | 4 1/8 in / 104,8 mm | 2 5/8 in / 66,7 mm | 1 3/8 in / 34,9 mm |
| 214AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 6 1/4 in / 158,8 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 215 | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | 3 in / 76,2 mm | 2 3/4 in / 69,9 mm | 1 1/8 in / 28,6 mm |
| 215AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 215JM | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | — | — | 7/8 in / 22,2 mm |
| 215JP | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | — | — | 1 1/4 in / 31,8 mm |
| 215T | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | 3 3/8 in / 85,7 mm | 3 1/8 in / 79,4 mm | 1 3/8 in / 34,9 mm |
| 215TC | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | 3 3/8 in / 85,7 mm | — | 1 3/8 in / 34,9 mm |
| 215TR | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 7 in / 177,8 mm | 3 1/2 in / 88,9 mm | 4 1/8 in / 104,8 mm | 2 5/8 in / 66,7 mm | 1 3/8 in / 34,9 mm |
| 216AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 8 in / 203,2 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 217AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 9 in / 228,6 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 218AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 10 in / 254,0 mm | 3 1/2 in / 88,9 mm | 2 3/4 in / 69,9 mm | 2 1/2 in / 63,5 mm | 1 3/8 in / 34,9 mm |
| 219AT | 5 1/4 in / 133,4 mm | 4 1/4 in / 108,0 mm | 11 in / 279,4 mm | 3 1/2 in / 88,9 mm | — | — | — |
NEMA frame designation
Section titled “NEMA frame designation”The NEMA designation system for induction motors combines a two- or three-digit number with one or more suffix letters, and allows three critical mounting dimensions to be deduced without consulting the table. The shaft height is obtained depending on the motor type:
D = two-digit number / 16 for fractional frames 42 to 56; D = (first two digits) / 4 for three-digit T frames.
For example, size 56 indicates a shaft height of 3.5 in (88.9 mm), while 182T corresponds to 18/4 = 4.5 in (114.3 mm). The third digit in integral horsepower frames defines the length group (2F): 0 equals the shortest length, 2 the medium (4.5 in in the 180 series) and 4 the long (5.5 in). Suffix letters provide information on the mounting type or shaft characteristics:
- C: C‑face flange with a standardized bolt circle of 5.875 in (149.2 mm) for size 56C.
- T: re‑rate design per NEMA MG 1 for integral horsepower motors, with reduced dimensions compared to older U frames.
- TC: combination of C‑face flange and T frames.
- JM: close-coupled pump motor, with specific flange and shaft dimensions.
- JP: deep well pump motor.
- H: indicates a 2F dimension larger than standard (e.g., 48H with 2F = 4 ¾ in).
- HZ: extended shaft (V = 2 in) and larger diameter, used in special applications.
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the shaft height of a NEMA 56 motor?
Section titled “What is the shaft height of a NEMA 56 motor?”The shaft height of a NEMA 56 motor is 3 ½ inches (88.9 mm), measured from the base of the mounting feet to the center of the shaft, making it one of the most widely used fractional frames in fans and small pumps.
What is the shaft diameter of a NEMA 213T motor?
Section titled “What is the shaft diameter of a NEMA 213T motor?”The shaft diameter of a NEMA 213T motor is 1 ⅜ inches (34.9 mm), a standardized value that accepts commercial couplings and pulleys without adapters.
What main dimensions define the interchangeability of a NEMA 143T motor?
Section titled “What main dimensions define the interchangeability of a NEMA 143T motor?”Mechanical interchangeability is ensured by the shaft height D = 3 ½ in (88.9 mm), the foot length 2F = 4 in (101.6 mm) and the foot width BA = 2 ¼ in (57.2 mm). These three dimensions guarantee that the motor can be directly replaced in applications with a standard mounting base.
What does the suffix “C” mean on a NEMA 56C frame?
Section titled “What does the suffix “C” mean on a NEMA 56C frame?”The suffix “C” identifies a motor with a C‑face flange. On size 56C, the flange register has a diameter of 4.500 in (114.3 mm) and the four tapped holes are distributed on a 5.875 in (149.2 mm) bolt circle, using ½‑13 UNC screws.
How is the third digit interpreted in a designation like 184T?
Section titled “How is the third digit interpreted in a designation like 184T?”The third digit “4” in 184T corresponds to the long frame length, which sets the distance between the foot holes at 5 ½ in (139.7 mm). A digit “2” would indicate the medium version with 2F = 4 ½ in, and “0” the short version with 2F = 3 ½ in within the same shaft height series.
What is the distance between the centers of the mounting holes on a NEMA 184T motor?
Section titled “What is the distance between the centers of the mounting holes on a NEMA 184T motor?”The longitudinal distance (2F) of the 184T motor is 5 ½ inches (139.7 mm), while the transverse distance (BA) is 2 ¾ inches (69.9 mm), values that define the drilling template for the mounting plate.