VFD Cable Selection Guide
Cable Properties
Ampacity
NEC Art. 310-16, 90°C
Four Conductors (3 Black with white numbers + G/Y ground)
Related Product Pages
AWG | Amps (3/c + Grid) | AWG | Amps (3/c + Grid) |
---|---|---|---|
22 | 6* | 10 | 40 |
20 | 8* | 8 | 55 |
18 | 14 | 6 | 75 |
16 | 18 | 4 | 95 |
14 | 25 | 3 | 110 |
12 | 30 | 2 | 130 |
*not from NEC
table (Calculated)
Motor Properties
Four Conductors (3 Black with white numbers + G/Y ground)
Selection (NEC Art. 430-22 exc. 2)
Wire size @125% of FLC (4/c cable)
Drive | 230 V 3Ø |
460 V 3Ø |
575 V 3Ø |
Drive | 230 V 3Ø |
460 V 3Ø |
575 V 3Ø |
---|---|---|---|---|---|---|---|
HP | AWG | AWG | AWG | HP | AWG | AWG | AWG |
1/4 | 22 | n/a | n/a | 10 | 10 | 16 | 18 |
1/3 | 22 | n/a | n/a | 15 | 8 | 12 | 14 |
1/2 | 22 | 22 | 22 | 20 | 6 | 10 | 12 |
3/4 | 22 | 22 | 22 | 25 | 4 | 8 | 10 |
1 | 20 | 22 | 22 | 30 | 3 | 8 | 10 |
1 1/2 | 20 | 22 | 22 | 40 | 2 | 6 | 8 |
2 | 18 | 20 | 20 | 50 | ** | 4 | 6 |
3 | 18 | 20 | 20 | 60 | ** | 3 | 4 |
5 | 14 | 18 | 18 | 75 | ** | 2 | 3 |
7 1/2 | 12 | 16 | 18 | 100 | ** | ** | 2 |
NOTE: Above tables reference the suggested wire AWG to use based on Horse Power (HP) and FLC times 125% per NEC Art 430-22 exc. 2.Amperes (FLC) were determined from NEC Art. 430-150: Full-Load Current for Three Phase AC Motors. For Example: For a 5 HP and 460 Volt motor, the FLC is 7.6A.7.6Ax125%=9.5A. The right AWG wire for 9.5A is 18 per NEC Art. 310-16, 90°C.
** Use single conductors
++ Use 4 Conductor Cable
Installation Properties
Voltage Drop Factors
Volts/ft at FLC at 20°C
HP | @ 230 V | @ 460 V | @ 575 V | HP | @ 230 V | @ 460 V | @ 575 V | HP | @ 230 V | @ 460 V | @ 575 V |
---|---|---|---|---|---|---|---|---|---|---|---|
1/2 | .045 | .022 | .018 | 15 | .034 | .043 | .053 | 125 | .020* | .020* | .016* |
3/4 | .064 | .032 | .026 | 20 | .028 | .038 | .047 | 150 | .020* | .022* | .018* |
1 | .056 | .042 | .034 | 25 | .020 | .028 | .036 | 200 | .016* | .025* | .024* |
1 1/2 | .079 | .060 | .048 | 30 | .020 | .032 | .042 | 250 | n/a | .020* | .019* |
2 | .052 | .045 | .036 | 40 | .021 | .027 | .033 | 300 | n/a | .020* | .019* |
3 | .073 | .063 | .052 | 50 | .016* | .020 | .026 | 350 | n/a | .016* | .014* |
5 | .050 | .058 | .046 | 60 | .019* | .019 | .018 | 400 | n/a | .016* | .014* |
7 1/2 | .045 | .058 | .046 | 75 | .024* | .020 | .019 | 450 | n/a | .016* | .016* |
10 | .036 | .072 | .084 | 100 | .020* | .016* | .012 | 500 | n/a | n/a | .016* |
NOTE: Above tables reference the voltage drop over distances. It was determined by using the selection criteria of Motor Properties Table. In order to determine the voltage drop, multiply the length by the data above. For Example: For a 5 HP and 460 V motor, P/N 701804 would be used. For a distance of 200 feet, your voltage drop would be 200x.058=11.6 volts.
*Value is based on using single conductor table.