Lapp Online Catalog: VFD Selection Guide

VFD Selection Guide

Motor Properties AWG Size Selection Chart
Drive HP	230V 3ø AWG	460V 3ø AWG	575V 3ø AWG		Drive HP	230V 3ø AWG	460V 3ø AWG	575V 3ø AWG
1/4 - 3	18	18	18		60	2/0	3	4
5	14	18	18		75	4/0	2	3
7 1/2	12	18	18		100	300 MCM	1/0	2
10	10	16	18		125	500 MCM	2/0	1/0
15	8	12	14		150	*	3/0	2/0
20	6	10	12		200	*	300 MCM	4/0
25	4	8	10		250	*	400 MCM	300 MCM
30	3	8	10		300	*	*	400 MCM
40	2	6	8		350	*	*	500 MCM
50	1/0	4	6		400 - 500	*	*

Note: The above table references the suggested wire AWG to use based on Horse Power (HP) and the Full Load Current (FLC) times 125% per NEC Art. 430-22 (A). Amperes (FLC) were determined from NEC Art. 430-150: For Example: For a 5 HP and 460 Volt motor, the FLC is 7.6A x 125% = 9.5A. The right AWG wire for 9.5A is 18 per NEC Art. 310-16, 90ºC. See Table 310-16.


Voltage Drop Factors Volts at FLC @ 20ºC
Drive HP	230V 3ø AWG	460V 3ø AWG	575V 3ø AWG		Drive HP	230V 3ø AWG	460V 3ø AWG	575V 3ø AWG
1/2	.017	.008	.007		30	.020	.032	.042
3/4	.025	.012	.010		40	.021	.027	.033
1	.032	.016	.013		50	.023	.020	.026
1 1/2	.046	.023	.019		60	.016	.019	.018
2	.052	.026	.021		75	.012	.020	.019
3	.074	.037	.030		100	.011	.022	.021
5	.050	.058	.046		125	.008	.047	.022
7 1/2	.047	.058	.069		150	.008	.041	.015
10	.036	.072	.084		200	.006	.011	.013
15	.034	.045	.053		250	N/A	.010	.011
20	.028	.038	.047		300	N/A	.008	.009
25	.020	.028	.036		350	N/A	.008	.009

Note: The above table references the voltage drop over distances. It was determined by using 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 460V motor, P/N 701804 would be used. For a distance of 200 feet, your voltage drop would be 200 x .058 = 11.6volts.

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