How to Calculate Capacitor Rating for a Motor
Recommended capacitor rating for direct connection induction motors to improve power factors to
0.95 or better at all loads. This table will help you calculate the required capacitor size relative to motor size.
Example: For a 10hp motor, with a motor speed of 750 RPM, the rated capacitor required will be 4 kVAr.
Capacitor rating in kVAr when motor speed is:
Motor Power (3ph) Motor Speed (RPM)
kW | hp | 3000 | 1500 | 1000 | 750 | 600 | 500 |
---|---|---|---|---|---|---|---|
1.50 |
2 |
.5 |
1 |
1 |
1.5 |
1.5 |
1.5 |
2.20 |
3 |
.75 |
1 |
1 |
1.5 |
2 |
2 |
3.70 |
5 |
1 |
1.5 |
1.5 |
2.5 |
3 |
3 |
5.50 |
7.5 |
1.5 |
2 |
2.5 |
3 |
4 |
4 |
7.50 |
10 |
2.5 |
3 |
3 |
4 |
5 |
5 |
9 |
12 |
3 |
3 |
4 |
5 |
6 |
6 |
11 |
15 |
3 |
4 |
4 |
6 |
6 |
6 |
15 |
20 |
5 |
5 |
6 |
6 |
8 |
10 |
18.50 |
25 |
6 |
6 |
6 |
8 |
10 |
12 |
22.50 |
30 |
6 |
8 |
8 |
10 |
12 |
14 |
25 |
35 |
8 |
8 |
10 |
12 |
14 |
14 |
30 |
40 |
8 |
10 |
10 |
14 |
14 |
16 |
33 |
45 |
8 |
10 |
12 |
14 |
16 |
18 |
37 |
50 |
10 |
12 |
14 |
16 |
18 |
18 |
40 |
54 |
10 |
12 |
14 |
16 |
18 |
20 |
45 |
60 |
12 |
12 |
14 |
18 |
20 |
22 |
51 |
70 |
12 |
14 |
18 |
18 |
22 |
24 |
55 |
75 |
14 |
16 |
18 |
20 |
22 |
26 |
59 |
80 |
14 |
16 |
20 |
20 |
24 |
28 |
63 |
85 |
14 |
18 |
20 |
22 |
24 |
28 |
68 |
90 |
16 |
20 |
22 |
24 |
26 |
30 |
72 |
95 |
16 |
20 |
24 |
24 |
28 |
30 |
75 |
100 |
18 |
22 |
24 |
26 |
28 |
32 |
79 |
105 |
18 |
22 |
24 |
26 |
30 |
32 |
80 |
110 |
24 |
26 |
28 |
30 |
34 |
32 |
90 |
125 |
22 |
26 |
28 |
30 |
34 |
36 |
100 |
136 |
24 |
28 |
28 |
30 |
34 |
38 |
105 |
140 |
24 |
28 |
30 |
32 |
36 |
40 |
110 |
150 |
26 |
28 |
30 |
32 |
36 |
42 |
120 |
160 |
28 |
30 |
32 |
34 |
38 |
46 |
123 |
165 |
28 |
30 |
32 |
36 |
40 |
48 |
126 |
170 |
30 |
32 |
32 |
36 |
40 |
48 |
129 |
175 |
30 |
32 |
34 |
38 |
42 |
50 |
135 |
180 |
30 |
34 |
34 |
38 |
44 |
50 |
140 |
190 |
32 |
34 |
36 |
40 |
46 |
52 |
150 |
200 |
32 |
36 |
36 |
44 |
46 |
54 |