Motors

Horsepower Calculation

Horsepower (HP) is a unit of power commonly used to measure the output power of motors.

Formula:

HP = (Volts * Amps * Efficiency * Power Factor) / 746

Formula Breakdown:

Motor Speed Calculation

The motor speed calculation is based on the following formula:

Formula:

Motor Speed (RPM) = (Frequency (Hz) * 60) / Number of Poles

Formula Breakdown:

Result:

kVA Calculation

kVA (kilovolt-ampere) is a unit of apparent power commonly used to size electrical equipment.

Formula:

kVA = (Volts * Amps) / 1000

Formula Breakdown:

kW Calculation

kW (kilowatt) is a unit of real power commonly used to measure the power output or consumption of electrical devices.

Formula:

kW = (Volts * Amps * Power Factor) / 1000

Formula Breakdown:

Amps Calculation when kW is Known

Amps (Amperes) is a unit of current.

Formula:

Amps = (kW * 1000) / (Volts * Power Factor)

Formula Breakdown:

Amps Calculation when kVA is Known

Amps (Amperes) is a unit of current.

Formula:

Amps = (kVA * 1000) / Volts

Formula Breakdown:

Amps Calculation when HP is Known

Amps (Amperes) is a unit of current.

Formula:

Amps = (HP * 746) / (Volts * Efficiency * Power Factor)

Formula Breakdown:

Motor Rating (HP) CURRENT (A) 208V 230V 460V 575V
1/4 1.11 .96 .48 .38
1/3 1.34 1.18 .59 .47
1/2 2.4 2.2 1.1 .9
3/4 3.5 3.2 1.6 1.3
1 4.6 4.2 2.1 1.7
1 ½ 6.6 6 3 2.4
2 7.5 6.8 3.4 2.7
3 10.6 9.6 4.8 3.9
5 16.7 15.2 7.6 6.1
7 ½ 24.2 22 11 9
10 30.8 28 14 11
15 46.2 42 21 17
20 59.4 54 27 22
25 74.8 68 34 27
30 88 80 40 32
40 114 104 52 41
50 143 130 65 52
60 169 154 77 62
75 211 192 96 77
100 273 248 124 99
125 343 312 156 125
150 396 360 180 144
200 528 480 240 192
250 -- -- 302 242
300 -- -- 361 289
350 -- -- 414 336
400 -- -- 477 382
450 -- -- 515 412
500 -- -- 590 472

DC and Single Phase

Full-Load Current in Amperes for DC and Single Phase AC Motors

HP DC Motors Single Phase AC Motors
1/6 3.1
1/4 4.1
1/3 5.4
1/2 7.6
3/4
-- 1.6 2.4
-- 2.0 2.9
-- 2.7 3.6
-- 3.8 4.9
-- 6.9
1 9.5
1 ½ 13.2
2 17
3 25
5 40
9.5 4.7
13.2 6.6
17 8.5
25 12.2
40 20
--
-- 16
-- 20
-- 24
-- 34
-- 56
8.8
11
13.2 29
18.7 38
30.8 55
8 72
10 89
12 12.2
17 16
28 24
80 31
100 38
-- 44
-- 55
--
-- 106
-- 140
-- 173
-- 206
-- 255
46 148
61 185
75 222
90 294
111
--
--
-- 341
-- 425
-- 506
-- 675
148 185
185 222
222 294
294
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