Useful Motor Technical Information 

By on

inductrial motorsSometimes it’s useful to be able to quickly lookup a piece of technical information. This note is a collection of information related to motors, and in particular ac induction motors.

Typical Motor Full Load Currents

Typical Single Phase Motor Currents

Average Full Load Motor Currents, A Single Phase, 50/60 Hz Motors

kW HP 220V 240V
0.37 0.5 3.9 3.6
0.55 0.75 5.2 4.8
0.75 1 6.6 6.1
1.1 1.5 9.6 8.8
1.5 2 12.7 11.7
1.8 2.5 15.7 14.4
2.2 3 18.6 17.1
3 4 24.3 22.2
4 5 29.6 27.1
4.4 6 34.7 31.8
5.2 7 39.8 36.5
5.5 7.5 42.2 38.7
6 8 44.5 40.8
7 9 49.5 45.4
7.5 10 54.4 50

Values are only typical and manufacturers information should be used where possible.

Typical Three Phase Motor Currents

Average Full Load Motor Currents, A 3 Phase, 4 pole, 50/60 Hz Motors

  Rated Motor Voltage, V

kW

HP
200
208

220

230

380

400

415
433
440

460
500
525

575

660

690

750

1000
0.37 0.5 2 1.8 2 1.03 0.98 - 0.99 1 1 0.8 0.6 - - 0.4
0.55 0.75 3 2.75 2.8 1.6 1.5 - 1.36 1.4 1.21 1.1 0.9 - - 0.6
0.75 1 3.8 3.5 3.6 2 1.9 2 1.68 1.8 1.5 1.4 1.1 - - 0.75
1.1 1.5 5 4.4 5.2 2.6 2.5 2.5 2.37 2.6 2 2.1 1.5 - - 1
1.5 2 6.8 6.1 6.8 3.5 3.4 3.5 3.06 3.4 2.6 2.7 2 - - 1.3
2.2 3 9.6 8.7 9.6 5 4.8 5 4.42 4.8 3.8 3.9 2.8 - - 1.9
3 - 12.6 11.5 - 6.6 6.3 6.5 5.77 - 5 - 3.8 3.5 - 2.5
- 5 - - 15.2 - - - - 7.6 - 6.1 - - - 3
4 - 16.2 14.5 - 8.5 8.1 8.4 7.9 - 6.5 - 4.9 4.9 - 3.3
5.5 7.5 22 20 22 11.5 11 11 10.4 11 9 9 6.6 6.7 - 4.5
7.5 10 28.8 27 28 15.5 14.8 14 13.7 14 12 11 6.9 9 - 6
9 - 36 32 - 18.5 18.1 17 16.9 - 13.9 - 10.6 10.5 - 7
11 15 42 39 42 22 21 21 20.1 21 18.4 17 14 12.1 11 9
15 20 57 52 54 30 28.5 28 26.5 27 23 22 17.3 16.5 15 12
18.5 25 70 64 68 37 35 35 32.8 34 28.5 27 21.9 22.2 18.5 14.5
22 30 84 75 80 44 42 40 39 40 33 32 25.4 24.2 22 17
30 40 114 103 104 60 57 55 51.5 52 45 51 54.6 33 30 23
37 50 138 126 130 72 69 66 64 65 55 52 42 40 36 28
45 60 162 150 154 85 81 80 76 77 65 62 49 46.8 42 33
55 75 200 182 192 105 100 100 90 96 80 77 61 58 52 40
75 100 270 240 248 138 131 135 125 124 105 99 82 75.7 69 53
90 125 330 295 312 170 162 165 146 156 129 125 98 94 85 65
110 150 400 356 360 205 195 200 178 180 156 144 118 113 103 78
132 - 480 425 - 245 233 240 215 - 187 - 140 135 123 90
- 200 520 472 480 273 222 260 236 240 207 192 152 - 136 100
160 - 560 520 - 300 285 280 256 - 220 - 170 165 150 115
- 250 - - 600 - - - - 300 - 240 200 - - 138
200 - 680 626 - 370 352 340 321 - 281 - 215 203 185 150
220 300 770 700 720 408 388 385 353 360 310 288 235 224 204 160
250 350 850 800 840 460 437 425 401 420 360 336 274 253 230 200
280 - - - - 528 - - - - - - - - - 220
315 - 1070 990 - 584 555 535 505 - 445 - 337 321 292 239
- 450 - - 1080 - - - - 540 - 432 - - - 250
355 - - 1150 - 635 605 580 549 - 500 - 370 350 318 262
- 500 - - 1200 - - - - 600 - 480 - - - 273
400 - - 1250 - 710 675 650 611 - 540 - 410 390 356 288
450 600 - - 1440 - - - - 720 - 576 - - - 320
500 - - 1570 - 900 855 820 780 - 680 - 515 490 450 350
560 - - 1760 - 1000 950 920 870 - 760 - 575 549 500 380
660 - - 1980 - 1100 1045 1020 965 - 850 - 645 605 550 425
710 - - - - 1260 1200 1140 1075 - 960 - 725 694 630 480
800 1090 - - - 1450 - 1320 1250 - 1100 - 830 790 - 550
900 1220 - - - 1610 - 1470 1390 - 1220 - 925 880 - 610

Values are only typical and manufacturers information should be used where possible.

Motor Derating

Motor rated output refers to continuous duty according to DIN EN 60 034-1 at a frequency of 50 Hz, a coolant temperature (CT) of 40 o C and site altitude of up to 1000. For other conditions motors need to be derated accordingly.

Altitude above sea level Coolant temperature in oC
m 30 30 to 40 45 50 55 60
1000 1.07 1.00 0.96 0.92 0.87 0.82
1500 1.04 0.97 0.93 0.89 0.84 0.79
2000 1.00 0.94 0.90 0.86 0.82 0.77
2500 0.96 0.90 0.86 0.83 0.78 0.74
3000 0.92 0.86 0.82 0.79 0.75 0.70
3500 0.88 0.82 0.79 0.75 0.71 0.67
4000 0.82 0.77 0.74 0.71 0.67 0.63

Frame Size

ac induction motorIEC Publication 60034 has standardised on motor frame sizes for various power outputs to enable interchange ability between manufacturers. Ratings according to IEC frame sizes (IEC 60034/1)

Rated output, kW
Frame Size 2 Pole 4 Pole
63B 0.25 0.18
71A 0.37 0.25
71B 0.55 -
71C 0.75 0.55
80A 0.75 0.55
80B 1.1 0.75
80C 1.5 1.1
90S 1.5 1.1
90L 2.2 1.5
90LB 2.7 2.2
100L 3.0 -
100LA - 2.2
100LB 4.0 3.0
100LC - 4.0
112M 4.0 4.0
112MB 5.5 5.5
132S - 5.5
132M - 7.5
132MBA - 9.2
132MB - 11.0
132SA 5.5 -
132SB 7.35 -
132SBB 9.2 -
132SC 11.0 -
160M 15.00 11.0
160MA 11.0 -
160L 18.5 15.0
160LB 22.0 18.5

The meaning of the standardised letters in the size designation for sizes 90-132 are:

  • S = small
  • M = medium long
  • L = long version.


Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus



Post Authorship

In 2011, with the introduction of it’s Panda search ranking algorithms, Google introduced tools for determining the original author of posts.  The intention...

Closed Doors

"I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong...

IEC 60287 Current Capacity of Cables - Rated Current

In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example.  We then looked at one...

Post Editing Tips

If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive.  However, there are...

Windows Live Writer and myElectrical

When making adding a Note to our site we have a great online WYSIWYG editor and things are pretty simple.  However, if you prefer you can write, manage...

Lead us, Warleader

Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."' Reading is something I do...

9 power supply issues solved by using a UPS

Installation of a UPS can help in reducing problems due to issues with the power supply.  A lot of people relate this to nine key issues.  Depending on...

Sony Pocket eBook Reader

For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...

Tips for a better Low Voltage Protection Discrimination Study

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults. ...

Introduction to Current Transformers

Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note