A200 Motor Ratings Data

Motor Ratings Data

Ampere Rating of AC and DC Motors

Ampere ratings of motors vary somewhat, depending upon the type of motor. The values given below are for drip-proof, Class B insulated (T Frame) where available, 1.15 service factor, NEMA Design B motors. These values represent an average full load motor current which was calculated from the motor performance data published by several motor manufacturers. In the case of high torque squirrel cage motors, the ampere ratings will be at least 10% greater than the values given in the following table.

Caution—These average ratings could be high or low for a specific motor and therefore heater coil selection on this basis always involves risk. For fully reliable motor protection, select heater coils on the basis of full load current rating as shown on the motor nameplate.

Ampere Ratings of Three Phase 60Hz AC Induction Motor



hp
Syn. Speed RPM
200V
230V
380V (1)
460V
575V
2200V


1/4
1800
1.09
0.95
0.55
0.48
0.38
-

1/4
1200
1.61
1.4
0.81
0.7
0.56
-

1/4
900
1.84
1.6
0.93
0.8
0.64
-

1/3
1800
1.37
1.19
0.69
0.6
0.48
-

1/3
1200
1.83
1.59
0.92
0.8
0.64
-

1/3
900
2.07
1.8
1.04
0.9
0.72
-

1/2
1800
1.98
1.72
0.99
0.86
0.69
-

1/2
1200
2.47
2.15
1.24
1.08
0.86
-

1/2
900
2.74
2.38
1.38
1.19
0.95
-

3/4
1800
2.83
2.46
1.42
1.23
0.98
-

3/4
1200
3.36
2.92
1.69
1.46
1.17
-

3/4
900
3.75
3.26
1.88
1.63
1.3
-

1
3600
3.22
2.8
1.7
1.4
1.12
-

1
1800
4.09
3.56
2.06
1.78
1.42
-

1
1200
4.32
3.76
2.28
1.88
1.5
-

1
900
4.95
4.3
2.6
2.15
1.72
-

1-1/2
3600
5.01
4.36
2.64
2.18
1.74
-

1-1/2
1800
5.59
4.86
2.94
2.43
1.94
-

1-1/2
1200
6.07
5.28
3.2
2.64
2.11
-

1-1/2
900
6.44
5.6
3.39
2.8
2.24
-

2
3600
6.44
5.6
3.39
2.8
2.24
-

2
1800
7.36
6.4
3.87
3.2
2.56
-

2
1200
7.87
6.84
4.14
3.42
2.74
-

2
900
9.09
7.9
4.77
3.95
3.16
-

3
3600
9.59
8.34
5.02
4.17
3.34
-

3
1800
10.8
9.4
5.7
4.7
3.76
-

3
1200
11.7
10.2
6.2
5.12
4.1
-

3
900
13.1
11.4
6.9
5.7
4.55
-

5
3600
15.5
13.5
8.2
6.76
5.41
-

5
1800
16.6
14.4
8.74
7.21
5.78
-

5
1200
18.2
15.8
9.59
7.91
6.32
-

5
900
18.3
15.9
9.6
7.92
6.33
-

7-1/2
3600
22.4
19.5
11.8
9.79
7.81
-

7-1/2
1800
24.7
21.5
13
10.7
8.55
-

7-1/2
1200
25.1
21.8
13.2
10.9
8.7
-

7-1/2
900
26.5
23
13.9
11.5
9.19
-

10
3600
29.2
25.4
15.4
12.7
10.1
-

10
1800
30.8
26.8
16.3
13.4
10.7
-

10
1200
32.2
28
16.9
14
11.2
-

10
900
35.1
30.5
18.5
15.2
12.2
-

15
3600
41.9
36.4
22
18.2
14.5
-

15
1800
45.1
39.2
23.7
19.6
15.7
-

15
1200
47.6
41.4
25
20.7
16.5
-

15
900
51.2
44.5
26.9
22.2
17.8
-

20
3600
58
50.4
30.5
25.2
20.1
-

20
1800
58.9
51.2
31
25.6
20.5
-

20
1200
60.7
52.8
31.9
26.4
21.1
-

20
900
63.1
54.9
33.2
27.4
21.9
-

25
3600
69.9
60.8
36.8
30.4
24.3
-

25
1800
74.5
64.8
39.2
32.4
25.9
-

25
1200
75.4
65.6
39.6
32.8
26.2
-

25
900
77.4
67.3
40.7
33.7
27
-

30
3600
84.8
73.7
44.4
36.8
29.4
-

30
1800
86.9
75.6
45.7
37.8
30.2
-

30
1200
90.6
78.8
47.6
39.4
31.5
-

30
900
94.1
81.8
49.5
40.9
32.7
-

40
3600
111
96.4
58.2
48.2
38.5
-

40
1800
116
101
61
50.4
40.3
-

40
1200
117
102
61.2
50.6
40.4
-

40
900
121
105
63.2
52.2
41.7
-

50
3600
138
120
72.9
60.1
48.2
-

50
1800
143
124
75.2
62.2
49.7
-

50
1200
145
126
76.2
63
50.4
-

50
900
150
130
78.5
65
52
-

60
3600
164
143
86.8
71.7
57.3
-

60
1800
171
140
90
74.5
59.4
-

60
1200
173
150
91
75
60
-

60
900
177
154
93.1
77
61.5
-

75
3600
206
179
108
89.6
71.7
-

75
1800
210
183
111
91.6
73.2
-

75
1200
212
184
112
92
73.5
-

75
900
222
193
117
96.5
77.5
-

100
3600
266
231
140
115
92.2
-

100
1800
271
236
144
118
94.8
23.6

100
1200
275
239
145
120
95.6
24.2

100
900
290
252
153
126
101
24.8

125
3600
-
292
176
146
116
-

125
1800
-
293
177
147
117
29.2

125
1200
-
298
180
149
119
29.9

125
900
-
305
186
153
122
30.9

150
3600
-
343
208
171
137
-

150
1800
-
348
210
174
139
34.8

150
1200
-
350
210
174
139
35.5

150
900
-
365
211
183
146
37

200
3600
-
452
257
226
181
-

200
1800
-
458
265
229
184
46.7

200
1200
-
460
266
230
184
47

200
900
-
482
279
241
193
49.4

250
3600
-
559
338
279
223
-

250
1800
-
568
343
284
227
57.5

250
1200
-
573
345
287
229
58.5

250
900
-
600
347
300
240
60.5

300
1800
-
678
392
339
271
69

300
1200
-
684
395
342
274
70

400
1800
-
896
518
448
358
91.8

500
1800
-
1110
642
555
444
116


NOTES: (1) 380v 50Hz

Ampere Ratings of Three Phase 60Hz AC Induction Motor
hp	Syn. Speed RPM	200V	230V	380V (1)	460V	575V	2200V
1/4	1800	1.09	0.95	0.55	0.48	0.38	-
1/4	1200	1.61	1.4	0.81	0.7	0.56	-
1/4	900	1.84	1.6	0.93	0.8	0.64	-
1/3	1800	1.37	1.19	0.69	0.6	0.48	-
1/3	1200	1.83	1.59	0.92	0.8	0.64	-
1/3	900	2.07	1.8	1.04	0.9	0.72	-
1/2	1800	1.98	1.72	0.99	0.86	0.69	-
1/2	1200	2.47	2.15	1.24	1.08	0.86	-
1/2	900	2.74	2.38	1.38	1.19	0.95	-
3/4	1800	2.83	2.46	1.42	1.23	0.98	-
3/4	1200	3.36	2.92	1.69	1.46	1.17	-
3/4	900	3.75	3.26	1.88	1.63	1.3	-
1	3600	3.22	2.8	1.7	1.4	1.12	-
1	1800	4.09	3.56	2.06	1.78	1.42	-
1	1200	4.32	3.76	2.28	1.88	1.5	-
1	900	4.95	4.3	2.6	2.15	1.72	-
1-1/2	3600	5.01	4.36	2.64	2.18	1.74	-
1-1/2	1800	5.59	4.86	2.94	2.43	1.94	-
1-1/2	1200	6.07	5.28	3.2	2.64	2.11	-
1-1/2	900	6.44	5.6	3.39	2.8	2.24	-
2	3600	6.44	5.6	3.39	2.8	2.24	-
2	1800	7.36	6.4	3.87	3.2	2.56	-
2	1200	7.87	6.84	4.14	3.42	2.74	-
2	900	9.09	7.9	4.77	3.95	3.16	-
3	3600	9.59	8.34	5.02	4.17	3.34	-
3	1800	10.8	9.4	5.7	4.7	3.76	-
3	1200	11.7	10.2	6.2	5.12	4.1	-
3	900	13.1	11.4	6.9	5.7	4.55	-
5	3600	15.5	13.5	8.2	6.76	5.41	-
5	1800	16.6	14.4	8.74	7.21	5.78	-
5	1200	18.2	15.8	9.59	7.91	6.32	-
5	900	18.3	15.9	9.6	7.92	6.33	-
7-1/2	3600	22.4	19.5	11.8	9.79	7.81	-
7-1/2	1800	24.7	21.5	13	10.7	8.55	-
7-1/2	1200	25.1	21.8	13.2	10.9	8.7	-
7-1/2	900	26.5	23	13.9	11.5	9.19	-
10	3600	29.2	25.4	15.4	12.7	10.1	-
10	1800	30.8	26.8	16.3	13.4	10.7	-
10	1200	32.2	28	16.9	14	11.2	-
10	900	35.1	30.5	18.5	15.2	12.2	-
15	3600	41.9	36.4	22	18.2	14.5	-
15	1800	45.1	39.2	23.7	19.6	15.7	-
15	1200	47.6	41.4	25	20.7	16.5	-
15	900	51.2	44.5	26.9	22.2	17.8	-
20	3600	58	50.4	30.5	25.2	20.1	-
20	1800	58.9	51.2	31	25.6	20.5	-
20	1200	60.7	52.8	31.9	26.4	21.1	-
20	900	63.1	54.9	33.2	27.4	21.9	-
25	3600	69.9	60.8	36.8	30.4	24.3	-
25	1800	74.5	64.8	39.2	32.4	25.9	-
25	1200	75.4	65.6	39.6	32.8	26.2	-
25	900	77.4	67.3	40.7	33.7	27	-
30	3600	84.8	73.7	44.4	36.8	29.4	-
30	1800	86.9	75.6	45.7	37.8	30.2	-
30	1200	90.6	78.8	47.6	39.4	31.5	-
30	900	94.1	81.8	49.5	40.9	32.7	-
40	3600	111	96.4	58.2	48.2	38.5	-
40	1800	116	101	61	50.4	40.3	-
40	1200	117	102	61.2	50.6	40.4	-
40	900	121	105	63.2	52.2	41.7	-
50	3600	138	120	72.9	60.1	48.2	-
50	1800	143	124	75.2	62.2	49.7	-
50	1200	145	126	76.2	63	50.4	-
50	900	150	130	78.5	65	52	-
60	3600	164	143	86.8	71.7	57.3	-
60	1800	171	140	90	74.5	59.4	-
60	1200	173	150	91	75	60	-
60	900	177	154	93.1	77	61.5	-
75	3600	206	179	108	89.6	71.7	-
75	1800	210	183	111	91.6	73.2	-
75	1200	212	184	112	92	73.5	-
75	900	222	193	117	96.5	77.5	-
100	3600	266	231	140	115	92.2	-
100	1800	271	236	144	118	94.8	23.6
100	1200	275	239	145	120	95.6	24.2
100	900	290	252	153	126	101	24.8
125	3600	-	292	176	146	116	-
125	1800	-	293	177	147	117	29.2
125	1200	-	298	180	149	119	29.9
125	900	-	305	186	153	122	30.9
150	3600	-	343	208	171	137	-
150	1800	-	348	210	174	139	34.8
150	1200	-	350	210	174	139	35.5
150	900	-	365	211	183	146	37
200	3600	-	452	257	226	181	-
200	1800	-	458	265	229	184	46.7
200	1200	-	460	266	230	184	47
200	900	-	482	279	241	193	49.4
250	3600	-	559	338	279	223	-
250	1800	-	568	343	284	227	57.5
250	1200	-	573	345	287	229	58.5
250	900	-	600	347	300	240	60.5
300	1800	-	678	392	339	271	69
300	1200	-	684	395	342	274	70
400	1800	-	896	518	448	358	91.8
500	1800	-	1110	642	555	444	116

Single-Phase AC Motors

Ampere Rating of AC and DC Motors

The following values of fullload currents are for motors running at usual speeds and motors with normal torque characteristics. Motors built for especially low speeds or high torques may have higher full-load currents and multispeed motors will have full-load current varying with speed, in which case the nameplate current ratings shall be used.

The voltages listed are rated motor voltages. The currents listed shall be permitted for system voltage ranges of 110 to 120 and 220 to 240V.

Full-Load Currents in Amperes, Single-Phase Alternating- Current Motors



hp
115V
200V
208V
230V


1/6
4.4
2.5
2.4
2.2

1/4
5.8
3.3
3.2
2.9

1/3
7.2
4.1
4.0
3.6

1/2
9.8
5.6
5.4
4.9

3/4
13.8
7.9
7.6
6.9

1
16
9.2
8.8
8

1-1/2
20
11.5
11
10

2
24
13.8
13.2
12

3
34
19.6
18.7
17

5
56
32.2
30.8
28

7-1/2
80
46
44
40

10
100
57.5
55
50

Full-Load Currents in Amperes, Single-Phase Alternating- Current Motors
hp	115V	200V	208V	230V
1/6	4.4	2.5	2.4	2.2
1/4	5.8	3.3	3.2	2.9
1/3	7.2	4.1	4.0	3.6
1/2	9.8	5.6	5.4	4.9
3/4	13.8	7.9	7.6	6.9
1	16	9.2	8.8	8
1-1/2	20	11.5	11	10
2	24	13.8	13.2	12
3	34	19.6	18.7	17
5	56	32.2	30.8	28
7-1/2	80	46	44	40
10	100	57.5	55	50