low-voltage

2
Squirrel-cage motors
Technical information
Electrical features
■ Efficiency, power factor, and rated torque
Efficiency and
power factor
The efficiency h and power factor
cos j values for each rated
output are listed in the selection
tables in the individual sections
of this catalogue.
For eff1 and eff2 motors, the 3 / 4
load efficiency is also indicated.
The part-load values stated in
the table opposite are averages;
precise values can be provided
on request.
Part-load efficiency % at
1/4
of full load
1/2 3/4 4/4 5/4
93
92
90
89
88
87
86
85
84
80
79
78
76
74
72
70
68
66
64
62
60
58
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
96
95
93.5
92.5
91.5
91
90
89
88
87
86
85
84
83
82
81
80
79
77
75.5
74
73
72
71
70
68
67
66
65
64
62
61
60
59
57
56
55
54
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79.5
78.5
77.5
76
75
74
73
72
71
70
69
67.5
66.5
65
64
63
62
60.5
59.5
58.5
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
96.5
95.5
94.5
93.5
92.5
91.5
90
89
88
87
86
85
83.5
82.5
81.5
80.5
79.5
78.5
77.5
76.5
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60.5
59.5
58.5
Part-load power factor at
1/4
of full load
1/2 3/4 4/4 5/4
0.70
0.65
0.63
0.61
0.57
0.53
0.51
0.49
0.47
0.45
0.43
0.41
0.40
0.38
0.36
0.34
0.32
0.30
0.29
0.28
0.27
0.26
0.86
0.85
0.83
0.80
0.78
0.76
0.75
0.73
0.71
0.69
0.67
0.66
0.65
0.63
0.61
0.59
0.58
0.56
0.55
0.54
0.52
0.50
0.90
0.89
0.88
0.86
0.85
0.84
0.83
0.81
0.80
0.79
0.77
0.76
0.75
0.74
0.72
0.71
0.70
0.69
0.68
0.67
0.63
0.62
0.92
0.91
0.90
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.80
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
0.92
0.91
0.90
0.89
0.88
0.87
0.86
0.86
0.85
0.84
0.83
0.82
0.81
0.80
0.80
0.79
0.78
0.78
0.77
0.77
0.76
0.76
Rated torque
The rated torque in Nm delivered
at the motor shaft is
9.55¸P
¸1000
M
n
P Rated output in kW
n Speed in rpm
■If the voltage deviates from its
nominal value within the allowed
limits, the locked-rotor
torque, the pull-up torque, and
the breakdown torque vary
with the approximate square
of the value, while the lockedrotor
current varies approximately
linearly.
The normal practice is to start
squirrel-cage motors directly
on-line. The torque class indicates
that with direct-on-line
starting – even if there is –5%
undervoltage – it is possible to
start up the motor against a load
torque of
up to
160% for CL 16
130% for CL 13
100% for CL 10
70% for CL 7
50% for CL 5
of the rated torque.
The individual torque characteristics
are available in the SD
configurator. In addition, it is
possible to perform calculations
with the supplied start-up program.
For type 1MA motors
In the case of the standard design
for T1/T2 and T3 and different
rated outputs, the torque
class specified for the higher
output applies.
In the case of squirrel-cage motors,
the locked-rotor torque and
the breakdown torque are listed
in the selection tables as multiples
of the rated torque.
2/16
Siemens M 11 · 2003/2004