SIEMENS
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Siemens MD 50.8 · 2017
Configuring guide
Configuring a three-phase motor
2
■
Determining the duty type
The power ratings for continuous duty with constant load (duty
type S1) are listed in the power tables. The motor power ratings
can be converted to the lower duty cycle using the correspond-
ing
k
DC
factors for S1, S2, and S3 duty types.
For increased power, you should note that the breakdown torque
ratio must not fall below 1.6. This same regulation applies when
differentiating between the following groups of duty types.
Duty types according to EN 60034-1 (IEC 60034-1)
Code
Description
Unit
P
DC
Power for the new duty cycle
kW
P
rated
Rated motor power
kW
k
DC
Factor for increased power
-
P
DC
P
rated
k
DC
=
Duty type
Description
Information required
Factor for
increased power
k
DC
S1
Continuous duty
Cyclic duration factor = 100 %
-
-
-
S2
Constant load for a brief time,
e.g. S2 - 30 min
Load duration
60 min
1.10
30 min
1.20
10 min
1.40
S3
Intermittent periodic duty,
where starting has no significant
influence (cyclic operation),
e.g. S3 - 40 %
Cyclic duration factor in % (referred to 10 min)
60 %
1.10
40 %
1.15
25 %
1.30
15 %
1.40
S4 … S10
Intermittent periodic duty with
the influence of starting
Cyclic duration factor in % (referred to 10 min), starts per
hour, load torque and moment of inertia
The duty type and motor power can be determined if the
number of starting operations per hour, starting time, load
duration, type of braking, braking time, idle time, cycle
time, standstill time, and required power are specified.
On request
-
© Siemens AG 2017