Siemens SIMATIC ET 200SP Manual page 49

Switching cycle parameters
The following table shows all the parameters that you have to consider for calculation of the
permissible switching cycle:
Parameters
Starting time
Starting
current
Motor
operation
time
Rated
operational
current
Motor OFF
time:
Switching
cycle interval
You use the switching cycle interval time to determine the permissible starting frequency per
hour as follows:
As from a starting current of 65 A in the case of the 9 A and 12 A motor starters, consider the
device protection model for calculation of the switching cycles. The following graphics show
the minimum idle time depending on the starting current:
Motor starter (3RK1308-0**00-0CP0)
Manual, 12/2016, A5E34821005002A/RS-AB/002
Description
t [s] Time during which the motor
Startup
accelerates up to its
operating speed from
standstill
I [A] Root-mean-square of the
Startup
motor current that flows
during the starting time. It is
considered as a multiple x of
the rated value of the motor
I and/or the
rated_motor
parameterized rated
operational current I
I [A] = x * I
Startup
t [s] Time in which the motor is in
Motor
operation after startup.
I [A] Root-mean-square of the
e
motor current in the
operating phase after the
starting time or the
parameterized value I
motor starter
t [s] Idle time of the motor within
Off
the switching cycle
T [s] Total of t
Off,
Conditions
The maximum is determined by the
parameterized tripping class and the
intrinsic device protection (see also
Overload protection (Page 42)).
The maximum is the permissible current
of the relevant device class. Consider
additional idle times in the case of
starting currents in excess of 65 A (see
example graphics).
(Also see: Overload protection
(Page 42) and the example graphics)
.
e
[A]
e
-
The permissible I
adjustment range of the motor starter
used and its ambient temperature (see
also: Overload protection (Page 42)).
of the
e
Consider additional idle times in the
case of starting currents in excess of
65 A (see example graphics).
t and t The maximum time is 300 s.
Motor Startup
Product overview
3.7 Functions
is determined by the
e
49