Parameter Operation Mode 571 = 1,11, 101 or 111
In multiple motor operation, it is assumed that each data set is assigned to a corre-
sponding motor. For this, one motor and one motor protection switch are assigned to
each data set. In this operation mode, the rated values of t
he active data set are
monitored. The current output current of the frequency inverter is only taken into
account in the motor protection switch activated by the data set. In the motor pro-
tection switches of the other data sets, zero current is expected, w
ith the result that
the thermal decay functions are taken into account. In combination with the data set
change-
over, the function of the motor protection switch is similar to that of motors
connected alternately to the mains with their own protection switches.
In operation modes 101 and 111
additionally the integrated current over the time is
stored when the device is switched odd and set to the stored value when switched on
again.
Parameter Operation Mode 571 = 2, 22, 102 or 122
In single motor operation, only one motor protection switch, which monitors the out-
put current of the frequency inverter, is active. In the case of a data set change-
only the switch-off limits derived from the rated machine parameters are changed
over. Accumulated thermal values are used after the change-
over as well. In the case
of the data set change-over, please ensure that the machine data are stated identi-
cally for all data sets. In combination with the data set change-over, the functio
n of
the motor protection switch is similar to that of motors connected alternately to the
mains with one common protection switch.
In operation modes 102 and 122
additionally the integrated current over the time is
stored when the device is switched odd a
nd set to the stored value when switched on
again.
Parameter Operation Mode 571 = 101, 102, 111 or 122.
The internal state of the motor protection switch is latched reset stable. These set-
tings are to be used when regularly short mains interruptions occur. This way the
motor protection is considered correctly for short mains failures or short shut downs
of the application.
In settings 101, 102, 111 and 112 of
Operation Mode 571 the same
values should be
set in all data sets.
Motor protection, in particular self-ventilation motors, is improved via the Frequency
limit 572
which can be set as a percentage of the rated frequency. The measured
output current in operating points below the frequency limit is assessed by a factor of
2 higher in the calculation of the trigger characteristic.
Parameter Settings
No.
Description Min. Max. Fact. sett.
572 Frequency Limit 0 % 300 % 0 %
Digital signals indicate the triggering of the function “Motor Protection Switch”.
180 -
Warning Motor
Protection Switch
1)
Triggering of the function “Motor Protection Switch”
according to
Operation Mode 571 is signalized.
14 -
2)
1)
For linking with inverter functions
06/13 Operating Instructions ACU 247