Siemens SIMATIC EM 148-FC, Manual

Page: 44 / 76

Functions and Technical Specifications
4-10
EM 148-FC Frequency Converter
A5E00065321-03
Thermistor monitoring of motor
This parameter defines how the motor temperature is monitored.
Thermistor monitoring of motor Disable:
The motor temperature is obtained by calculation by means of the I
2
t
procedure. If a thermistor is connected, it has no effect.
Thermistor monitoring of motor Enable:
A thermistor must be connected and is evaluated. A calculation is not carried
out.
Note
If the thermistor is not being used by the motor, you can use it to monitor the
motor line:
1. In the motor terminal box, bridge the thermistor cables of the supply line.
2. Enable the Thermistor monitoring of the motor parameter.
3. Evaluate the diagnosis (Actuator error).
Pulse frequency
If low-noise operation is not necessarily required, the losses in the frequency
converter and radio interference emissions can be reduced by means of a lower
pulse frequency of the output voltage.
Frequency suppression
Mechanical resonances can be avoided with this parameter. Setpoint values within
the range of the frequency specified here
±
2 Hz are not tolerated. The following
are used instead as the substitute setpoint value:
If f
suppress
– 2 Hz
≤
f
setpoint
< f
suppress
:
f
substitute
= f
suppress
– 2 Hz
If f
suppress
≤
f
setpoint
≤
f
suppress
+ 2 Hz:
f
substitute
= f
suppress
+ 2 Hz
It is possible to pass through this frequency range without hindrance during
acceleration and deceleration.
If 0 Hz is specified here, frequency suppression has no effect.
Inching frequency
Inching Mode (see Section 4.3) turns the motor in small increments at the motor
frequency set here.