Setting The Smoothing Time For Temperature Channels - Siemens SINAMICS S120 Function Manual

If the evaluation of the temperature actual value from p4105[0...11] has exceeded the fault
threshold set in p4102[0...23], then the corresponding fault is immediately activated.
Using p4118[0...11], a hysteresis for p4102[0...23] can be set for each channel.
Using p4119[0...11], a filter can be activated to smooth the temperature signal for each
channel.
The time constant of the filter depends on the number of active temperature channels and
can be read in r4120.
Failure of a sensor
Using parameter p4117[0...2], the response to the failure of a temperature sensor can be set
within a group:
● p4117 = 0 is set. The failed sensor is not taken into account.
● p4117 = 1 is set. The group outputs the value -300 °C to the outputs for the maximum
value, minimum value and the mean value.
9.5.7.5

Setting the smoothing time for temperature channels

For long or unshielded temperature cables, interference can cause the TM150 to respond
and incorrectly shutdown the drive. To avoid this, a smoothing time can be set for every
temperature channel in TM150 for the respective temperature signal.
Setting the smoothing time
The smoothing is realized using a 1st order lowpass filter. The effective smoothing time
constant depends on the number of simultaneously active temperature channels, and is
indicated in parameter r4120 [0...11].
The smoothing time constant to be set is calculated using the following formula:
Smoothing time constant (p4122) ≥ 2 · active number of channels · 50 ms
Procedure:
1. Open the inputs/outputs of the TM150 component in the STARTER commissioning tool
("Drive unit xy > Input/output component > TM150_component > Inputs/outputs").
2. Select the desired temperature sensor (e.g. sensor 5) using the tab.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Monitoring functions and protective functions
9.5 Thermal motor protection
659