Lenze i950 Series, Manual, Page: 288 / 500

13.9 Motor protection
Many monitoring functions integrated in the inverter can detect errors and thus protect the
device or motor from being destroyed or overloaded.
13.9.1 Motor overload monitoring (i²*t)
This function monitors the thermal utilisation of the motor, taking the motor currents recor-
ded and a mathematical model as a basis.
DANGER!
Fire hazard by overheating of the motor.
Possible consequences: Death or severe injuries
▶
Since the motor utilisation calculated in the thermal model gets lost after mains switching,
the following operating states cannot be determined correctly: 1.) Restarting (after mains
switching) of a motor that is already very hot and 2.) Change of the cooling conditions (e.g.
cooling air flow interrupted or too warm).
▶
To achieve full motor protection, an additional temperature monitoring function with a sep-
arate evaluation must be installed.
▶
When actuating motors that are equipped with PTC thermistors or thermal contacts, always
activate the PTC input.
Motor overload monitoring is important for motors without thermal sensor.
Details
During the calculation of the parameters
0x2D4D:001 ... 0x2D4D:008 , the speed dependence
of the permissible motor load and thus of the permissible current (difference between the
standstill current and rated current is taken into consideration.
In case of permanent overload and excess of the warning threshold set in parameter
0x2D4E ,
a warning is output in order that the higher-level Controller is still able to respond and reduce
the motor load or interrupt the operation.
The calculated thermal motor utilisation is displayed in parameter .
Parameter
Address Name / setting range / [default setting] Info
0x2D4F Motor utilisation (i²*t)
•
Read only: x %
Display of the current thermal motor utilisation.
0x2D4E Motor utilisation (i²xt) - warning threshold
0 ... [100] ... 250 % Setting of the warning threshold for motor overload monitoring.
0x2D50:001 Motor utilisation (i²xt) - monitoring: Error response For displaying the motor utilisation error response (I²xt).
Associated error code:
•
9041 | 0x2351 - RANLI_CIMES_1000_20892
0 Keine Reaktion
1 Fehler > CiA402
Configuring the motor control
Motor protection
Motor overload monitoring (i²*t)
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