Thermal motor monitoring
10
Function library
10.14
10.14.1
L
10.14-1
EDS82EV903-1.0-11/2002
10.14 Thermal motor monitoring
10.14.1 I
2
t monitoring
With I
2
t monitoring, self-ventilated three-phase AC motors can be thermally
monitored without using sensor.
(
((
( Stop!
l I
2
t monitoring does not fully protect the motor since the
calculated motor temperature is reset after every mains
disconnection!
l After renewed mains connection the connected motor can be
overheated, if
– it is already hot and is still overloaded.
– the cooling air supply is interrupted.
– the air is too hot.
l Full motor protection can be achieved by using a PTC
thermistor or thermostat in the motor.
(¶ 10.14-3)
Codes for parameter setting
Code Possible settings IMPORTANT
No. Name Lenze Selection
C0120 I
2
tswitch-off 0 0
= not active
{1 %} 200 Reference: Apparent mot o r current (C0054)
Ref. to active motor current (C0056)
possible, see C0310
^
10.14-1
Description