Motor Load Monitoring (I2Xt) - Lenze 8400 StateLine C Reference Manual

8400 StateLine C | Reference manual
Motor control (MCTRL)
Monitoring
5.12.2

Motor load monitoring (I2xt)

The Inverter Drives 8400 are provided with a simple, sensorless, thermal I
monitoring of self-ventilated standard motors which is based on a mathematical model.
C00066

 If the calculated motor load reaches the motor load setting (C00120):
– The error response set in
– The "OC6: I2xt motor
– The bMctrlI2xtOverload status output of the
set to TRUE.
 A setting of

Stop!
The I
utilisation calculated in the thermal motor model is lost after mains switching,
for instance the following operating states cannot be measured correctly:
• Restarting (after mains switching) of a motor that is already very hot.
• Change of the cooling conditions (e.g. cooling air flow interrupted or too
warm).
A full motor protection requires additional measures as e.g. the evaluation of
temperature sensors that are located directly in the winding or the use of
thermal contacts.
Adjustment of the motor utilisation meter
The motor utilisation meter for indicating the motor load in
the apparent motor current (C00054) is greater than the motor overload setting (C00120).
C00120 is to be set as follows:
C00120
 If you reduce
will already be counted up before the rated overload threshold is reached.
 If you increase
will not be counted up until the rated overload threshold is reached.
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displays the calculated motor load in [%].
C00606
overload" error message will be entered into the logbook.
C00606 = "0: No Reaction" deactivates the monitoring.
2
xt motor monitoring does not present full motor protection! As the motor
I : Rated motor current (see nameplate of motor)
I r
r
I : Rated controller current at a switching frequency of f = 8 kHz
---- - 100%
⋅
N
=
I
N
C00120 starting from the calculated value, the motor utilisation meter
C00120 starting from the calculated value, the motor utilisation meter
L
will be carried out (Lenze setting: "Warning").
LS_DeviceMonitor
C00066
Firmware ≤ 11.00 - DMS 8.0 EN - 10/2011
2
xt motor
system block will be
begins to count when