18 monitoring of the speed system deviation (nerr), Monitoring of the speed system deviation (nerr), Monitoring functions – Lenze ECSCSxxx User Manual
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Monitoring functions
Configuring monitoring functions
Monitoring of the speed system deviation (nErr)
l
222
EDBCSXS064 EN 4.0
9.3.18
Monitoring of the speed system deviation (nErr)
Fault message
Monitoring function
System variable
Possible response
TRIP
Messa
ge
Warni
ng
FAIL−Q
SP
Off
190
nErr
Speed outside of the
tolerance window (C0576)
MCTRL_bSpeedLoopFault_b
ь
ь
ь
ь
·
· Default setting
üSetting possible
This monitoring function compares the actual speed value provided by the speed sensor
with the speed setpoint of the speed controller. If the difference between the two speed
values exceeds the tolerance window set in C0576, the nErr monitoring function responds.
ƒ
If the system deviation exceeds a certain value, this may indicate a drive problem.
The drive cannot follow the selected speed setpoint as fast as required. If the
controller generally is in working condition, mechanical blockages on the load side
or insufficient motor torque may be the cause.
Furthermore, this monitoring function can be used to additionally protect a speed sensor
operating in the speed−controlled mode. The monitoring function thus supplements the
individual encoder monitoring.
ƒ
Faults on the encoder system bring about an incorrect actual speed value. This
normally results in a system deviation on the speed controller that is greater than
that in the normal operating status.
ƒ
The tolerance margin is set via C0576.
ƒ
The response is set via C0579.
)
Note!
ƒ
Set the tolerance window (C0576) to at least twice the value of the system
deviation occurring during operation. The value can be identified by
respective tests when commissioning is effected.
ƒ
Please observe that the system deviation reaches higher values under
normal operating conditions with short ramp times.
Code
Possible settings
IMPORTANT
No.
Designation
Lenze/
{Appl.}
Selection
C0576 nErr tolerance
100
Tolerance window for the speed
system deviation referring to
n
max
100 % = lowest monitoring
sensitivity
^ 222
0
{1 %}
100
C0579 nErr response
3
Fault response − monitoring of
speed system deviation
^ 222
0
TRIP
1
Message
2
Warning
3
Off
4
FAIL−QSP