Commissioning The Mains Failure Control - Lenze i55AE125B Manual

11.15.4

Commissioning the mains failure control

Commissioning should be executed with motors without load:
1. Let the motor rotate with a rated frequency of 100 %.
2. Disable the inverter and measure the time until the motor has reached standstill.
The time can be measured with a stop watch or similar.
•
If a motor encoder is connected to the inverter and set as feedback system for the
•
motor control, this signal can be output at the analog output and measured with an
oscilloscope.
3. Set the acceleration time for the voltage setpoint in
of the time measured before.
4. Set the switch-off time n
Fine adjustment of the mains failure control
For the fine adjustment, you must repeat the following points several times:
1. An end frequency as low as possible should be reached before the inverter reaches the
error threshold for undervoltage:
Increase the proportional gain of the DC-bus voltage controller in
•
(P721.03).
Reduce the reset time of the DC-bus voltage controller in
•
2. If, during the mains failure control, monitoring for overvoltage in the DC bus is triggered:
Increase the reset time again in
•
anymore.
If required, additionally reduce the voltage setpoint in
•
which the DC-bus voltage is to be controlled.
3. Increasing the delay time or reducing the braking torque is only possible to a limited
extent:
Increasing the acceleration time in
•
torque and simultaneously increases the deceleration time.
Increasing the reset time of the DC-bus voltage controller in
•
reduces the braking torque and simultaneously increases the deceleration time. If the
reset time is too high, the inverter reaches the error threshold for undervoltage before
standstill is reached. From this point on, the motor is not guided anymore.
Signal flow - DC-bus voltage controller
Current DC-bus voltage
①
Internally generated frequency setpoint that is transferred to the motor control in case of an active mains failure control.
②
0x2D66:006 (P721.06)
0x2D66:007 (P721.07) to the time measured before.
0x2D66:004 (P721.04)
0x2D66:006 (P721.06)
0x2D66:005
0x2D66:006
Additional functions
Commissioning the mains failure control
to approx. 1/10
0x2D66:003
0x2D66:004 (P721.04).
until monitoring is not triggered
0x2D66:005 (P721.05) onto
reduces the initial braking
0x2D66:004 (P721.04)
0x2D66:003
0x2D66:004
Mains failure control
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