Munters HCUw, Эксплуатация и техническое обслуживание

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57
3G3JV Maintenance Operations
Chapter7
7
7-2-9 Mechanical Vibration
„
Mechanical system makes unusual noise.
•
Resonance between the characteristic frequency of the mechanical system and the carrier
frequency.
There may be resonance between the characteristic frequency of the mechanical system and
the carrier frequency. If the motor is running with no problems and the machinery system is
vibrating with a high-pitched whine, it may indicate that this is occurring. To prevent this type
of resonance, adjust the carrier frequency value in n46.
•
Resonance between the characteristic frequency of a machine and the output frequency of the
Inverter.
There may be resonance between the characteristic frequency of a machine and the output
frequency of the Inverter. To prevent this from occurring, use the frequency jump function
with the constants set in n49 through n51 to change the output frequency or install vibration-
proof rubber on the motor base to prevent the resonance of the mechanical system.
„
Vibration and hunting are occurring.
•
Influence by the slip compensation function.
The slip compensation function of the Inverter may influence the characteristic frequency of
the mechanical system to cause vibration or hunting. In that case, increase the time constant in
n67 for slip compensation. The larger this time constant is, however, the slower the response
speed of the slip compensation function will be.
„
Motor vibrates excessively and does not rotate normally.
•
Motor Phase Interruption
If one or two of the three phases of the motor are open, the motor will vibrate excessively and
will not rotate. Check that the motor is wired correctly without any disconnection. The same
phenomenon will occur if the output transistor of the Inverter is open and damaged. Check
the balance of the
Inverter’s
output voltage as well.
7-2-10 Motor Rotates
after
Output of Inverter is Turned Off
•
Insufficient
DC Control
If the motor continues operating at low speed, without completely stopping, and
after
a
deceleration stop has been executed, it means that the DC braking is not decelerating
enough.
In such cases, adjust the DC control as described below.
•
Increase the parameter in n52 for DC control current.
•
Increase the parameter in n53 for interruption DC control time.
7-2-11 Detects OV when Motor Starts and Motor Stalls
•
Insufficient
DC control at startup
Generation of OV and stalling can occur if the motor is turning when it is started.
This can be prevented by slowing the rotation of the motor by DC braking before starting the
motor. Increase the parameter in n54 for startup DC control time.