Mitsubishi Electronics FR-V500 instruction manual Troubleshooting Machine operates unstably

Troubleshooting

6.4.5Machine operates unstably

(1) Speed control

The machine operates unstably.

Is the acceleration/	Y
deceleration time longer
than the setting?

N

Y

Is torque insufficient?

Increase the torque restriction value, or increase the excitation

N ratio (Pr. 854).

<Refer to the Instruction Manual (detailed).>

Increase the motor and inverter capacities.

Is the load inertia large?

Y

Is the acceleration/ deceleration time extremely short?

N

Is the speed control gain too high. (Vibration/hunting)

N	Set the acceleration/
	deceleration time that matches
	the load inertia.

Y

Increase the acceleration/ deceleration time.

Y

N

Does speed fluctuation occur at low speed?

N

Perform easy gain tuning. Decrease the speed control proportional gain (Pr. 820). Increase the speed control integral time (Pr. 821).

Y

Is the carrier frequency high?

N

Is the speed control gain low?

N

Y

Decrease the carrier frequency (Pr. 72).

Y

Increase the speed control proportional gain (Pr. 820). Decrease the speed control integral time (Pr. 821).

AND PROTECTIVE FUNCTIONS

Please contact your sales representative.

	Y
Is torque insufficient?
	The possible cause is the
N	adverse effect of weak
	excitation.
	Increase the excitation ratio
	(Pr. 854). <Refer to the
	Instruction Manual (detailed).>

ERRORS

6

88