Hitachi SJ300 Series manual 228

6–4

Troubleshooting

Symptom/condition		Probable Cause		Solution
		• If using the analog input, is there	•	Check the wiring.
		current or voltage at [O] or [OI]?	• Check the potentiometer or
				signal generating device.
		• Is the load too heavy?	•	Reduce the load.
			• Heavy loads activate the
				overload restriction feature
The motor speed will not reach the				(reduces output as needed).
		• Is the inverter internally limiting the	• Check max frequency setting
target frequency (desired speed).
		output frequency?		(A004)
			• Check frequency upper limit
				setting (A061)
			• If using analog inputs, check
				their settings (A101– A104)
				or (A111–A114), or (A011–
				A014)
		• Is the load fluctuation too great?	• Increase the motor capacity
				(both inverter and motor).
The rotation is unstable.		• Is the supply voltage unstable?	• Fix power supply problem.
		• Is the problem occurring at a particular	• Change the output frequency
		frequency?		slightly, or use the jump
				frequency setting to skip the
				problem frequency.
The RPM of the motor does not		• Is the maximum frequency setting	• Verify the V/F settings match
		A004 correct?		motor specifications.
match the inverter output
		• Does the monitor function D001	• Make sure all scaling (such as
frequency setting.
		display the expected output frequency?		A011 to A014) is properly set.
A parameter	True for certain	• Is the inverter in Run Mode? Some	• Put inverter in Stop Mode
	parameters	parameters cannot be edited during		(press the Stop/reset key). Then
will not
		Run Mode.		edit the parameter.
change after
an edit	True for all	• If you’re using the [SFT] intelligent	• Change the state of the SFT
(reverts to old	parameters	input (software lock function)—is the		input, and check the B031
setting).
		[SFT] input ON?		parameter (SFT mode).

Troubleshooting and Maintenance