Mitsubishi FR - S500 instruction manual 142

(3) Warnings

Operation Panel Indication	OL			FR-PU04	OL
Name	Stall prevention (overcurrent)
		If a current of more than 150% (* 4) of the rated
		inverter current flows in the motor, this function
	During	stops the increase in frequency until the overload
		current reduces to prevent the inverter from
	acceleration
		resulting	in	overcurrent	shut-off. When the
		overload current has reduced below 150%, this
		function increases the frequency again.
		If a current of more than 150% (* 4) of the rated
	During	inverter current flows in the motor, this function
		lowers the frequency until the overload current
	constant-
Description		reduces to prevent overcurrent shut-off. When the
	speed
		overload current has reduced below 150%, this
	operation
		function increases the frequency up to the set
		value.
		If a current of more than 150% (* 4) of the rated
		inverter current flows in the motor, this function
	During	stops the decrease in frequency until the overload
		current reduces to prevent the inverter from
	deceleration
		resulting	in	overcurrent	shut-off. When the
		overload current has reduced below 150%, this
		function decreases the frequency again.
Check point	Check the motor for use under overload.
	The acceleration/deceleration time may change.
	Increase the stall prevention operation level with Pr. 22 "stall
Corrective action	prevention operation		level", or disable		stall prevention with
	Pr. 21 "stall prevention function selection".
	Check that the torque boost (Pr. 0) setting is not higher than
	required.

*4. The stall prevention operation current can be set as desired. It is factory-set to 150%.

Operation Panel Indication	oL		FR-PU04	oL
Name	Stall prevention (overvoltage)
		If the regenerative energy of the motor increases
	During	too much to exceed the brake capability, this
Description		function stops the decrease in frequency to prevent
	deceleration
		overvoltage shut-off. As soon as the regenerative
		energy has reduced, deceleration resumes.
Check point	Check for sudden speed reduction.
Corrective action	The deceleration time may		change. Increase the deceleration
	time using Pr. 8 "deceleration time".

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