Toshiba H9 operation manual PtSt, With the Low-current Trip

LED	LCD	Description		Possible Causes
Display	Display
*OP	Overvoltage		•	ASD attempting to start into a spinning motor after a
		DC bus voltage exceeds		momentary power loss.
		specifications.	• Incoming commercial power is above the specified
				range.
			• Decel time is too short.
			• Voltage spikes at the 3-phase input; install inductive
				filter.
			•	DBR required.
			• DBR resistance value is too high.
			• DBR function is turned off.
			• Overvoltage Stall feature is turned off.
			•	System is regenerating.
			•	Load instability.
			• Disable the Ridethrough function (F302).
OT	Overtorque	Torque requirement is in excess	•	ASD is not correctly matched to the application.
		of the setting of F616 or F617	• F616 or F617 setting is too low.
		for a time longer than the setting
		of F618.	•	Obstructed load.
*POFF	Control		•	Defective Control board.
	Undervoltage	Undervoltage condition at the 5,	• Excessive load on power supply.
		15, or the 24 VDC supply.
			•	Low input voltage.
PtSt	Reference Point	Two speed-reference frequency	•	Two speed reference frequency setpoints are too close to
		setpoint values are too close to		each other (increase the difference).
		each other.
UC	Undercurrent	With the Low-current Trip	this function sets the low-current trip threshold
		(F610) parameter enabled, the
		output current of the ASD is
		below the level defined at F611
		and remains there for a time
		longer than the setting of F612.
* Reset ignored if active.

H9 ASD Installation and Operation Manual 249