Hitachi J300U Series instruction manual Protection Functions

8. PROTECTION FUNCTIONS

The J300 series inverters are equipped with protection functions against overcurrent, overvoltage, and undervoltage which protect the inverter. If the protection functions are engaged, the output is shut down, motor runs free and holds that condition until it is reset.

Description	Contents						Display
Over current	A currrent due to the alternating current CT between the power module					Constant
protection	and output terminal {U(T1), V(T2), W(T3)} is detected.					speed
	When the motor is restricted or decelerated suddenly, a large current
	flows through the inverter and causes a fault. Therefore, when an					Dec.
	abnormal current is detected by the alternating current CT and it exceeds
	a specified value, the output is cut off. (An abnormal current is also					Acc.
	detected in the power module. Refer to	,	,	, and	.)
Overload	When a motor overload is detected by the electronic thermal function, the output
protection
	of the inverter is cut off.
(NOTE 1)
Braking	When the braking time exceeds the satting by		braking duty factor, an
resistor overload	overvoltage the output of the inverter is cut off.
Overvoltage	When the converter voltage exceeds a certain level due to regenerative energy from
protection	the motor, this protection function engages, and the output of inverter is cut off.
EEPROM error	When the memory built in has problems due to noise or excessive temperature rise,
(NOTE 2)	this protective function engages, and the output of inverter is cut off.
Undervoltage	A decrease of the input voltage of an inverter results in improper function of the
	control circuit. It also generates motor heat and causes low torque. Output is cut off
protection
	when the input voltage goes down to less than 150-160V/300-320V(200/400Vclass).
CT error	Abnormality on built-in CT and the output of the inverter is cut off.
CPU error	Malfunction or abnormality on built-in CPU and the output of the inverter is cut
	off.
External trip	An abnormality signal from external equipment cuts off the output of the inverter.
	(When external trip function is selected)
USP error	It indicates an error when power is turned on while the inverter is being run.
	(When USP function is selected)
Ground fault	The inverter is protected by detection of ground faults between the inverter output
protection	and the motor upon power on. There may be the possibility of power module failure.
	When the input voltage is higher than the specified value, it is detected 100 seconds
	after power is turned on and the output is cut off. However, when a voltage higher
Input overvoltage	than approx. 250 to 270 V (200V class),
	500 to 530 V (400 V class) is inputted, it is higher than the rated value of the part
	in use, so that the part may not be protected and damaged.
Instantaneous	When an instantaneous power failure for more than 15 ms occurs, the output is cut
	off. When the instantaneous power failure time is long, the fault signal is released.
power failure
	Note that when restart is selected, the equipment restarts when the running
(NOTE 4)
	command remains.

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