Hitachi SJ700-2 Series service manual Troubleshooting, Inverter trip contents,remedy,advise

2. Troubleshooting

2.1 Inverter trip contents,remedy,advise

Name	Description		Display on		Display on	Troubleshooting and corrective action
		digital operator		remote operator
	If the motor is constrained					Check whether the load has fluctuated sharply.
	or suddenly accelerated	During				(Eliminate the load fluctuation.)
	or decelerated, a high					Check for the short circuit of output
		constant-
	current will flow in the				OC.Drive	connections.
		speed
	inverter and the inverter					(Check the output cables.)
		operation
	may fail. To avoid this					Check for the ground fault.
	problem, the inverter					(Check the output cables and motor.)
	shuts off its output and	During				Check whether the inverter has decelerated the
	displays the error code	deceleration			OC.Decel	motor quickly.
	shown on the right when it					(Increase the deceleration time.)
	detects a current higher
Overcurrent						Check whether the inverter has accelerated the
	than a specified level.					motor quickly.
protection	This protective function					(Increase the acceleration time.)
	uses a DC current	During				Check whether the motor has been locked.
					OC.Accel
	detector (CT) to detect	acceleration				(Check the motor and wiring.)
	overcurrent.					Check whether the torque boost current has
	When a current as high as					been set too high.
	about 220% of the					(Reduce the boost current.)
	inverter's rated output					Check whether the DC braking force is too high.
	current is detected, the					(Reduce the braking force.)
	protective circuit operates	Others			Over.C	Check whether the current detector (CT) is
	and the inverter trips.					normal.
						(Replace or repair the CT.)
	This protective function monitors the					Check whether the motor load is too high.
	inverter output current, and shuts off the					(Reduce the load factor.)
	inverter output and displays the error code					Check whether the thermal level is appropriate.
	shown on the right when the internal					(Adjust the level appropriately.)
Overload	electronic thermal protection circuit					Note:
	detects a motor overload.					The electronic thermal protection is easily
protection	If the error occurs, the inverter will trip				Over.L	triggered when the output frequency is 5 Hz or
(*1)	according to the setting of the electronic					less. If the moment of inertia of the load is large,
	thermal function.					this protective function may operate when the
						inverter accelerates the motor and the
						acceleration may be disabled. If this problem
						occurs, increase the torque boost current or
						adjust other settings as needed.
	When the BRD operation rate exceeds					Check whether the inverter has decreased the
	the setting of "b090", this protective					motor quickly.
Braking	function shuts off the inverter output and					(Increase the deceleration time.)
	displays the error code shown on the					Check whether the operation cycle is too short.
resistor	right.				OL.BRD	(Prolong the operation cycle.)
overload						Check whether the set BRD operation rate is
protection						too low.
						(Adjust the setting to an appropriate level.)
						Note: confirm the maximum allowable capacity
						of the resistor.
	If the DC voltage across the P and N
	terminals rises too high, an inverter failure
	may result. To avoid this problem, this
	protective function shuts off the inverter					Check whether the inverter has decreased the
	output and displays the error code shown
						motor quickly.
	on the right when the DC voltage across
						(Increase the deceleration time.)
	the P and N terminals exceeds a specified				Over.V
Overvoltage						Check for a ground fault.
protection	level because of an increase in the energy					(Check the output cables and motor.)
	regenerated by the motor or the input					Check whether the motor has been rotated by
	voltage (during operation).
						the action of the load.
	The inverter will trip if the DC voltage
						(Reduce the regenerative energy.)
	across the P and N terminals exceeds
	about 400 VDC (in case of the 200 V class
	models) or about 800 VDC (in case of the
	400 V class models).
	When an internal-EEPROM is caused by					Check for the noise sources located near the
EEPROM	external noise or an abnormal					inverter.
	temperature rise, the inverter shuts off its					(Remove noise sources.)
error	output and displays the error code shown				EEPROM	Check whether the cooling efficiency has
(*2) (*3)	on the right.					deteriorated.
	Note: An EEPROM error may result in a					(Check the heat sink for clogging, and clean it.)
	CPU error.					(Replace the cooling fan.)

*1 The inverter will not accept any reset command within about 10 seconds after tripping (i.e., after the protective function operates).

*2 The inverter will not accept any reset command after an EEPROM error occurs with error code displayed. Turn off the inverter power once. If error code "E08" is displayed when the inverter power is turned on subsequently, the internal memory device may have failed or parameters may have not been stored correctly. In such cases, initialize the inverter, and then re-set the parameters.

*3 The inverter will not accept reset commands input via the RS terminal or entered by the STOP/RESET key. Therefore, turn off the inverter power.

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