FANUC CNC Troubleshooting

SV023 SV OVERLOAD
Item	Cause of trouble	Check points	Countermeasure
1	(analysis)	Check if OVERLOADED lamp lights When turning on NC power supply.	Connection/setting failure. Proceed to item 6 or 7.
		Check to see if radiation fins of servo amplifier.	Proceed to item 2.
		Check thermostat of regenerative discharge unit functions	Proceed to item 5
		Check thermostat of AC servo motor functions.	Proceed to item 2
2	Overload of motor	Measure the motor current. The continuous rated current is as specified below: Motor 4-0 …0.93A 5…6.8A 3-0 …0.93A 10…11A 2-0… 3A 20…20A 1-0… 2.9A 30…22A 0….4.6A 30R…29A	Reduce the cutting condition. If the continuous rated current exceeds the value during idle feed. Adjust the machine tool
3	Excessive regenerative energy	1) Excessive acceleration/deceleration frequency.	Reduce the acceleration/deceleration frequency by inserting a pause time
		2) Counter balance on machine tool side	Correct the counter balance
4	Wiring failure	Check to see if the following wiring is correct. * NC (CV21 - ) - Servo amplifier (CN1) * Regenerative discharge unit - Servo amplifier (CN2) * AC Servo motor - Servo amplifier (CN5)	Correct wiring
5	Setting failure on servo amplifier PCB	Check to see if setting pin S1 is set as specified.	Reset pin S20 or S1, as specified.
SV001 MOTOR OVERLOAD
Item	Cause of trouble	Check points	Countermeasure
1	Pulse coder feed back signal is not sent	Check the feedback cable	Reconnect the feedback cable
2	Motor current exceeds rated current	Check motor current	Change the cutting conditions.
SV003 EXCESS CURRENT IN SERVO (HCAL alarm is indicated)
Item	Cause of trouble	Check points	Countermeasure
1	Incorrect connect-ion of motor line	HC alarm does not occur when turning on the power supply after disconnecting the motor power line. (Since the gravity axis may drop, support it or disconnect the drive cable of gravity axis brake) .	Reconnect the motor power line correctly. If the motor power line is checked while disconnected, set terminal S10 setting to L side, or TG alarm occurs.
2	Transistor module is defective.	Check if HC alarm occurs when turning on the power supply after disconnecting the power line according to item 1. Turn off the power supply, remove PCB, and observe the resistance between terminals of the transistor module with a circuit tester	Replace transistor module. Check resistance between C1-E1 and C2; also between E1 and C2-E2 Check Resistance between C1-E1 and also between C2-E2
3	Internal shortcircuit failure of the motor winding	Check motor windings for normal insulation	Replace the motor
4	PCB is defective	PCB is defective if HC alarm occurs when there is no defect in items 1, 2, or 3.	Replace the PCB
SV004 EXCESS VOLTAGE IN SERVO (HVAL alarm is indicated)
Item	Cause of trouble	Check points	Countermeasure
1	Input AC power voltage is higher than specified	Check to see if the servo transformer taps are properly connected.	Repair the tap connection.
2	Servo motor is defective.	Check to see if the insulation resistance is normal between the motor armature (power line) and the body	Replace the motor.
3	Load is excessively motionless		Increase the acceleration/deceleration tome constant.
4	PCB is defective	PCB is defective if HV alarm occurs when there is no defect in items 1, 2, or 3.	Replace the PCB
SV005 EXCESS DISCHARGE CURRENT (DCAL alarm is indicated)
Item	Cause of trouble	Check points	Countermeasure
1	Regenerative transistor Q1 is defective or PCB is defective	DC alarm occurs immediately after power is turned on	Replace the transistor Q1 or replace PCB
2	PCB setting is incorrect.	Setting pin S2 is set to L side, although a separate regenerative discharge unit is used	Set S2 correctly.
3	The acceleration/ deceleration rate frequency is too high	Check whether the positioning frequency at rapid traverse speed exceeds 1 to 2 times per second. Check that the alarm does not occur when the rate is decreased.	Use a dwell period and decrease the acceleration/ deceleration rate