SV0436Servo alarm · CNC servo monitoring
Fanuc αi SV0436: Soft Thermal (OVC)
Also shown as: 16i/18i/21i/0i: 436
What SV0436 means
The CNC's motor thermal model (soft thermal, OVC) calculated that the servo motor is overheating from the current it has drawn.
Symptoms
Alarm on one axis after heavy cutting or many fast moves; the load meter for that axis runs high.
Is it repairable?
Often mechanical; motor or amplifier repair when current is high with no load.
Common causes
- High mechanical load (tight gibs, worn ball screw, way lube failure)
- Brake dragging
- Poor servo tuning or oscillation
- Motor or amplifier fault causing extra current
Safe checks
- 1Check the axis load meter at rest and while moving
- 2Check way lubrication
- 3Confirm the brake releases (support vertical axes first)
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the FANUC αi series Maintenance Manual.
Related Fanuc αi faults
- SV0368Serial data error (built-in)
- SV0401V ready off
- SV0433DC link undervoltage
- SV0438motor current alarm
- SV0442DC link precharge failure
- SV0443cooling fan stopped