SRVO-046: OVC alarm (overcurrent RMS)
The running average (RMS) of motor current exceeded the protection limit - the servo system's thermal-protection math saying the motor is being worked toward damage.
What it means
The running average (RMS) of motor current exceeded the protection limit - the servo system's thermal-protection math saying the motor is being worked toward damage. Different from HCAL's instantaneous spike: OVC is sustained overwork. Power-cycle to clear.
Common causes
Ranked by what technicians most often find, most likely first.
- Overload - payload or duty beyond rating.
- Sustained very slow motion increasing effective friction (a FANUC-specific quirk worth knowing).
- External force loading the robot.
- Brake dragging - not fully releasing (including mis-set brake number on aux axes, aux brake fuse).
- Low supply voltage forcing higher current.
- Hardware: motor, amplifier, cabling.
How to fix it
- The running average of motor current exceeded the protection limit, which usually points at the robot being worked too hard rather than a component failure. The safe, non-invasive checks first: confirm payload and duty are within rating and reduce if over; if the program runs long stretches of very slow motion, breaking it up with a faster move helps (FANUC notes sustained creep-speed motion raises effective current); remove any external force loading the robot, or re-teach a binding position. Beyond those, a dragging brake, low supply voltage, or a motor/amplifier/cable fault requires a qualified technician working per the maintenance manual, since it involves servo power circuits. Power-cycle to clear.
Quick facts
- Category
- Servo
- Affected series
- R-30iB; R-30iB Mate; R-30iB Plus; R-30iB Mate Plus
- Alarm family
- SRVO