TL;DR
A servo overload alarm on the R-2000iC is either excessive payload, a collision detection threshold too sensitive for the application, or a mechanical fault in the affected joint. Start with payload verification.
What you might see
- SRVO-003 or axis overload alarm on controller
- robot stops mid-cycle
- one joint runs hot to the touch
- overload triggers at a specific program point
Likely causes
Payload exceeding the FANUC R-2000iC rated capacity for the arm pose in use
Collision detection sensitivity set too high for the application speed and load
Mechanical binding or increased friction in the joint from worn bearings or lubrication failure
Amplifier (servo drive) fault causing incorrect current output to the motor
Required tools
- FANUC R-30iB controller access (alarm and payload menus)
- IR thermometer
- FANUC-specified joint grease and grease gun
- LOTO kit
- FANUC R-2000iC Maintenance Manual
Safety first
- Never enter the robot work envelope while the robot is in automatic mode. The R-2000iC is a high-force robot with a rated payload of 165 kg or higher depending on variant.
- Use the FANUC deadman switch and restricted speed mode (T1 mode) for all manual jogging inside the safety fence.
- Lock out the controller main power before inspecting or lubricating any joint. The gravity-loaded J2 and J3 axes can move if the brakes are not engaged.
Procedure
- 1
Note the alarm code and the axis number from the FANUC controller. SRVO-023 is overload; SRVO-018 is an amplifier fault. The specific code narrows the cause.[1]
- 2
Verify the current tool and payload settings in the FANUC controller match the actual end-effector weight, center of gravity, and inertia. Incorrect payload settings underestimate the torque demand on the servo.[1]
- 3
Review the collision detection sensitivity setting. If it was recently increased, restore the previous setting and test.
- 4
Jog the affected axis slowly in manual mode. Listen for roughness or binding. Abnormal resistance at any angle indicates a mechanical problem in the joint.
- 5
Check the joint temperature with an IR thermometer. A joint that is significantly hotter than adjacent joints under the same duty cycle confirms friction or lubrication failure.
- 6
Check the grease type and quantity in the joint gearbox. Follow FANUC R-2000iC lubrication specifications for the affected joint.[1]
- 7
If an SRVO-018 amplifier fault is present alongside the overload, check the servo amplifier LED status on the control cabinet and review the FANUC amplifier diagnostics.
- 8
If mechanical binding persists after lubrication, schedule a joint inspection with a FANUC-certified technician. Do not increase the overload parameter to mask a mechanical problem.
Sources
FANUC R-2000iC Robotic Arm Maintenance Manual, FANUC
FANUC R-2000iC Robot Maintenance Manual, servo system alarms, payload configuration, and joint lubrication specifications (general)
View source
More guides for FANUC R-2000iC
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How to fix end-effector misalignment on a FANUC R-2000iC robot
End-effector misalignment on the R-2000iC is almost always TCP calibration drift from tool wear or a tool mounting shift. Verify tool geometry against the defined TCP before touching up program points.
How to diagnose erratic motion on a FANUC R-2000iC industrial robot
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How to diagnose joint noise on a FANUC R-2000iC industrial robot
Joint noise on the R-2000iC points to worn harmonic drive bearings or insufficient lubrication. Check grease interval compliance first before opening any joint.
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