FANUC Alarm SRVO-046 — SERVO OVC alarm
Error- Hardware
- motor and load
- Controllers
- R-J3iB / R-30iA / R-30iB
- FANUC class
- SERVO2
Manufacturer wording — SERVO OVC alarm (Group:%d Axis:%d)
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC SRVO-046 (“SERVO OVC alarm”): This alarm is issued to protect the motor when there is a danger of thermal destruction when the root-mean-square current value, calculated internally by the servo system, exceeds the maximum permissible value. First check: 1. Check the operating conditions of the robot. Likely part: Servo amplifier (Servo amplifier).
Updated 2026-10-22 · LogrobotLM reference
Description
This alarm is issued to protect the motor when there is a danger of thermal destruction when the root-mean-square current value, calculated internally by the servo system, exceeds the maximum permissible value.
Remedy
1. Check the operating conditions of the robot. If the robot's ratings, such as the rated duty cycle and load, are exceeded, modify the use of the robot such that the rated values are not exceeded. 2. Check each interphase voltage of the three-phase voltage (200 VAC) applied to the servo amplifier connector CRR38A, which is 3-phase, and connector CRR39, which is singlephase. If the applied voltage is found to be 170 VAC or less, check the input power supply voltage. 3. Replace the servo amplifier. 4. If this does not clear the alarm, verify that all connectors are securely connected. 5. Replace the motor.
Field diagnosis
The RMS current calculated for the axis has exceeded the limit that protects the motor and amplifier from overheating: overload, external force, brake not releasing, low mains voltage or incorrectly entered payload.
What to check
- Check the cycle rate and load against the rated duty; look for an external force (jammed tool, taut cable); check the brake cable and connector; measure the supply voltage; enter the payload correctly (mass, center of gravity, inertia).
- Note: A dragging brake can be recognized by an OVC on a single axis, always the same one, when cold.
Part to check / replace
FANUC SRVO-046 points to the hardware below — start here before ordering.
Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.
Related codes
Same hardware involved
Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →