What the SRVO-046 alarm means

The average current over a period exceeded the rating - the axis has been working too hard for too long. This is a high-frequency ticket for our FANUC repair team, and on R-30iA / R-30iB / R-30iB Plus systems one inspection usually identifies the fault.

Most common causes

  • Payload/inertia settings lower than the real tooling
  • Mechanical binding or degraded reducer increasing friction
  • Duty cycle too aggressive (speed/accel too high for the load)
  • Brake partially dragging
Field note: The top-listed cause has the highest hit rate, so checking it first narrows things down fast.

Step-by-step field fix

  1. Correct payload and inertia settings first - free and often the fix
  2. Reduce speed/acceleration on heavy moves
  3. Feel the motor/gearbox temperature - local overheating indicates mechanical load
  4. Check brake release with servo on: axis should move freely when pushed (in a safe test)
Safety first: For FANUC srvo-046, servo circuits are live and motor shafts and reducers rotate: measuring current waveforms or winding resistance means contact with live or moving parts. On site you may look at after confirming power-off the first step yourself: Correct payload and inertia settings first - free and often the fix. Beyond that it is live servo circuits and rotating parts work - leave it to a professional.

How we diagnose servo alarms on site

FANUC srvo-046 belongs to the servo & drive family. On FANUC srvo-046 the failing stage is alpha-i / beta-i servo amplifiers with PSM supply modules and SVM servo modules (SPM where spindles fit) on the R-30iB Plus / R-30iB Mate Plus / R-30iA - the servo closed loop: current/velocity/position loop misbehaviour, motor-drive matching and load identification. We start reading FANUC srvo-046 at the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code.

The chain involved in FANUC srvo-046 runs: target -> position loop -> velocity loop -> current loop -> power output -> motor -> feedback -> loop compare.

Payload/inertia settings lower than the real tooling on FANUC srvo-046 needs two causes separated first: A servo motor whose brake never fully opens runs overloaded and reports overcurrent or overload - it looks like a dead drive. Insufficient coil supply, a sticking lining or a wrong gap all produce this running-on-brake condition. The other case is turn-to-turn winding shorts: one phase reads high current and the motor runs hot. We measure brake coil supply and actuation current first, then winding resistance balance across the three phases; only when both are wrong do we talk about replacing the motor.

Field notes on this page cover FANUC srvo-046 (OVC Alarm - Overcurrent (Average)); written by the Henghuan repair team, updated 2026-10-01.

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Related Servo & Drive alarms

SRVO-021 — SRDY Off (Group / Axis) SRVO-023 — Stop Error Excess (Group / Axis) SRVO-024 — Move Error Excess (Group / Axis) SRVO-043 — DCAL Alarm - Discharge Alarm SRVO-044 — HVAL Alarm - High Voltage SRVO-045 — HCAL Alarm - High Current
Same family: this code belongs to the Servo & drive alarms family - the page collects all Servo & drive-family codes we have handled, with the common inspection order and spares.
Other brands: see our KUKA, ABB, Yaskawa and Universal Robots field-fix libraries — or the full 10-brand hub.

Frequently asked questions

QWhat does the FANUC srvo-046 alarm mean?

The average current over a period exceeded the rating - the axis has been working too hard for too long. This is a high-frequency ticket for our FANUC repair team, and on R-30iA / R-30iB / R-30iB Plus systems one inspection usually identifies the fault. FANUC srvo-046 sits in the servo & drive family; on our work orders the highest-frequency trigger for this code is "Payload/inertia settings lower than the real tooling".

QCan I clear a FANUC srvo-046 alarm myself?

Whether FANUC srvo-046 clears on its own depends on the outcome of "Correct payload and inertia settings first - free and often the fix". Finish the flow with "Check brake release with servo on: axis should move freely when pushed (in a safe test)" to confirm FANUC srvo-046 - do not skip it. If that step is clean, the second most frequent cause on FANUC srvo-046 is "Mechanical binding or degraded reducer increasing friction". Two attempts and still there means stop: FANUC srvo-046 involves live servo circuits and rotating parts, and running FANUC srvo-046 on can turn a repairable fault into a replacement.

QFor servo alarms like FANUC srvo-046, how do you tell motor from drive?

The commonest causes we see on FANUC srvo-046 are "Payload/inertia settings lower than the real tooling, Mechanical binding or degraded reducer increasing friction, Duty cycle too aggressive (speed/accel too high for the load)", so we stock the van against those. For FANUC srvo-046 specifically, we bring the scope and meter; motors and drives are stocked by type, and most cases are measured before parts are ordered. For FANUC srvo-046, on servo alarms we specifically avoid misjudgement: waveform first, parts second, so customers skip needless swaps. Before we roll, tell us what FANUC srvo-046 shows on the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code and what the machine was doing - phone or video triage is free.

This page on FANUC srvo-046 was compiled from actual repair records of the Henghuan Robotics repair team. Alarm notes are our own summary for troubleshooting reference only and may vary with controller and software version — please consult FANUC documentation or contact us if in doubt. Henghuan is an independent service provider, not affiliated with or endorsed by FANUC.