What the SRVO-045 alarm means

Abnormally high instantaneous current flowed from the amplifier to the motor, usually indicating a short circuit. We fix this FANUC R-30iA / R-30iB / R-30iB Plus fault almost daily, and one round of on-site checks usually confirms what is going on.

Most common causes

  • Motor power cable shorted (insulation worn at robot wrist/base is common)
  • Motor winding shorted to ground
  • Servo amplifier power module (IPM) failed
Field note: We have tallied real cases: the first cause tops the list, so start your diagnosis there.

Step-by-step field fix

  1. Megger-test the motor power cable and motor winding for ground shorts
  2. Inspect the cable at flex points (wrist, J3, base) for worn insulation
  3. Disconnect the motor cable at the amp - if the alarm persists, the amplifier is faulty
  4. Replace the shorted component; do not just reset and retry repeatedly
Safety first: For FANUC srvo-045, servo circuits are live and motor shafts and reducers rotate: measuring current waveforms or winding resistance means contact with live or moving parts. The self-serviceable action is Megger-test the motor power cable and motor winding for ground shorts; anything past that falls under live servo circuits and rotating parts and needs a certified engineer.

How we diagnose servo alarms on site

FANUC srvo-045 belongs to the servo & drive family. On FANUC srvo-045 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-045 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-045 runs: target -> position loop -> velocity loop -> current loop -> power output -> motor -> feedback -> loop compare.

The classic misjudgement on FANUC srvo-045 is here: The easiest misjudgement in this family is blaming the drive for mechanical drag. The discriminator is the current waveform: normal at no load but clearly raised and wavering under load points at mechanics (reducer, bearings, assembly stress); abnormal already at no load, or spiky and oscillating, points at electrics (drive, motor windings, feedback). We capture the waveform on site before concluding anything, and decide parts after measurement - which saves customers paying for swaps they did not need.

Field notes on this page cover FANUC srvo-045 (HCAL Alarm - High Current); written by the Henghuan repair team, updated 2026-10-01.

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Tell us these three: alarm code, robot model, and the operating condition at the alarm. FANUC srvo-045 FANUC srvo-045 is a diagnosis our engineers do daily, and phone/video remote diagnosis is free.

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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-046 — OVC Alarm - Overcurrent (Average)
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-045 alarm mean?

Abnormally high instantaneous current flowed from the amplifier to the motor, usually indicating a short circuit. We fix this FANUC R-30iA / R-30iB / R-30iB Plus fault almost daily, and one round of on-site checks usually confirms what is going on. FANUC srvo-045 sits in the servo & drive family; on our work orders the highest-frequency trigger for this code is "Motor power cable shorted (insulation worn at robot wrist/base is common)".

QCan I clear a FANUC srvo-045 alarm myself?

Whether FANUC srvo-045 clears on its own depends on the outcome of "Megger-test the motor power cable and motor winding for ground shorts". Finish the flow with "Replace the shorted component; do not just reset and retry repeatedly" to confirm FANUC srvo-045 - do not skip it. If that step is clean, the second most frequent cause on FANUC srvo-045 is "Motor winding shorted to ground". Two attempts and still there means stop: FANUC srvo-045 involves live servo circuits and rotating parts, and running FANUC srvo-045 on can turn a repairable fault into a replacement.

QFor servo alarms like FANUC srvo-045, how do you tell motor from drive?

The commonest causes we see on FANUC srvo-045 are "Motor power cable shorted (insulation worn at robot wrist/base is common), Motor winding shorted to ground, Servo amplifier power module (IPM) failed", so we stock the van against those. For FANUC srvo-045 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-045, on servo alarms we specifically avoid misjudgement: waveform first, parts second, so customers skip needless swaps. Before we roll, tell us what FANUC srvo-045 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-045 was written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your FANUC documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by FANUC.