SRVO-014

Identify the failed fan location

Check the alarm detail screen on the teach pendant: Press MENU → ALARM → F1 [TYPE] → select 'Servo'. The alarm detail will show 'FAN#X ABNORMAL' where X indicates the fan number (typically FAN1, FAN2, or FAN3 on the controller backplane). Note this number before the controller stops.

You have approximately 60 seconds before automatic shutdown. Note the fan number immediately.

Physically verify fan operation

Open the controller cabinet door and visually inspect the indicated fan on the backplane. Listen for abnormal bearing noise (grinding or squealing). Use a finger to gently check for fan blade resistance (ensure power is on but DO NOT obstruct airflow). A seized fan will not rotate or will rotate very slowly.

Keep hands clear of rotating fan blades. Do not insert tools or objects into the fan guard.

Attempt fan motor restart

If the fan blade is stuck but motor is energized, power down the controller completely (not just E-stop). Manually rotate the fan blade several times to check for bearing seizure. Power up the controller and observe if the fan starts normally. If bearing noise is present or fan fails to reach speed, replacement is required.

On R-30iB controllers, fans are hot-swappable on some backplane models. Check your specific backplane part number before attempting removal with power on.

Replace the defective fan motor

Order the correct replacement fan (typically Fanuc part A05B-2490-C3xx series depending on controller model). Power down the controller, remove the four mounting screws on the fan assembly, disconnect the 3-pin or 4-pin fan connector from the backplane, and replace with new fan. Verify connector polarity matches before reconnection.

Keep a spare fan in your parts inventory. Fans typically last 30,000-50,000 hours but failure can be sudden. Common replacement interval is 5-7 years in clean environments.

Inspect cabinet air filter condition

Remove the air filter panel (typically located on the controller cabinet door or bottom front panel). Examine the filter media for dust accumulation, discoloration, or blockage. Hold the filter up to a light source—if less than 50% light passes through, the filter requires cleaning or replacement.

R-30iA/B controllers typically use washable foam filters or disposable pleated filters. Check filter part number on the filter frame—common types are A05B-2490-H951 (foam) or H952 (pleated).

Clean or replace the air filter

For foam filters: wash with mild detergent and warm water, rinse thoroughly, squeeze (do not wring), and air dry completely before reinstalling. For pleated filters: use compressed air (30 PSI max) to blow from clean side to dirty side, or replace if heavily contaminated. Reinstall securely.

Never operate the controller without the air filter installed. Even brief operation without filtration can contaminate servo amplifiers and backplane electronics.

Check internal airflow obstructions

With the controller powered down, inspect inside the cabinet for debris, loose wires blocking airflow paths, or dust accumulation on heat sinks. Verify the exhaust vents on the cabinet top or sides are not blocked by objects or mounted too close to walls. Minimum clearance is typically 200mm (8 inches).

Use a vacuum with a HEPA filter or compressed air to clean the backplane area every 6-12 months in dusty environments. Pay special attention to servo amplifier heat sinks.

Establish preventive filter maintenance

Check filter condition monthly in normal environments, weekly in dusty environments. Log filter service dates in the robot maintenance records. Consider upgrading to higher-efficiency filters or adding a pre-filter if dust accumulation is excessive.

If SRVO-014 recurs within weeks after filter cleaning, the environment may require external air filtration or cabinet pressurization systems.

Inspect fan motor connector and wiring

Power down the controller and locate the fan connector on the backplane (3-pin or 4-pin Molex-style connector). Check for loose connection, bent pins, or signs of arcing/burning. Disconnect and inspect the pins—corrosion or discoloration indicates poor contact. Check wire integrity from connector to fan motor housing.

Never disconnect or reconnect fan connectors with controller power on. This can damage the fan control circuit on the backplane.

Measure fan power supply voltage

With controller powered on and using a multimeter, carefully measure DC voltage at the fan connector (typically pin 1 = +DC, pin 2 = GND, pin 3 = tachometer signal). Expected voltage is 24VDC ±10% or 48VDC ±10% depending on fan model. If voltage is below specification, there is a backplane power supply fault.

The tachometer signal (pin 3) should show a pulsing DC voltage (typically 0-5VDC) when the fan is rotating. No signal indicates fan motor failure or tachometer circuit fault.