FANUC Alarm SRVO-044 — SERVO HVAL alarm

Description

The DC voltage (DC link voltage) of the main circuit power supply is abnormally high. The LED indicator of the servo amplifier PSM displays '7'.

Remedy

1. Check the three-phase input voltage applied to the servo amplifier. When the voltage is 253 VAC or higher, check the input power supply voltage. If the motor is abruptly accelerated or decelerated while the three-phase input voltage exceeds 253 VAC, this alarm might be issued. 2. Check whether the applied load is within the rated value. If the rated load is exceeded, reduce the applied load. If a load exceeds the rated value, built-up regenerative energy might this alarm to be issued even when the three-phase input voltage satisfies the specifications. 3. Check the cables (CN3 and CN4) in the amplifier. Replace them if necessary. 4. Check the cable between the main CPU printed circuit board (JRV1) and the printed circuit board for the emergency stop control (JRV1). 5. Replace the servo amplifier.

Field diagnosis

The DC voltage of the intermediate bus is too high: mains voltage too high, transformer wired incorrectly or regeneration not absorbed.

What to check

• Measure the cabinet input voltage and check the transformer tap; check the three-phase supply at the amplifier input (above 240 V, look on the supply network side).
• If the supply is correct, discharge circuit, then amplifier.
• Note: A change of the workshop supply transformer brings this code up on an entire line at once.

Related codes

Same hardware involved