Fanuc Alarm SV0438 AL-b AL-c AL-d Alarm Information by KFASLLC

KFAS: Fanuc CNC Parts, Service, & Repair

Fanuc ALARM SV0438 aiSV-B AL-b, AL-c, AL-d

Alarm SV0438 Fanuc 0iF or 31iB and AL-b, AL-c, AL-d on aiSV-B means,
an abnormal motor current has been detected.
Cause and troubleshooting
(a) Check whether the following parameters have the default values described in PARAMETER MANUAL (B-65270EN).
No.2004
No.2040
No.2041

Alternatively, if an abnormal motor current alarm condition occurs only on rapid acceleration/deceleration, increase the acceleration/deceleration time constant, and see.

(b) Remove the motor power leads from the servo amplifier and cancel the emergency stop.
<1> If no abnormal motor current occurs
→ Go to (d).
<2> If an abnormal motor current occurs
→ Replace the servo amplifier.
(c) Remove the motor power leads from the servo amplifier and check the isolation between the U,
V, or W motor power lead and the PE.

<1> If the insulation is deteriorated
→ Go to (e).
<2> If the insulation is normal
→ Replace the servo amplifier.
(d) Disconnect the motor from its power leads, and check whether the insulation of the motor or
power leads is deteriorated.
<1> If the insulation of the motor is deteriorated
→ Replace the motor.
<2> If the insulation of any power lead is deteriorated
→ Replace the power lead.
(b) Remove the motor power leads from the servo amplifier and cancel the emergency stop.

A06B6240 aiSV-B B65515EN Maintenance Manual

*CAUTION: High Voltage present.
Note: Some Machine's electrical cabinet doors are equipped with "door interlock" that will cause the breaker to trip when the door is open.
See the machine's manual for information on how to bypass so that you can observe the alarm LED status

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