Mitsubishi Electric AL.8A

Brand: Mitsubishi ElectricModel: PLC (FX5U / iQ-R / iQ-F Series)Error code: AL.8A

What the Fault Means

STO input signal error

Likely causes

  • STO input activated unexpectedly; wiring fault

Solution and Safe First Checks

  1. Check STO wiring at CN8; verify safety relay circuit

Safety: do not work inside the panel without isolating the power; if unsure, consult a qualified technician.

Related Mitsubishi Electric error codes

Source: the Zeror.ai industrial fault database and Mitsubishi Electric technical documentation. This page is for information; on critical systems follow the manufacturer's manual and authorised service.

Mitsubishi Electric AL.8A · Zeror.ai