Siemens MICROMASTER 420 Error A0503: Undervoltage Limit

Siemens MICROMASTER 420 inverter · taken from the manufacturer’s manual, pages cited

Warning codeA0503

The inverter has detected a voltage level below the minimum acceptable limit. The manual's first action is: “Check main supply voltage (P0210)”

Model
Siemens MICROMASTER 420
Display shows
Undervoltage Limit (A0503)
Type
Warning code
Source
Manual p. 72

What A0503 means

Undervoltage Limit p. 72

Common causes

  • Mains supply too low p. 72
  • Short mains interruption p. 72

Safety warnings — read before you start

  • DANGERDANGER. indicates an immiently hazardous situation which, if not avoided, will result in death or serious injury. p. 6
  • WARNINGWARNING. indicates a potentially hazardous situation which, if not avoided, could result indeath or serious injury. p. 6
  • CAUTIONCAUTION. used with the safety alert symbol indicates a potentially hazardous situationwhich, i f not avoided, may result in minor or moderate injury. p. 6

What to do

  1. Check main supply voltage (P0210) p. 72

If A0503 is still not resolved

  • Contact your service dealer for assistance. p. 72
    “Check main supply voltage (P0210)”
Open the manual at page 72 All MICROMASTER 420 error codes Manual details & download

This page summarises what the manufacturer’s manual says about A0503; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with Siemens. Found a mistake? Report an error.