ABB ACS550-01 / ACS550-U1 Error 18: THERM FAIL

ACS550-01/U1 drive · taken from the manufacturer’s manual, pages cited

Fault code18

THERM FAIL occurs due to internal thermistor measuring drive temperature being open or shorted. The manual's first action is: “Contact your local ABB representative.”

Model
ABB ACS550-01 / ACS550-U1
Display shows
THERM FAIL (18)
Type
Fault code
Source
Manual p. 245

What 18 means

THERM FAIL p. 262

Common causes

  • Internal fault. The thermistor measuring the internal temperature of the drive is open or shorted. p. 262

What to do

  1. Contact your local ABB representative. p. 262

Before you service the product, read the safety instructions in the manual p. 6.

If 18 is still not resolved

  • contact your local ABB representative for replacement p. 6
    “Never attempt to repair a malfunctioning drive; contact your local ABB representative for replacement.”
  • For more technical information, contact your local ABB representative. p. 7
    “For more technical information, contact your local ABB representative.”
Open the manual at page 245 All ACS550-01 / ACS550-U1 error codes Manual details & download

This page summarises what the manufacturer’s manual says about 18; 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 ABB. Found a mistake? Report an error.