ABB ACS580 VFD
ABB ACS580 VFD code B5A0: STO event
The safe torque off function is active because a safety signal is lost, causing the drive to stop.
Safety first. This code involves a gas, flame or electrical hazard. Do not keep resetting it. Leave burner, gas train and high voltage work to a qualified technician. WERCS answers 24/7 at (877) 489-3727.
- Code
- B5A0
- Name
- STO event
- Controller
- ABB ACS580 VFD
- Type
- Safety interlock
- What it does
- Warning: the equipment keeps running and flags a problem
- Risk
- RED Specialist territory
- Reset
- Clears on its own when the condition goes away
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
Subscribers get:
- What to do next, in plain words
- What the manual says to do, and the page it is on
- The 1 common cause listed for this code
- The step by step check for this problem, one check at a time
- Booking a live video call with Ben, a master booth technician ($250/hr, paid per call)
Questions about this code
What does ABB ACS580 VFD code B5A0 mean?
The safe torque off function is active because a safety signal is lost, causing the drive to stop.
Is ABB ACS580 VFD code B5A0 dangerous?
It is graded red, specialist territory: it involves a burner, gas, flame or safety lockout, so leave the repair to a qualified technician.
How do I fix ABB ACS580 VFD code B5A0?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.