DOC-0017-03-EN: AC15 Series - Hardware Installation Manual 
  DOC-0017-03-EN-B   04.04.2023   49 (125) 
 EMC 
In addition to the mandatory requirements of EN61800-3, the STO functionality has been subjected to 
testing for immunity at higher levels. In particular, the STO function (only) has been tested for radiated 
immunity according to EN61800-5-2:2017 Annex E up to 6GHz which includes frequencies used by mobile 
transmitters in general. 
 
8.4  STO Operation 
 Terminal Identifications 
 
 
 
 
 
 
Frame 1 
13  STOA 
-  0V or not connected, STO is ‘Active’ on channel A. Drive 
will not run. 
-  24V, STO is ‘Disabled’ on channel A. Drive will run, 
providing 24V is present on STO input channel B too. 
-  Input is optically isolated from all other inverter terminals 
14  0V 
-  Signal return for STO input channel A and STO input 
channel B.  
-  This terminal must be connected to earth at one common 
point in the drive system. 
15  STOB 
-  0V or not connected, STO is ‘Active’ on channel B. Drive 
will not run. 
-  24V, STO is ‘Disabled’ on channel B. Drive will run, 
providing 24V is present on STO input channel A too. 
-  Input is optically isolated from all other inverter terminals