What is the Main function of UA or BA control units for Automatic transfer switch ATS using MCCB ?

The UA or BA controllers are used to control the operation truth table for an automatic transfer switch system (1 out 2),

they provide all the scenarios of breakers "which CB will operate and which will be opened during different operational conditions"

This is to keep the trasfering function fully automated between the two CBs

Released for:Schneider Electric South Africa