Forums » Electrical Engineering


    • 6 posts
    September 14, 2019 4:01 AM PDT

    What is AT and AF of 60AT/100AF MCCB CIRCUIT BREAKER?

    • 157 posts
    September 14, 2019 5:53 AM PDT

    I believe it refers to trip size and frame size (T & F)


    AT - denotes for tripping rate for breaker

    AF- denotes frame size 

    • 103 posts
    September 14, 2019 7:44 PM PDT

    Agree with Dennis that the breaker trip unit is 60A & the Frame size is 100A or the highest trip rating that breaker family has is 100A.

    A stands for Ampere

    T for Trip

    F for Frame