The type SCA11A relay consists of two telephone type relay units with their associated static timing and regulating circuits all mounted in a size S-1 drawout case. The type SCA11A relay is designed to provide the automatic check back of a carrier current channel from a remote unattended station.

The type SCA51A relay is a carrier auxiliary relay for use in conjunction with power line carrier or microwave channels and static protective relaying equipment in directional comparison relaying schemes. The relay includes five separate relay functions which can be used singly or in combination. The desired mode of operation is selected by means of internal links and by making the appropriate external connections. The relay also includes a target.

The type SCA52A relay is similar in functionality to the SCA51A but with six relay functions.

End of life notice: The SCA has been discontinued as of October 1, 2013.
Read full notice.