UL 508 A: Industrial Control Panels

UL 508A - Definitions

What are Branch circuits, Feeder circuits, Power circuits and Control circuits?

Branch circuit:it is the utility circuit; it is the part of the circuit that starts from the load (e.g. motor) and ends at the first short circuit protection (Branch Circuit Protection Device or BCPD).

Feeder circuit: indicates the supply circuit, i.e. all the elements upstream of the BCPD.

Power circuit: the power circuit (e.g. motor starter); it can be connected directly to the supply circuit or supplied by a power transformer.

Control circuit: it is the circuit that transmits the control signals for the machines or the system. Control circuits are generally limited to 15 A.

Power circuits and Control circuits require the appropriate protection devices (UL 508, UL 489 or UL 1077).

An example of Branch Circuit and Feeder Circuit taken from the Standard is shown in the figure here next.

Safety in Collaborative Robotics

There is no “Collaborative Robot”. That is one of the first statements you hear from people working in Collaborative Robotics. The reason is because the robot can be designed for a collaborative task, but it is the Application that makes the “Robot Collaborative”. The reference standard for Collabo