What is the function of a control transformer in control circuits?

Prepare for the NCCER Electrical Level 2 Control Systems and Fundamental Concepts exam. Utilize flashcards and multiple choice questions with hints and explanations. Ensure success on your exam!

Multiple Choice

What is the function of a control transformer in control circuits?

A control transformer steps down incoming line voltage to a lower, safe control voltage and provides isolation between the power and control circuits. This lower voltage powers control devices like relays, contactors, timers, and PLC input modules, while the isolation helps protect personnel and equipment from faults on the power side and reduces electrical noise in the control circuit. It doesn’t raise voltage for motors, nor does it convert AC to DC (that’s a rectifier), and while PLCs use low voltage, their memory is typically supplied by a dedicated DC power supply rather than directly by the transformer.

A control transformer steps down incoming line voltage to a lower, safe control voltage and provides isolation between the power and control circuits. This lower voltage powers control devices like relays, contactors, timers, and PLC input modules, while the isolation helps protect personnel and equipment from faults on the power side and reduces electrical noise in the control circuit. It doesn’t raise voltage for motors, nor does it convert AC to DC (that’s a rectifier), and while PLCs use low voltage, their memory is typically supplied by a dedicated DC power supply rather than directly by the transformer.

More practice questions