What is a holding contact in a control circuit and why is it used?

• A. A holding contact is a fuse that protects the circuit.
• B. A holding contact is a normally open or closed contact that maintains a circuit’s state after the initiating device is released, providing a latch or self-hold.
• C. A holding contact is a timer that delays release.
• D. A holding contact is a lamp indicator.

Answer: (B)

Holding contact is an auxiliary contact, usually the relay’s own contact, that keeps the circuit energized after the initiating device is released, creating a latch or self-hold. In a typical start-stop control, pressing a momentary start pushbutton energizes the relay coil. The relay’s normally open holding contact closes and provides a path around the start button, so when you release the start button, current still flows to the coil and the relay stays energized. A stop pushbutton (normally closed) in series will interrupt this path to de-energize when pressed. This arrangement lets the circuit stay on without you having to hold the button down and provides reliable, continuous operation.

Other options don’t fit because a fuse provides protection, not holding the circuit; a timer delays release rather than maintaining the state; and a lamp indicator shows status but does not keep the circuit energized.