Normally Closed

**Normally Closed**

The term “Normally Closed” (NC) refers to a type of electrical switch or relay contact that remains closed in its default state, allowing current to flow until it is actuated or triggered to open. In this state, the circuit is complete, and power passes through uninterrupted. When activated, the contact opens, breaking the circuit and stopping current flow. This concept is commonly used in control systems, safety devices, and automation to ensure that machinery or processes default to a safe or active condition when power is lost or the system is at rest. Understanding “Normally Closed” contacts is essential for designing and troubleshooting electrical and electronic circuits.