Which device is given as an example of an interlock safety mechanism that stops startup until a condition is met?

Which device is given as an example of an interlock safety mechanism that stops startup until a condition is met?

• A. A pressure switch that prevents startup until pressure is high enough
• B. A light indicator that shows status
• C. A timer that delays startup by a fixed interval
• D. A push button that starts the machine regardless of conditions

Answer: (A)

Interlocks block action until a condition is satisfied. A pressure switch used as an interlock monitors the system pressure and sits in the control path so the machine cannot start until the pressure is within a safe range. This directly enforces a required condition before operation, which is the essence of an interlock: safety is ensured by preventing startup if conditions aren’t met. In this context, a light indicator only shows status and doesn’t stop startup. A timer delays startup but doesn’t verify a safe condition, so startup could proceed even if conditions are unsafe. A push button starts the machine regardless of conditions, bypassing any safety check. That makes the pressure switch the correct example, because it actually prevents the start until the specified condition is met.

Interlocks block action until a condition is satisfied. A pressure switch used as an interlock monitors the system pressure and sits in the control path so the machine cannot start until the pressure is within a safe range. This directly enforces a required condition before operation, which is the essence of an interlock: safety is ensured by preventing startup if conditions aren’t met.

In this context, a light indicator only shows status and doesn’t stop startup. A timer delays startup but doesn’t verify a safe condition, so startup could proceed even if conditions are unsafe. A push button starts the machine regardless of conditions, bypassing any safety check. That makes the pressure switch the correct example, because it actually prevents the start until the specified condition is met.