Which of the following is a function of a safety interlock switch?

A safety interlock switch is designed to enhance operator safety by ensuring that certain conditions are met before a machine can operate. Specifically, one of its primary functions is to prevent machine operation if safety guards or protective barriers are not properly in place. This is crucial because it minimizes the risk of injury by ensuring that hazardous moving parts are enclosed and inaccessible to operators while the machine is running.

Additionally, if a guard is removed or improperly positioned, the interlock switch will stop the machine, preventing any accidental startup that could lead to serious injuries. Furthermore, some interlock systems are designed to ensure that operators cannot manipulate machinery parts while the machine is powered. This is particularly important to avoid accidents during maintenance or adjustment phases.

Each of these functions contributes to a safer working environment by reducing the likelihood of operator errors and accidents associated with machine operation. Since all these options represent valid scenarios where a safety interlock switch plays a critical role in ensuring safety during machine operation, the correct choice encompasses all of them.