What should the operator always do before changing the blade on a portable saw?

• A. Unplug
• B. Lock the switch
• C. Turn off the power at the breaker
• D. Unplug the cord and wait for the blade to stop

Answer: (A)

The main idea is to ensure there is no electrical power reaching the tool before you touch the blade. Unplugging the saw removes the power source completely, so there’s no risk of the motor starting if the switch is bumped or a cord is pulled. This provides the strongest, simplest guarantee that the blade can’t move while you’re changing it.

Turning off the switch might seem safe, but if the switch is faulty or someone could re-energize the tool, power could still be present. Turning off the breaker cuts power to the circuit but is less practical for routine blade changes and can affect other devices on the same circuit. Waiting for the blade to stop addresses motion during operation, not the guarantee that the tool is de-energized for maintenance. For cordless models, removing the battery achieves the same zero-energy objective. So, unplugging (or removing the battery) is the best practice to safely change the blade.