Prior to making a continuity check, what must be done to an electrical circuit?

Before performing a continuity check on an electrical circuit, it is crucial to turn the power off. This step ensures safety for both the technician and the equipment. When power is applied to a circuit, there may be voltage present, which can lead to electric shock or damage to sensitive testing equipment. Additionally, having power on could result in misleading readings, as other components in the circuit may still be active, affecting continuity measurements.

Turning off the power eliminates these risks and allows for an accurate assessment of the circuit's integrity without interference from active electrical components. This is a standard safety practice in electrical maintenance and troubleshooting.