The most important administrative control related to electrical safety is lockout/tagout (LOTO). OSHA requires LOTO procedures to protect workers whenever maintenance or repair tasks are being performed on electrical equipment. These measures are necessary to reduce the risk of shock or injury due to the unexpected startup of equipment or the release of hazardous energy while a machine or instrument is out of service.
If you see a lock on an electrical circuit, do not attempt to operate the circuit.