Which procedure is crucial before performing maintenance on a refrigeration system?

Before performing maintenance on a refrigeration system, ensuring the unit is powered is crucial as it allows the technician to fully understand the system's current operational state. By verifying that the power is connected, the technician can observe any electrical issues, listen for operational sounds, and check for the correct indicators of system performance. This step is essential because it sets the foundation for safe and effective maintenance.

Once power is confirmed, the technician can safely perform checks and repairs, ensuring that they will not inadvertently cause further damage or create hazardous conditions. It also allows for tests that may require the system to be operational, enabling troubleshooting of issues that may only be apparent when the system is running. Overall, confirming that the unit is powered up is an essential first step in the maintenance process.