Which precaution should be taken before opening any part of a refrigeration system for non-major repairs?

Bringing the part of the refrigeration system to 0 psig is essential before opening it for non-major repairs because it ensures that the system is at a safe pressure level, minimizing the risk of refrigerant release. At 0 psig, the pressure is equal to atmospheric pressure, which helps prevent the sudden escape of refrigerant and potential injury to personnel or damage to equipment. This is a crucial safety measure in the maintenance of refrigeration systems.

Maintaining the system at atmospheric pressure also aids in ensuring that no harmful refrigerant gas is present in high concentrations which could pose health risks or environmental hazards. By equalizing the pressure, technicians can safely conduct repairs without worrying about the dangers associated with handling pressurized systems or hazardous materials.