Maintenance, Service and Decommissioning
Core concepts
Planned maintenance prevents failure and satisfies compliance. Know scheduled tasks: coil cleaning, filter changes, belt and bearing checks, electrical torque and insulation checks, refrigerant leak detection, control calibration, and safety switch proving. Understand condition monitoring through superheat, subcooling, approach temperatures, amp draw and oil condition. Service work must protect the environment: recover refrigerant before opening the circuit, never mix refrigerants, label cylinders, and record quantities. Decommissioning is a controlled process: isolate and lock out, recover all charge, purge lines, remove oil and components lawfully, cap and seal openings, and document the final state. Traps include treating a maintenance visit as a quick visual check, skipping leak detection on larger charges, and disposing of refrigerant-containing equipment without recovery.
Traps
Questions may ask what to do first at decommissioning; recovery and isolation precede dismantling. Also distinguish reclaim (to specification) from recycle (basic clean-up).
Worked example
Decommissioning a split system: isolate power and lock out, record the refrigerant type and charge, recover into a dedicated cylinder until the system reaches vacuum, weigh the recovered amount, purge with dry nitrogen, disconnect and cap pipework, then document and arrange lawful disposal of the equipment and oil.
Rule of thumb
Maintenance is measurement plus records; decommissioning is recovery plus records.