Final answer:
The first task when performing pre-start service of an absorption refrigeration system is to lock out all sources of energy. This safety step ensures that the maintenance can be performed without risk of accidental equipment activation, which is critical before any checks or maintenance procedures are carried out.
Step-by-step explanation:
When performing pre-start service of an absorption refrigeration system, the first task is to lock out all sources of energy. This safety measure prevents any accidental startup of equipment during maintenance, which can lead to injury or damage. Pre-start services involve numerous checks and procedures that are critical for proper functioning and safety of the refrigeration system. It is essential to ensure that energy sources including electricity and any fuel supplies are securely shut off and cannot be inadvertently re-activated. After locking out the energy sources, technicians can proceed with tasks such as cleaning cooling and chilled water strainers, checking lubricants in circulating pumps and fans, and opening the valves in the cooling and chilled water systems. The overarching purpose of these systems, whether they are household refrigerators or larger commercial air conditioning units, is to transfer heat from a cold environment to a warmer one, which is essential for controlling the temperature of the space being cooled.