NVIC 17-14 Task 4.3.T

Operate main and auxiliary machinery and associated control systems

OICEW-A4.3 Preparation, operation, fault detection and necessary measures to prevent damage for the following machinery items and control systems

Other auxiliaries including refrigeration, air- conditioning and ventilation systems

On a vessel of at least 1,000 HP, on a simulator, or in a laboratory,

the candidate starts an air-conditioning or refrigeration system.

The candidate:

1. Checks the crankcase oil level - the level should be visible in the sight glass;

2. Lines up the condensing water circulating system by opening the condensing water isolation valves and venting the waterboxes to ensure condenser watersides are full;

3. For chillers, lines up the chilled water system by opening the chilled water isolation valves and venting the waterboxes to ensure chiller watersides are filled;

4. Opens the compressor discharge and main liquid line (king) valves;

5. Opens the compressor suction valve approximately one full turn;

6. Depresses the start button and starts the compressor in the auto mode;

7. When compressor starts, slowly opens the compressor suction valve to help prevent excessive oil foaming (due to rapid crankcase pump-down) until the suction valve is fully open; and

8. By monitoring the suction temperature and listening for any evidence of compressor knocking (due to liquid floodback), throttles down on the suction valve until liquid in the suction line has successfully flashed off, then slowly opens the suction valve until fully open.