Which sequence correctly describes the startup steps for a centrifugal chiller?

• A. Start the chilled water pump, start condenser water pump, check oil, start cooling tower, start compressor
• B. Start the compressor, start chilled water pump, start condenser water pump, check oil, start cooling tower
• C. Check oil, Start chilled water pump, Start condenser water pump, Start cooling tower, Start compressor
• D. Start chilled water pump, Start cooling tower, Start condenser water pump, Check oil, Start compressor

Answer: (A)

Starting a centrifugal chiller safely hinges on having the water circuits flowing and the lubrication ready before the compressor comes on. Begin by starting the chilled-water pump so the evaporator has circulating water to absorb heat. Then start the condenser-water pump to ensure there’s a flow path for rejecting heat. Next, check the oil to confirm the lubrication system is ready and the compressor can be properly lubricated when it runs. After confirming lubrication, bring the cooling tower online to provide condenser cooling and help establish stable condenser pressures. Only then start the compressor, since you want heat rejection and proper lubrication already in place before the compressor operates. Starting the compressor without established water flow or adequate oil, or without cooling on the condenser, can lead to equipment damage or unsafe operating conditions.