Home › Chiller procedures

Startup · Shutdown · Pump-down · Recovery

Chiller procedures, step by step

Every step of the trainer's procedures for the steam-turbine centrifugal and the reciprocating chiller, with the reason behind each one. Read them here, then run them in 3D.

CH-1 steam-turbine chiller startup (from lay-up)CH-1 normal shutdown and winter lay-upCH-1 refrigerant recovery with the RSR unitCH-3 reciprocating chiller startup (from lay-up)CH-3 pump-down and lay-up

These are the training procedures used in the simulator, written for exam study. Real equipment has its own manufacturer procedures; always follow those and your site's procedures on the job.

CH-1 steam-turbine chiller startup (from lay-up) Centrifugal (CH-1) · 43 steps

  1. Check the refrigerant detectorIt should read near zero with no alarm. Never start into an active refrigerant alarm.
  2. Check the oil temperatureThe oil heater must have been on so the oil is warm and free of refrigerant.
  3. Check the oil levelOil should be visible between the marks in the sight glass.
  4. Check the evaporator refrigerant levelLiquid visible in the evaporator sight glass.
  5. Open the compressor suction valveIt was closed for service. Never run the compressor with it shut.
  6. Open the compressor discharge valveRunning against a closed discharge valve drives pressure straight to the high-pressure cutout.
  7. Open the liquid line valveLiquid can now feed from the condenser through the metering device to the evaporator.
  8. Close the tower basin drain valveThe basin was drained for the winter. Close the drain before filling.
  9. Open the tower make-up (fill) valve and fill the basinThe float valve fills the basin and then shuts off. Wait for the level to come up.
  10. Inspect the fan belt and driveBelt tight and in good condition, sheaves aligned, fan free to turn, nothing loose on the fan deck. No lock on the disconnect.
  11. Open the condenser-water inlet valveBoth condenser valves must be open for flow.
  12. Open the condenser-water outlet valve
  13. Open the chilled-water inlet valveBoth evaporator valves must be open for flow.
  14. Open the chilled-water outlet valve
  15. Start the chilled-water pumpStart it and let the flow settle.
  16. Verify chilled-water flowPressure drop across the evaporator near design (about 9.5 psi here) and the flow switch closed.
  17. Start the condenser-water pumpIt draws from the tower basin you just filled.
  18. Verify condenser-water flowPressure drop across the condenser near design (about 11 psi here).
  19. Enable the cooling tower fanThe fan control will run it as needed to hold the tower setpoint.
  20. Close the knife switchControl power on at the disconnect switch box (no lock on the hoop).
  21. Check control airAbout 90 psig at the control air gauge: the governor, recirculating and overboard valves all need air.
  22. Open condensate 1/4-turn valve 1Main vertical steam line drain into the main condensate tank. All three condensate valves are opened for the warm-up.
  23. Open condensate 1/4-turn valve 2Drip leg and steam trap line into the condensate tank.
  24. Open condensate 1/4-turn valve 3Governor valve condensate line into the condensate tank.
  25. Open the drip leg steam-side 1/4-turn valveSo the drip leg drains through the strainer and the steam trap.
  26. Open the drip leg condensate-side 1/4-turn valve
  27. Fill the hotwell: open the hotwell make-up valveBring the hotwell level up to about half in its sight glass. Watch the level rise in the glass.
  28. Close the hotwell make-up valveThe level controller holds the hotwell from here on.
  29. Put condensate pump 1 in AUTOHOA switch to AUTO: the hotwell level controls start it.
  30. Put condensate pump 2 in AUTOPump 2 is the lag pump.
  31. Open the gland seal steam by-pass 1/4-turn valveSeal steam to both glands, about 5 psig on the gland seal gauge, so no air leaks in along the shaft.
  32. Start the vacuum pumpsCity water make-up open for their seals. Pull the surface condenser down to about 26 in. Hg vacuum.
  33. Open the turbine casing drain valves (seal end)Drain condensate from the cold casing during warm-up.
  34. Open the turbine casing drain valves (thrust end)
  35. Crack open the turbine bypass valve and warm the turbineA small amount of steam warms the casing slowly: about 15–20 minutes on a real machine (about 25 s here). Watch the Steam page warm-up reading.
  36. Close the turbine bypass valveNever run with it open: it bypasses the governor and the turbine can overspeed.
  37. Close the turbine casing drain valvesBoth ends.
  38. Check the overspeed trip is setThe trip handle latched and the trip valve open; vacuum breaker closed.
  39. Check the turbine oil levelOil visible in the turbine oil reservoir sight glass.
  40. Open the manual steam (Gimbal) valve fully counter-clockwiseSteam is now at the trip valve and the governor valve; the governor stays closed until the panel starts the turbine.
  41. Check setpoints and alarms on the control panelLeaving chilled-water setpoint, demand limit, no active alarms. Press the Steam button: warm-up complete, vacuum above 20 in. Hg.
  42. Press ON (START) on the control panelThe panel proves both flows and the condenser vacuum, runs the compressor oil pump and the turbine auxiliary oil pump pre-lube, then opens the governor valve and brings the turbine up to speed.
  43. Check the running readings and log themTurbine speed about 4,450 rpm (Steam button, or the laser tachometer at the shaft coupling), exhaust vacuum about 26 in. Hg, bearings about 160 / 170 °F, gland seal about 5 psig, suction and head pressures, oil pressure. Record them in the log.

Practice this procedure in 3D

CH-1 normal shutdown and winter lay-up Centrifugal (CH-1) · 17 steps

  1. Press OFF (STOP) on the control panelThe governor valve closes and the turbine coasts down. Always stop with OFF, never with the knife switch. Do not stop the pumps first: the machine must never run without water flow.
  2. Verify the auxiliary oil pump runs during coast-downIt keeps the turbine bearings lubricated until the wheel stops.
  3. Verify the compressor stopped and the oil heater is onThe heater comes on when the compressor stops, keeping refrigerant out of the oil.
  4. Close the manual steam (Gimbal) valveClockwise, fully closed, once the turbine has stopped.
  5. Stop the vacuum pumpsWith no steam flowing the vacuum is no longer needed.
  6. Close the gland seal steam by-pass 1/4-turn valveTake the seal steam off the glands.
  7. Tower fan and condenser-water pump stopThe plant controls stop the tower fan, then the condenser-water pump.
  8. Chilled-water pump stops lastChilled water keeps circulating a little longer after the compressor stops.
  9. Leave the refrigerant valves openSuction, discharge and liquid-line valves stay open unless the machine is being opened for service. Leave the oil heater energized.
  10. Close the condenser-water outlet valveFor an extended shutdown, isolate the condenser from the tower.
  11. Close the condenser-water inlet valve
  12. Close the tower make-up (fill) valveShut off city water to the tower before draining.
  13. Open the basin drain valve and drain the towerDrain the basin so it cannot freeze. (Many plants also drain and vent the condenser for the winter.)
  14. Lock out the tower fanLock and tag the fan motor disconnect so nobody starts it during the lay-up.
  15. Open the chiller knife switchOnly now, with the chiller already stopped by the panel.
  16. Lock and tag the knife switch hoopYour lock and tag on the LOTO hoop.
  17. Record the shutdown in the logTime, reason, readings, and the valve positions you left.

Practice this procedure in 3D

CH-1 refrigerant recovery with the RSR unit Centrifugal (CH-1) · 25 steps

  1. Confirm CH-1 is stoppedStopped with the control panel OFF button. Never recover refrigerant from a running machine.
  2. Put the chilled-water pump HOA in HANDWater must keep flowing through the evaporator tubes: as the refrigerant pressure drops below the freezing point, still water in the tubes would freeze and burst them.
  3. Put the condenser-water pump HOA in HANDCondenser water keeps flowing through the condenser tubes too.
  4. Verify chilled-water flowPressure drop across the evaporator near design and the flow switch closed.
  5. Connect the green (vapor) hoseFrom the condenser service valve (vapor recovery valve #7) to the RSR manifold. Green hose = vapor.
  6. Connect the blue (liquid) hoseFrom the liquid line charging / recovery valve #6 to RSR valve 5. Blue hose = liquid.
  7. Open (back-seat) condenser service valve 7Vapor path between the chiller condenser and the RSR.
  8. Open (back-seat) liquid line valve 6Liquid path from the chiller to the RSR.
  9. Open RSR liquid inlet valve 5
  10. Open RSR manifold valve 1Liquid push: RSR compressor discharge into the chiller condenser.
  11. Open RSR manifold valve 3Liquid push: the RSR compressor draws vapor from the storage tank (receiver). Valves 2 and 4 stay closed.
  12. Turn the RSR ONThe compressor pressurizes the chiller condenser and pushes the liquid out through valve 6 into the storage tank.
  13. Watch the liquid leave the chillerThe evaporator sight glass empties and the storage tank sight glass rises (never past 80%).
  14. Close (front-seat) valve 6Liquid removal is finished: close the liquid valve on the chiller first.
  15. Close RSR valve 5
  16. Open RSR condenser cooling water valves 8 and 9Cooling water must be on before vapor recovery starts: without it the RSR trips on high head pressure.
  17. Line up for vapor: close manifold valves 1 and 3
  18. Line up for vapor: open manifold valves 2 and 4The RSR compressor now pulls vapor out of the chiller (valve 2) and discharges it through its condenser into the storage tank (valve 4).
  19. Recover the vapor to 15 in. Hg vacuumWatch the evaporator gauge fall into vacuum. 15 in. Hg is the EPA recovery level for a medium-pressure (R-134a) appliance holding 200 lb or more.
  20. Close (front-seat) condenser service valve 7
  21. Turn the RSR OFF
  22. Close valves 2, 4, 8 and 9
  23. Disconnect both hosesCap the service ports.
  24. Return the chilled-water pump HOA to AUTO
  25. Return the condenser-water pump HOA to AUTO

Practice this procedure in 3D

CH-3 reciprocating chiller startup (from lay-up) Reciprocating (CH-3) · 28 steps

  1. Check the refrigerant detectorNear zero, no alarm. Never start into an active refrigerant alarm.
  2. Check the compressor 1 crankcase heaterEnergized and drawing 2–3 A (spec sheet). It must have been on long enough to warm the crankcase.
  3. Check the compressor 1 crankcase oil temperature135–150 °F before a start. Below that, refrigerant is dissolved in the oil: do not start.
  4. Check the compressor 1 oil levelOil showing in the sight glasses, no foam.
  5. Check the compressor 2 crankcase heater and oil2–3 A, 135–150 °F, oil showing in the sight glasses.
  6. Discharge service valve · compressor 1: crack it off the back-seatOpen the DISCHARGE valve first. Its normal running position is cracked off the back-seat (open to the line, service port open to the transducer). Never start a compressor with its discharge valve front-seated.
  7. Suction service valve · compressor 1: crack it off the back-seat
  8. Discharge service valve · compressor 2: crack it off the back-seatDischarge first again.
  9. Suction service valve · compressor 2: crack it off the back-seat
  10. Back-seat the system 1 king valveNormal position: back-seated (open). Liquid can now leave the condenser toward the filter-drier, sight glass, solenoid and TXV 1.
  11. Back-seat the system 2 king valve
  12. Check the filter-drier isolation valves are openThe 1/4-turn valves after each filter-drier must be open; the filter-drier service valves stay front-seated.
  13. Close the tower basin drain valve
  14. Open the tower make-up (fill) valve and fill the basinWait for the level to come up.
  15. Inspect the fan belt and driveBelt tight and in good condition, no lock on the disconnect.
  16. Open the condenser water supply (inlet) valve
  17. Open the condenser water return (outlet) valve
  18. Open the chilled water return (inlet) valve
  19. Open the chilled water supply (outlet) valve
  20. Start the chilled-water pump
  21. Verify chilled-water flowEvaporator water pressure drop near design (about 7 psi) and the chilled-water supply flow switch closed.
  22. Start the condenser-water pump
  23. Verify condenser-water flowCondenser water pressure drop near design (about 8 psi) and the condenser return flow switch closed.
  24. Enable the cooling tower fan
  25. Press START on the control panelThe panel proves both flows, starts compressor 1 unloaded and energizes the system 1 solenoid. Compressor 2 starts when more capacity is needed.
  26. Verify net oil pressure (System 1 conditions)Net oil pressure must build well above the 25 psid oil safety setting (about 45–55 psid here) before its time delay runs out.
  27. Check the sight glasses and superheatSight glass full and clear; suction superheat about 8–10 °F on each running system.
  28. Log the readingsSuction and discharge pressures, superheat, subcooling, oil pressure, crankcase temperature, amps and water temperatures for both systems.

Practice this procedure in 3D

CH-3 pump-down and lay-up Reciprocating (CH-3) · 11 steps

  1. Press STOP on the control panelBoth liquid line solenoids de-energize; each compressor keeps running and pumps its system's refrigerant into its condenser.
  2. Watch the pump-downSuction pressure falls until the low suction pressure switch (30 psig) stops each compressor.
  3. Verify both crankcase heaters are onThey stay energized through the whole shutdown (2–3 A each).
  4. Front-seat the system 1 king valveFor an extended shutdown, trap system 1's charge in its condenser.
  5. Front-seat the system 2 king valve
  6. Front-seat both discharge service valvesNow each charge is isolated in its condenser between the discharge service valve and the king valve.
  7. Pumps and tower stopThe plant controls stop the tower fan, then the pumps.
  8. Close the condenser water valves
  9. Close the make-up valve and drain the tower
  10. Lock out the tower fan
  11. Tag the valves and record the shutdownNote which service valves you front-seated so nobody starts the machine against them.

Practice this procedure in 3D

Practice it before exam day. The free trainer runs both systems, a centrifugal and a reciprocating chiller, in your browser, with the same kinds of tasks: operations, repairs, refrigerant handling, troubleshooting, multi-step tasks and scenarios.

Launch the free trainer

Procedure questions

What is the startup procedure for a steam-turbine centrifugal chiller?

In the trainer: check the refrigerant detector, oil temperature, oil level and evaporator refrigerant level; open the compressor suction, discharge and liquid line valves; fill the cooling tower basin, open the water valves and start the chilled-water and condenser-water pumps, verifying flow; then line up the steam side: open the condensate and drip leg valves, fill the hotwell, put the condensate pumps in AUTO, set the gland seal steam, start the vacuum pumps, drain and warm the turbine, check the overspeed trip and turbine oil, open the main steam valve and start from the control panel. The full 43-step list is on this page.

What is a pump-down on a reciprocating chiller?

A pump-down closes the liquid line so the compressor pulls the refrigerant out of the evaporator and stores it in the condenser or receiver before the machine is shut down and laid up. The steps the trainer uses are listed on this page.

Are these the official FDNY procedures?

No. These are the training procedures used in the Refrigeration Practical simulator. Real procedures depend on the equipment manufacturer and your site. Always follow the manufacturer's instructions and your site's procedures.

Disclaimer: Refrigeration Practical is an independent educational tool. It is not affiliated with, endorsed by or connected to the Fire Department of the City of New York (FDNY) or the City of New York. Requirements, fees and exam rules change: always confirm with the official FDNY notice of examination and the FDNY Certificates of Qualification page before you apply.