Trane Stealth™ Air-Cooled Chiller SCWF72

WARNING: Hazardous Voltage w/Capacitors! Failure to disconnect power and discharge capacitors before servicing could result in death or serious injury.

Disconnect all electric power, including remote disconnects and discharge all motor start/run capacitors before servicing.

Follow proper lockout/tagout procedures to ensure the power cannot be inadvertently energized.

For variable frequency drives or other energy storing components provided by Trane or others, refer to the appropriate manufacturer's literature for allowable waiting periods for discharge of capacitors.

Verify with a CAT III or IV voltmeter rated per NFPA 70E that all capacitors have discharged.

For additional information regarding the safe discharge of capacitors, see PROD-SVB06 *- EN.

The VFD access panel is hinged to allow service access to the fan motor and belt drive components that are located behind it.

Remove the unit center cover panel to the left of the VFD panel.

Remove and discard the sheet metal shipping screws along the top and bottom edges of the VFD panel.

Inspect unit air filters. Clean or replace if airflow is blocked or if filters are dirty.

Inspect coils for excess moisture or icing. Icing on the coils may indicate low airflow supply, restricted airflow from dirty fins, evaporator frost protection sensor problems, or a shortage of refrigerant flowing through the coil.

Check that condensate from the evaporator and economizer coils flows freely through the condensate piping, traps, drain pan, and drainage holes. Remove algae and or any airflow obstructions.

Check the condition and tension of fan belts. Adjust tension if belts are floppy or squeal continually. Replace worn or fraying belts in matched sets.

Note: Check belt tension and adjust it at least twice daily the first days of new belt operation. Belt tension will rapidly decrease until the belts are run in.

Check the liquid line sight glasses during operation. Bubbles in the sight glasses indicate a possible shortage of refrigerant or an obstruction in the liquid lines, e.g. dirty liquid line filter driers.

Inspect filter driers for leaks, flow obstructions, or temperature drop across the filter drier. A noticeable temperature differential, e.g. 5°F, in the liquid line may indicate an obstruction. Replace the filter drier if it appears clogged.

Inspect the optional waterside economizer coil. Clean the coil to prevent airflow restrictions through the fins.

Check and record operating pressures.

Check and tighten all set screws, bolts, locking collars and sheaves

Inspect, clean, and tighten all electrical connections

Visually inspect the entire unit casing for chips or corrosion. Remove rust or corrosion and repaint surfaces

Visually check for leaks in refrigerant piping

Inspect fan, motor, and control contacts. Replace badly worn or eroded contacts

Inspect the thermal expansion valve sensing bulbs for cleanliness, good contact with the suction line, and adequate insulation from ambient air

Verify the superheat setting is 12 -17°F at the compressor

When checking operating pressures and conditions, establish the following nominal conditions for consistent measurements

Leaving air temperature greater than 60°F

NOTICE: Proper Water Treatment Required! The use of untreated or improperly treated water could result in scaling, erosion, corrosion, algae or slime. Use the services of a qualified water treatment specialist to determine what water treatment, if any, is required. Trane assumes no responsibility for equipment failures which result from untreated or improperly treated water, or saline or brackish water.

Condensing water contains minerals that collect on the condenser tube walls. Cooling towers also collect dust and foreign materials that deposit in the condenser tube. The formation of scale or sludge in the condenser is indicated by a decreased water flow, low temperature difference between inlet and outlet water, and abnormally high condensing temperatures.

To maintain maximum condenser efficiency, the condenser must remain free of built-up scale and sludge. Clean the condenser either mechanically or chemically.

Disconnect all electrical power to the unit.

Wear appropriate personal protective equipment (PPE).

Access both sides of the coil section.

Use a soft brush to remove loose debris from both sides of the coil.

Use a steam cleaning machine, starting from the top of the coil and working downward. Clean the leaving air side of the coil first, then the entering air side. Use a block-off to prevent steam from blowing through the coil and into a dry section of the unit.

Repeat step 5 as necessary. Confirm that the drain line is open following completion of the cleaning process.

Hazardous Voltage w/Capacitors!

Failure to disconnect power and discharge capacitors before servicing could result in death or serious injury.

Disconnect all electric power, including remote disconnects and discharge all motor start/run capacitors before servicing. Follow proper lockout/tagout procedures to ensure the power cannot be inadvertently energized. For variable frequency drives or other energy storing components provided by Trane or others, refer to the appropriate manufacturer's literature for allowable waiting periods for discharge of capacitors.

Verify with a CAT III or IV voltmeter rated per NFPA 70E that all capacitors have discharged.

For additional information regarding the safe discharge of capacitors, see PROD-SVB06 *- EN.

Perform the following procedures according to the "Maintenance Periodic Check List":

1. Rotate the fan wheel to ensure it turns freely in the proper direction and is not rubbing on the fan housing or inlet. If necessary, center the fan wheel again.

2. Check the position of both shafts. Fan and motor shafts should operate parallel to each other for maximum belt and bearing life. Shim as necessary under the motor or fan bearings to obtain proper alignment.