Trane Stealth™ Air-Cooled Chiller SCWF72

Verify the fan motor is properly lubricated

Note: The bearings are manufactured using a special synthetic lithium-based grease designed for long life and minimum lube intervals. Over lubrication can be just as harmful as not enough.

With power disconnected, manually rotate the fan wheel to check for obstructions in the housing or interference with fan blades. Remove obstructions and debris. Center the fan wheel if necessary.

Check the fan assembly sheave alignment. Tighten set screws to their proper torques.

Check water valves for leakage at valve stem packing nut.

Note: Perform this procedure monthly if the unit is in a coastal or corrosive environment.

Sign off on the 6 Monthly Stealth™ Air-Cooled Chiller Maintenance

Warning: This procedure requires trained personnel with PPE!

Measure belt span between centers of sheaves

Set the large 'O' ring of the tensioning gauge at 1/64 inch for each inch of belt span

Is the large 'O' ring even with the top of the belt line or the next belt?

Note the number on the plunger scale after removing the gauge

Does the reading from step 5 match the values given in the manual?

Sign off on the belt tension maintenance

NOTICE: Do not over-tension belts as it could reduce fan and motor bearing life, accelerate belt wear and possibly cause shaft failure.

Loosen bolts A, B, and E on both sides of the sliding motor base. See Figure 43, p. 90.

Loosen nuts C and D (as required for motor horsepower) to slide the motor on its mounting plate in the proper direction to tension or relieve tension on the belt.

Adjust nuts A-D and bolt E. Do not stretch the belts over the sheaves.

Verify tension is adjusted properly.

Recommended belt tension range values are on the unit fan scroll. To access the fan scroll, face the righthand side of the unit and remove the top left panel. The belt tension label is on the top right-hand corner of the fan scroll. See Figure 43, p. 90

The correct operation tension for a V-belt drive is the lowest tension at which the belt will not slip under the peak load conditions. It may be necessary to increase the tension of some drives to reduce flopping or excessive startup squealing.

Sign off on the belt tension adjustment

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.