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Water-Cooled Helical Rotary Chiller Series R: Annual Maintenance and Checks

Annual maintenance is a simple and cost-effective way to ensure your HVAC system is running at peak efficiency and to catch problems before they get serious.

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08/10/2022

Water-Cooled Helical Rotary Chiller Series R: Annual Maintenance and Checks

Annual maintenance is a simple and cost-effective way to ensure your HVAC system is running at peak efficiency and to catch problems before they get serious.

Overview

An important aspect of the chiller maintenance program is the regular completion of operator logs. See “Log and Check Sheets,” p. 157 for an example. When filled out properly the completed logs can be reviewed to identify any developing trends in the chiller's operating conditions

This section describes preventative maintenance procedures and intervals. Use a periodic maintenance program to ensure optimal performance and efficiency of the Series R units.

Maintenance

! WARNING

Hazardous Voltage!

Failure to disconnect power before servicing could result in death or serious injury. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized.

! WARNING

Live Electrical Components!

Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury. When necessary to work with live electrical components, have a qualified licensed electrician or other individual who has been properly trained in handling live electrical components perform these tasks.

Annual Maintenance and Checks

! WARNING

Hazardous Voltage!

Failure to disconnect power before servicing could result in death or serious injury. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized.

Shut down the chiller once each year to check the following:

https://www.trane.com/content/dam/Trane/Commercial/global/products-systems/equipment/chillers/water-cooled/helical-rotary/RLC-SVX09L-EN_06122020.pdf

Perform all weekly and monthly maintenance procedures
Have a qualified laboratory perform an oil analysis to determine system moisture content and acid level.
Note: Due to the hygroscopic properties of the POE oil, all oil must be stored in metal containers. The oil will absorb water if stored in a plastic container.
Contact Trane service organization to leak check the chiller, to inspect safety controls, and inspect electrical components for deficiencies.
Inspect all piping components for leakage and/or damage. Clean out any inline strainers.
Clean and repaint any areas that show signs of corrosion.
Inspect vent piping of all relief valves for presence of refrigerant to detect improperly sealed relief valves. Contact Trane service if unusual conditions are observed.
Inspect the condenser tubes for fouling. Clean if necessary. See “Cleaning the Condenser (RTWD Only),” p. 130.
Check to make sure that the crank case heater is working.

Scheduling Other Maintenance

Use a nondestructive tube test to inspect the condenser and evaporator tubes at 3-year intervals.

Note: It may be desirable to perform tube tests on these components at more frequent intervals, depending upon chiller application. This is especially true of critical process equipment.

Depending on chiller duty, contact a qualified service organization to determine when to conduct a complete examination of the unit to determine the condition of the compressor and internal components.

Refrigerant and Oil Charge Management

Proper oil and refrigerant charge is essential for proper unit operation, unit performance, and environmental protection. Only trained and licensed service personnel should service the chiller.

Table 85and Table 86 list baseline measurements for units running at AHRI standard operating conditions. If chiller measurements vary significantly from values listed below, problems may exist with refrigerant and oil charge levels. Contact Trane service.

TABLE 85

TABLE 86

Note: AHRI conditions are: condenser water: 85°F and 3 GPM per ton and evaporator water: 54-44°F

Heat Exchanger Service

Cleaning the Condenser (RTWD Only)

NOTICE:

Proper Water Treatment!

The use of untreated or improperly treated water could result in scaling, erosion, corrosion, algae or slime. It is recommended that the services of a qualified water treatment specialist be engaged 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.

Condenser tube fouling is suspect when the “approach” temperature (i.e., the difference between the refrigerant condensing temperature and the leaving condenser water temperature) is higher than predicted.

Standard water applications will operate with less than a 10oF approach. If the approach exceeds 10oF cleaning the condenser tubes is recommended.

Note: Glycol in the water system may as much as double the standard approach.

If the annual condenser tube inspection indicates that the tubes are fouled, two cleaning methods can be used to rid the tubes of contaminants.

Mechanical tube cleaning method is used to remove sludge and loose material from smooth-bore condenser tubes. See “Mechanical Cleaning Procedure,” p. 131.

Chemical cleaning procedures are used to remove scale deposits. See “Chemical Cleaning Procedure,” p. 133

Mechanical Cleaning Procedure

! WARNING

Heavy Objects!

Failure to properly lift waterbox/cover could result in death or serious injury. Each of the individual cables (chains or slings) used to lift the waterbox/cover must be capable of supporting the entire weight of the waterbox/cover. The cables (chains or slings) must be rated for overhead lifting applications with an acceptable working load limit.

! WARNING

Heavy Objects!

Failure to properly lift waterbox could result in death or serious injury. The proper use and ratings for eyebolts can be found in ANSI/ASME standard B18.15. Maximum load rating for eyebolts are based on a straight vertical lift in a gradually increasing manner. Angular lifts will significantly lower maximum loads and should be avoided whenever possible. Loads should always be applied to eyebolts in the plane of the eye, not at some angle to this plane.

Review mechanical room limitations and determine the safest method or methods of rigging and lifting the waterboxes.

Units with Standard Condenser Waterboxes.

Select the proper waterbox removal procedure method as shown below.

Waterbox Removal Procedure

This selection applies to the units and condenser side waterboxes shown in Table 88.

METHOD 1:

Select the proper lift connection device from Table 91. The rated lifting capacity of the selected lift connection device must meet or exceed the published weight of the waterbox. See Table 87, p. 131 for waterbox weights.
Ensure the lift connection device has the correct connection for the waterbox. Example: thread type (course/fine, English/metric). Bolt diameter (English/ metric).
Properly connect the lift connection device to the waterbox. See Figure 72. Ensure lift connection device is securely fastened.
Install hoist ring on to the lifting connection on the waterbox. Torque to 28 ft-lbs (37 Nm).
Disconnect water pipes, if connected.
Remove waterbox bolts.
Lift the waterbox away from the shell.

METHOD 2:

This selection applies to the units and condenser side waterboxes shown in Table 89.

! CAUTION

Risk of Injury!

To prevent injury, do not place hands or fingers between waterbox and condenser tubesheet.

Select the proper lift connection device from Table 91, p. 133. The rated lifting capacity of the selected lift connection device must meet or exceed the published weight of the waterbox. See Table 87, p. 131 for waterbox weights.

Ensure the lift connection device has the correct connection for the waterbox. Example: Thread type (course/fine, English/metric), Bolt diameter (English/metric).

Disconnect water pipes, if connected.

Remove the two bolts with drill point mark. Install the long bolts into these two holes until threads are fully engaged, and hand tight. The long bolts are located on the two thread holes just above the waterbox, as shown in Figure 73.

Remove the remaining bolts. Slide the waterbox out about 30 mm through two long bolts. Install the Safety Hoist ring (D ring) connection device into the tap drill hole located on waterbox right side (face to waterbox convex). See Figure 74.

Remove the left long bolt while supporting waterbox from outside of waterbox. Swing the waterbox outboard. Put lifting chain on Safety Hoist ring and remove the remaining long bolt. See Figure 75.

Lift the waterbox away from the shell.

! WARNING

Overhead Hazard!

Never stand below or in close proximately to heavy objects while they are suspended from, or being lifted by, a lifting device. Failure to follow these instructions could result in death or serious injuries.

Condenser Tube Cleaning - Mechanical

Store waterbox/cover in a safe and secure location and position.
Important: Do not leave waterbox/cover suspended from lifting device.
Work a round nylon or brass bristled brush (attached to a rod) in and out of each of the condenser water tubes to loosen the sludge.
Thoroughly flush the condenser water tubes with clean water.
Note: To clean internally enhanced tubes, use a bidirectional brush or consult a qualified service.

Reassembly. Once service is complete, the waterbox/ cover should be reinstalled following all previous procedures in reverse.

Use new o-rings or gaskets on all joints after thoroughly cleaning each joint. Contact local Trane parts center for information.

Torque waterbox/cover bolts.

Note: Torque bolts in a star pattern. See Table 90 for torque values.

Parts Ordering Information.

Chemical Cleaning Procedure

Scale deposits are best removed by chemical means. Consult a qualified water treatment specialist (i.e., one that knows the local water supply chemical/mineral content) for a recommended cleaning solution suitable for the job. (A standard condenser water circuit is composed solely of copper, cast iron and steel.) Improper chemical cleaning can damage tube walls.

All of the materials used in the external circulation system, the quantity of the solution, the duration of the cleaning period, and any required safety precautions should be approved by the company furnishing the materials or performing the cleaning.

Note: Chemical tube cleaning should always be followed by mechanical tube cleaning.

Cleaning the Evaporator

Since the evaporator is typically part of a closed circuit, it does not accumulate appreciable amounts of scale or sludge. However, if cleaning is deemed necessary, use the same cleaning methods described for the condenser tubes.

See Table 92, p. 134 for evaporator waterbox weights.

RTUD Air Cooled Condenser Applications

High Condenser Pressure Limit and High Pressure Cutout Diagnostics

If a circuit experiences significant time in the High Condenser Pressure Limit mode, or if it experiences High Pressure Cutout trip diagnostics, the air cooled condenser may be the root cause and should be inspected.

The condenser coils should be checked for air flow restrictions and cleanliness, as well as the possibility of recirculated air, in which the air entering the coil is significantly higher temperature than the ambient outdoor air temperature (5 ºF or more).

All of the fans should also be validated to be operational with the proper fan blade rotation direction. Dirty, or fouled coils, or otherwise limited or restricted air flow through the coils, can significantly degrade the efficiency of the chiller as well as result in unnecessary limits and nuisance trips. See the condenser manufacturers’ maintenance and cleaning procedures.

Lubrication System

Compressor Oil