RTHD-SVX02H-EN 105
Maintenance Procedures
Cleaning the Condenser
D
CAUTION
Proper Water Treatment!
The use of untreated or improperly treated water in a
RTHD may result in scaling, erosion, corrosion, algae or
slime. It is recommended that the services of a qualied
water treatment specialist be engaged to determine
what water treatment, if any, is required. The Trane
Company assumes no responsibility for equipment fail-
ures which result from untreated or improperly treated
water, 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 wa-
ter temperature) is higher than predicted.
Standard water applications will operate with less than
a 10
°
F approach. If the approach exceeds 10
°
F cleaning
the condenser tubes is recommended.
Note: Glycol in the water system typically doubles the
standard approach.
If the annual condenser tube inspection indicates that
the tubes are fouled, 2 cleaning methods can be used to
rid the tubes of contaminants.The methods are:
Mechanical Cleaning Procedure
Mechanical tube cleaning this method is used to remove
sludge and loose material from smooth-bore condenser
tubes.
1. Remove the retaining bolts from the water boxes
at each end of the condenser. Use a hoist to lift the
water boxes.
2. 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.
3. Thoroughly flush the condenser water tubes with
clean water.
(To clean internally enhanced tubes, use a bi-directional
brush or consult a qualified service organization for rec-
ommendations.)
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/min-
eral 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 ma-
terials or performing the cleaning.
Note: Chemical tube cleaning should always be fol-
lowed 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.
Compressor Oil
D
CAUTION
Equipment Damage!
To prevent oil sump heater burnout, open the unit main
power disconnect switch before removing oil from the
compressor.
Trane Polyolester Oil is the approved oil for the RTHD
units. Polyolester oil is extremely hygroscopic meaning
it readily attracts moisture. The oil can not be stored in
plastic containers due to the hygroscopic properties.
As with mineral oil, if water is in the system it will react
with the oil to form acids. Use Table 33 to determine the
acceptability of the oil.
Table 33. POE Oil Properties
Description Acceptable Levels
Moisture content less than 300 ppm
Acid Level less than 0.3 TAN (mg KOH/g)
Note: Use an oil transfer pump to change the oil regard-
less of chiller pressure.
Oil Sump Level Check
The oil level in the oil sump can be measured to give an
indication of the system oil charge. Follow the proce-
dures below to measure the level.
1. Run the unit fully loaded for approximately 20 min-
utes (Keep leaving evaporator water temperature
lower than 48ºF, entering condenser water tempera-
ture higher than 75ºF) .
Note: Operating the unit at minimum load tends to
lower oil sump levels to as low as 2”, well below
the normal 4.5” to 6.0” levels. This is because the
evaporator tends to hold more oil at minimum
load conditions. Before adding any oil, obtain an
oil level reading near a full load operating condi-
tion.
2. Cycle the compressor off line.
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