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conditions. If chiller measurements vary significantly from
values listed below, problems may exist with refrigerant
and oil charge levels. Contact Trane service.
Table 19. Operating conditions at full load
Description
Evaporator pressure
Condensing pressure
Discharge superheat
Subcooling
EXV percent open
(a) All conditions stated above are based on the unit running fully loaded
at AHRI conditions. If full load conditions cannot be met, contact Trane
service.
Table 20. Operating conditions at minimum load
Description
Condition
Evaporator approach
*less than 7
Condensing approach
*less than 7
Subcooling
2-3
EXV percent open
10-20 % open
*
1.0
o
F for new unit.
(a) Conditions at minimum must be: entering condenser water: 85F and entering
evaporator water: 55F
Maintenance Procedures
Cleaning the Condenser
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.
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
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, two cleaning methods can be used to rid
the tubes of contaminants.The methods are:
RTHD-SVX01K-EN
(a)
Condition
40-55 psig
85-120 psig
17
o
F
5-10
o
F
40-50% open in Auto mode
(a)
o
F (non-glycol applications)
o
F
o
F
Mechanical Cleaning Procedure
Mechanical tube cleaning this method is used to remove
sludge and loose material from smooth-bore condenser
tubes.
WARNING
Heavy Objects!
Failure to properly lift waterbox could result in death or
serious injury. Each of the individual cables (chains or
slings) used to lift the waterbox must be capable of
supporting the entire weight of the waterbox. The
cables (chains or slings) must be rated for overhead
lifting applications with an acceptable working load
limit.
WARNING
Straight Vertical Lift Required!
Failure to properly lift waterbox in straight vertical lift
could cause the eyebolts to break which could result in
death or serious injury from object dropping.
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.
Waterbox Removal.
Review mechanical room
limitations and determine the safest method or methods
of rigging and lifting the waterboxes.
Important:
•
Do not rotate water boxes. See
Figure 16, p. 32
for correct orientation of the water inlet
and outlet.
•
Be certain to replace water boxes right-side-up to
maintain proper baffle orientation. Use new o-rings.
1. Determine the size of chiller being serviced. See unit
nameplate located on chiller control panel.
2. Select the proper lift connection device from
p.
70. The rated lifting capacity of the selected lift
connection device must meet or exceed the published
weight of the waterbox found in
3. Ensure the lift connection device has the correct
connection for the waterbox. Example: thread type
(course/fine, English/metric). Bolt diameter (English/
metric).
4. Properly connect the lift connection device to the
waterbox. See
Figure
39. Ensure lift connection device
is securely fastened.
5. Install hoist ring on to the lifting connection on the
waterbox. Torque to 28 ft-lbs (37 Nm).
Maintenance
Figure 14, p. 31
through
Table 23,
Table 22, p.
70.
69
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