Unit Piping - Trane Cold Generator CGWR Series Installation, Operation And Maintenance Manual

Unit Piping

Water Piping — General
Make water piping connections to the evaporator and
condenser (CGWR only). Isolate and support piping to
prevent stress on the unit. Use unions, flanges or grooved
lock type fittings to simplify disassembly and facilitate
service procedures. Use vibration eliminators to prevent
transmitting vibrations to the water lines. Install
thermometers in the lines to monitor evaporator and
condenser water temperatures. Install balancing cocks in
both the leaving chilled water and condenser water lines.
These valves can be used to establish a balanced water
flow. Entering and leaving chilled and condenser water
lines should have shutoff valves installed to isolate the
heat exchanger for service. See
water piping schematic and
water piping schematic.
Do not overtighten connections. Use a pipe sealant such as
®
Teflon tape on all threaded water connections. Flush all
piping before attaching to the unit. Unit MUST be
bypassed if using a flushing agent.
NOTICE:
Equipment Damage!
To prevent equipment damage, you MUST follow
instructions below:
• Bypass unit if using a flushing agent.
• Chilled water piping must rise above the chiller to
insure the evaporator is full of water and void of air at
all times.
• Do not overtighten connections.
Piping and specialties must be installed in accordance
with national and local codes.
Water Flow Rates
Establish balanced water flow through both the
evaporator and condenser. Flow rates should fall between
the minimum and maximum values given in General Data
Table 1 and Table 2, p. 7. Flow rates above or below these
values can cause equipment damage or improper unit
operation. Measure the evaporator and condenser water
pressure drop at the gauge ports located adjacent to the
heat exchanger, before any piping specialty components,
such as wye strainer. Evaporator water pressure drop
curves are shown in Table 5, p.
drop curves are shown in
Optional inlet wye strainer has an outlet port that can be
used for measuring inlet evaporator water pressure, if it is
installed immediately adjacent to the evaporator inlet.
Note: Evaporator and condenser pressure drop
measurement is for an approximation and is to be
used as a tool to estimate flow rate and as an aid in
CG-SVX038A-EN
Figure 3, p. 21 for chilled
Figure 4, p. 22 for condenser
23. Condenser pressure
Table 6, p. 23.
waterside system design. If an accurate
measurement of flow rate is required, an accurate
flow measurement device must be installed in the
water line.
Water Treatment
NOTICE:
Proper Water Treatment Required
The use of untreated or improperly treated water in this
unit 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.
Using untreated or improperly treated water in these units
may result in inefficient operation and possible tube and/
or brazed plate damage. Consult a qualified water
treatment specialist to determine if treatment is needed.
NOTICE:
Waterborne Debris!
To prevent evaporator or condenser damage,
evaporator and condenser strainers must be installed in
the water supplies to protect components from water
born debris. Removal of wye strainer or screen will void
the warranty on the brazed plate evaporator.
Chilled Water Piping
Chilled water piping and associated components shall be
installed in accordance with
inlet and outlet types, sizes and locations are provided in
Table 4, p. 12 and Table 5, p.
rise above the chiller to ensure the evaporator is full of
water and void of air at all times. All chilled water lines
must be insulated to minimize heat gain and prevent
condensation.
Brazed Plate Evaporator
Trane CGWR/CCAR chillers are equipped with brazed plate
evaporators made of stamped stainless steel plates,
furnace brazed together with copper to form a durable
high efficiency heat exchanger. Because of the small
complex geometry of the flow passages, it is imperative
customers take all precautions to ensure these
evaporators are not fouled by large particles or internal
mineral deposits. For this reason, a 20 mesh wye strainer
is required in the inlet chilled water line. Operation of the
chiller without this wye strainer or the wye strainer 20
mesh screen will void the chiller warranty. Chemical
Figure 3, p. 21. Chilled water
14. Chilled water piping must
19