Trane Cold Generator, Installation, Operation And Maintenance Manual

CG-SVX038A-EN

19 

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 

Figure 3, p. 21

 for chilled 

water piping schematic and 

Figure 4, p. 22

 for condenser 

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.

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. 23

. Condenser pressure 

drop curves are shown in 

Table 6, p. 23

.

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 

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

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.

Chilled Water Piping

Chilled water piping and associated components shall be 
installed in accordance with 

Figure 3, p. 21

. Chilled water 

inlet and outlet types, sizes and locations are provided in 

Table 4, p. 12

 and 

Table 5, p. 14

. Chilled water piping must 

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 

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.

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.

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.