Technical data

21
GUIDE SPECIFICATIONS, 1.5 TO 10 TON PROCESS FLUID CHILLER
1.0 GENERAL
1.1 Summary
These specifications describe
requirements for a self-con-
tained air-cooled process fluid
chiller system.
1.2 Design Requirements
The chiller shall be a Liebert
model______, self-contained air-
cooled chiller system. Each sys-
tem shall have a net cooling
capacity of______BTU/HR (kW),
based on a leaving coolant fluid
temperature of_____ °F (°C), and
95°F ambient air temperature.
The cooling fluid shall be____%
propylene glycol, ethylene gly-
col, or water. Unit is to be sup-
plied with ____volts, _____ph,
_____Hz power supply.
1.3 Submittals
Submittals shall be provided
with the proposal and shall
include: Single-line Diagrams;
Dimensional, electrical, and
capacity data; Piping and Elec-
trical Connection Drawings.
2.0 PRODUCT
2.1 Cabinet and Frame
Construction
The cabinet and chassis shall be
constructed of painted weather-
ized steel. Removable access
panels shall open to a second
cover that protects all line volt-
age components. Service access
shall be provided on two sides.
2.2 Coolant Delivery
System
The chiller shall have a factory
installed close-coupled centrifu-
gal pump with a ball bearing
motor designed for continuous
duty. The circulating pump shall
be_____HP and shall have a 304
stainless steel housing and
impeller. The pump shall
provide___GPM (l/m) at___feet
of water (kPa) total head. The
internal coolant delivery system
shall include isolating ball
valves on each side of the pump,
stainless steel thermal storage
reservoir with sight glass, pres-
sure relief valve and optional
heater. The system shall also
include Schrader valve fittings
on each side of the pump and on
each side of the thermal storage
reservoir, and a fixed orifice
bypass to prevent pump “dead
heading”. Internal chilled water
piping shall be factory insulated.
2.3 Refrigeration System
The refrigeration system shall
be direct expansion with fully
insulated shell and coil evapora-
tor. The system shall include
service ports, liquid line filter
dryer, refrigerant sight glass
and moisture indicator. The sys-
tem shall also include an adjust-
able, externally equalized
expansion valve, liquid line sole-
noid valve, and an adjustable
hot gas bypass with a solenoid
valve for compressor capacity
control. The internal condensing
unit shall be factory tested and
charged with refrigerant (R-22)
and shall include a direct-drive
propeller-type fan. The con-
denser coil shall be constructed
of copper tubes and aluminum
fins. The winter control system
shall be a Liebert “Lee-Temp”
system to allow start-up and
positive head pressure control
with ambient temperatures as
low as –30°F (-34.4°C). The Lee-
Temp package shall include
insulated receiver, pressure
relief valve, check valve, and
head pressure three-way control
valve. No piping, brazing, dehy-
dration or charging of the refrig-
eration system shall be
required.
2.4 Compressor
The unit shall have a (hermetic)
(scroll) compressor(s) with suc-
tion gas cooled motor, vibration
isolators, thermal overloads,
crankcase heater, and shall
operate at 3500 RPM @ 60 Hz.
2.5 Control System
The control system shall consist
of a fluid temperature control,
refrigerant pump down low
pressure switch, manual reset
high pressure switch, low ambi-
ent start relay, compressor anti-
recycle relay set for three min-
utes, 24 volt transformer with
circuit breaker, and remote shut
down terminals for unit shut-
down via a maintained NC con-
tact. The line voltage system
shall include pump contactor,
pump overload relay, compres-
sor/fan contractors, and starters.
3.0 OPTIONAL
E
QUIPMENT
3.1 Refrigerant Gauges
and Reservoir Heater
The refrigerant gauges and res-
ervoir heater shall be factory
installed. The reservoir heater
shall maintain minimum fluid
temperature during low ambi-
ent conditions and shall be a
250-watt, copper sheath/stain-
less steel plug insertion type
heater with integral adjustable
thermostat for the fluid reser-
voir. The adjustable thermostat
shall be set to turn on at 35°F
(1.7°C) and turn off at 42°F
(5.6°C). The suction and dis-
charge refrigerant gauges shall
be 2 ½ inches (63.5 mm) in
diameter, hermetically sealed,
with stainless steel bourdon
tube and stainless steel housing.
3.2 Multistage Pump
(option on 8- and
10-ton models)
Chiller shall include a 6-stage
2 Hp pump capable of delivering
____ GPM at _____ Ft. of Total
Head.