Quantech QWC3050T-200T, Installation Operation & Maintenance

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FORM QWC3-NM1
ISSUE DATE: 11/20/2020
SECTION 2 – PRODUCT DESCRIPTION
QUANTECH
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Discharge lines include service and isolation (ball)
valves, two high-pressure cutout switches, a pressure
transducer and a pressure relief valve.
EVAPORATOR
The dual-circuit evaporator will be the direct-expan-
sion type, with refrigerant in the tubes and chilled
liquid flowing through the baffled shell. The design
working pressure of the shell (liquid) side will be 150
PSIG (10.3 bar), and 400 PSIG (27.6 bar) for the tube
(refrigerant) side. The refrigerant side is protected by
pressure relief valve(s).
The evaporator shall have water pass baffles fabricated
from galvanized steel to resist corrosion. Removable
heads are provided for access to internally enhanced,
seamless, copper tubes. Water vent and drain connec-
tions are included. The cooler is insulated with 3/4”
(19mm) flexible closed-cell foam.
Water Connection to the evaporator is via ANSI/
AWWA C-606 grooved connections. Flange connec-
tions are available as an option. The shell will be con-
structed and tested in accordance with Section VII, Di-
vision 1 of the ASME Pressure Vessel Code. The water
side is exempt per paragraph U-1 (ºC) of Section VII,
Division 1 of the ASME Pressure Vessel Code.
The evaporator is constructed and tested in accordance
with applicable sections of the ASME Pressure Vessel
Code, Section VIII, Division (1). The water side will
be exempt per paragraph U-1, (ºC) (6).
A strainer with a mesh size between .5 and 1.5 mm (40
mesh) is recommended upstream of the evaporator to
prevent clogging.
CONDENSER
The dual refrigerant circuit water-cooled condenser is
a cleanable shell and tube type with seamless external
finned copper tubes rolled into tube sheets. The design
working pressures are 150 PSIG (10.3 barg), integral
subcooling is part of the design on the waterside and
560 PSIG (38.6 barg) on the refrigerant side which is
protected by pressure relief valve(s).
The condenser has removable steel water heads. The
water nozzles are provided with grooves for victualic
couplings.
The shell is constructed and tested in accordance with
Section VII, Division 1 of ASME Pressure Vessel
Code. The water side is exempt per paragraph U-1, (C),
(6) of Section VII, Division 1 of ASME Pressure Ves-
sel Code. The condenser is equipped with relief valves
and will hold the full refrigerant charge for pumpdown.
REFRIGERANT CIRCUIT
Two independent refrigerant circuits will be furnished
on each unit. All piping will be copper with brazed
joints. The liquid line will include: a shutoff valve
with charging port; sight-glass with moisture indicator;
thermal expansion valve; solenoid valve; and high ab-
sorption removable-core filter drier. The entire suction
line and the liquid line between the expansion valve
and the cooler will be insulated with flexible, closed-
cell, foam insulation.
MICROPROCESSOR CONTROL CENTER
All controls and motor starting equipment necessary
for unit operation are factory wired and function tested.
The panel enclosures are designed to NEMA 1 (IP 32)
and manufactured from powder-painted galvanized
steel.
• Two character Liquid Crystal Display with Light
Emitting Diode backlighting for outdoor viewing:
• Two display lines
• Twenty characters per line
• Color coded 12-button non-tactile keypad with
sections for:
• Control supply fuses and connections for a
remote emergency stop device.
• ON/OFF rocker switch, microcomputer
keypad and display, microprocessor board,
I/O expansion board, relay boards, and 24V
fused power supply board.
• Customer terminal block for control inputs
and liquid flow switch.
The microprocessor control includes:
• Automatic control of compressor start/stop, an-
ticoincidence and anti-recycle timers, automatic
pumpdown on shutdown, evaporator pump and
unit alarm contacts. Automatic reset to normal
chiller operation after power failure.
• Remote water temperature reset via a pulse width
modulated (PWM) input signal or up to two steps
of demand (load) limiting.
• Software stored in non-volatile memory
(EPROM), with programmed setpoints retained in
a lithium battery backed Real Time Clock (RTC)
memory for a minimum of five years.
• Forty character liquid crystal display, with de-
scription available in five languages (English,
French, German, Spanish or Italian).