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SECTION 2 – PRODUCT DESCRIPTION
Condenser
Coils – Fin and tube condenser coils of seamless, in-
ternally-enhanced, high-condensing-coefficient, corro-
sion resistant copper tubes are arranged in staggered
rows, mechanically expanded into aluminum fins. Inte-
gral subcooling is included. The design working pres-
sure of the coil is 650 PSIG (45 bar).
Fans – The condenser fans are composed of corro-
sion-resistant aluminum hub and glass-fiber-reinforced
polypropylene composite blades molded into a low
noise airfoil section. They are designed for maximum
efficiency and are statically and dynamically balanced
for vibration free operation. They are directly driven by
independent motors, and positioned for vertical air dis-
charge. The fan guards are constructed of heavy-gauge,
rust-resistant, coated steel. All blades are statically and
dynamically balanced for vibration-free operation.
Motors – The fan motors are Totally Enclosed Air-
Over, squirrel-cage type, current protected. They fea-
ture ball bearings that are double-sealed and perma-
nently lubri cated.
REFRIGERANT CIRCUIT
Two inde pendent refrigerant circuits will be furnished
on each unit. All unit piping will be copper, with brazed
joints. The liquid line will include a field connection
shutoff valve with charg ing port located on each con-
denser circuit. Suction line connections are provided
on each refrigeration circuit. A filter drier and sight
glass are shipped loose for field installation on each
refrigerant circuit.
All expansion valves, liquid line solenoid valves,
refriger ant, and refrigerant field piping are supplied by
others.
MICROCOMPUTER CONTROL CENTER
All controls are contained in a NEMA 3R/12 cabinet
with hinged outer door and include:
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 sec-
tions for:
16
DISPLAY/PRINT of typical information:
• Suction temperatures (optional)
• Ambient temperature
• System pressures (each circuit)
• Operating hours and starts (each compressor)
• Print calls up to the liquid crystal display
• Operating data for the systems
• History of fault shutdown data for up to the last
six fault shutdown conditions.
• An RS-232 port, in conjunction with this press-to-
print button, is provided to permit the capability
of hard copy print-outs via a separate printer (by
others).
ENTRY section to:
ENTER setpoints or modify system values SETPOINTS
updating can be performed to:
• Suction pressure setting
• Suction pressure control zone
• Remote reset temperature range
• Set daily schedule/holiday for start/stop
• Manual override for servicing
• Low and high ambient cutouts
• Number of compressors
• Low suction pressure cutout
• High discharge pressure cutout
• Anti-recycle timer (compressor start
cycle time)
• Anti-coincident timer (delay compressor starts)
UNIT section to:
• Set clock
• Set options
• Set unit option
Set unit control for Discharge Air Temperature Control
or for Suction Pressure Control (requires Suction Pres-
sure Transducers – standard.
UNIT ON/OFF switch
The microprocessor control center is capable of
display ing the following:
• Suction temperatures (optional)
FORM 150.73-NM2
ISSUE DATE: 09/07/2020
JOHNSON CONTROLS
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