York YCAL0041 - Manual (Page 75)

YORK INTERNATIONAL 75
FORM 150.64-EG1
2. Refrigerant flow through the compressor with 100%
suction cooled motor.
3. Large suction side free volume and oil sump to
provide liquid handling capability.
4. Compressor crankcase heaters to provide extra
liquid migration protection.
5. Annular discharge check valve and reverse vent
assembly to provide low pressure drop, silent shut-
down and reverse rotation protection.
6. Initial Oil charge.
7. Oil Level sightglass.
8. Vibration isolator mounts for compressors.
9. Brazed-type connections for fully hermetic refrig-
erant circuits.
2.03 REFRIGERANT CIRCUIT COMPONENTS
Each refrigerant circuit shall include: liquid line shutoff
valve with charging port, low side pressure relief device,
filter-drier, solenoid valve, sight glass with moisture indi-
cator, expansion valves, and flexible, closed-cell foam
insulated suction line.
2.04 HEAT EXCHANGERS
A. Evaporator:
1. Evaporator shall be brazed-plate stainless
steel construction, single or dual circuit heat
exchangers capable of refrigerant working
pressure of 450 psig (3103 kPa) and
liquid side pressure of 150 psig (1034 kPa)
(Option for 300 psig [2068 kPa] available.)
2. Evaporator shall be covered in 3/4" (19mm)
flexible, closed cell insulation, thermal conduc
tivity of 0.26k (BTU/HR-FT 2- °F]/in.) maximum.
3. C o o l e r s h a l l h a v e t h e r m o s t a t i
cally controlled heaters to protect to -20°F
(29°C) ambient in off-cycle.
4. Brazed plate heat exchangers shall be UL
listed.
5. Installing contractor must include accomoda
tions in the chilled water piping to allow prop
er drainage and venting of the heat exchang
er. A strainer with a mesh size between 0.5
and 1.5mm (40 mesh) is recommended up
stream of the heat exchanger to prevent clog
ging.
B. Air Cooled Condenser:
1. Coils: Internally enhanced, seamless copper
tubes, mechanically expanded into aluminum
alloy fins with full height collars. Subcooling coil
an integral part of condenser. Design working
pressure shall be 450 PSIG (31 bar).
2. Low Noise Fans: Shall be dynamically and
statically bal anced, direct drive, corrosion re
sistant glass fiber reinforced composite blades
molded into a low noise, full-airfoil cross section,
providing vertical air discharge and low
sound. Each fan in its own compartment
to prevent crossflow d u r i n g f a n
cycling. Guards of heavy gauge, P V C
(polyvinylchloride) coated or galvanized
steel.
3. Fan Motors: High efficiency, direct drive, 6 pole,
3 phase, insulation class “F”, current protected,
Totally Enclosed Air-Over (TEAO), rigid
mounted, with double sealed, permanently lu-
bricated, ball bearings.
2.05 CONTROLS
A. General: Automatic start, stop, operating, and pro-
tection sequences across the range of scheduled
conditions and transients.
B. Microprocessor Enclosure: Rain and dust tight
NEMA 3R/12 (IP55) powder painted steel cabinet
with hinged, latched, and gasket sealed door.
C. Microprocessor Control Center:
1. Automatic control of compressor start/stop,
anti-coincidence and anti-recycle timers, au-
tomatic pumpdown on shutdown, condenser
fans, evaporator pump, evaporator heater, unit
alarm contacts, and chiller operation from 0°F
to 125°F (-18°C to 52°C) ambient. Automatic
reset to normal chiller operation after power
failure.
2. Remote water temperature reset via a Pulse
Width Modulated (PWM) input signal or up to
two steps of demand (load) limiting.
3. Software stored in non-volatile memory, with
programmed setpoints retained in lithium bat-
tery backed real time clock (RTC) memory for
minimum 5 years.
4. Forty character liquid crystal display, descrip-
tions in English (or Spanish, French, Italian, or
German), numeric data in English (or Metric)
units. Sealed keypad with sections for Setpoints,
Display/Print, Entry, Unit Options & clock, and
On/Off Switch.
5. Programmable Setpoints (within Manufacturer
limits): display language; chilled liquid tempera-
ture setpoint and range, remote reset tempera-
ture range, set daily schedule/holiday for start/
stop, manual override for servicing, low and high
ambient cutouts, number of compressors, low