York YLAA Operation Manual page 57

Guide Specifications (Cont'd)
JOHNSON CONTROLS
3. High Ambient Control: Allows units to operate when the ambient temperature is
above 115°F (46°C). Includes discharge pressure transducers.
2.02 COMPRESSORS
A. Compressors: Shall be hermetic, scroll-type, including:
1. Compliant design for axial and radial sealing
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 shutdown and reverse rotation protection.
6. Initial oil charge.
7. Oil level sight glass.
8. Vibration isolator mounts for compressors.
9. Brazed-type connections for fully hermetic refrigerant circuits.
10. Compressor Motor overloads capable of monitoring compressor motor current. Pro-
vides extra protection against compressor reverse rotation, phase-loss and phase-
imbalance
2.03 REFRIGERANT CIRCUIT COMPONENTS
Each refrigerant circuit shall include: a discharge service ball type isolation valve, high
side pressure relief, liquid line shutoff valve with charging port, low side pressure relief
device, filter-drier, solenoid valve, sight glass with moisture indicator, thermostatic expan-
sion valves [Option: electronic expansion valves], and flexible, closed-cell foam insulated
suction line and suction pressure transducer.
2.04 HEAT EXCHANGERS
A. Evaporator :
1. Evaporator shall be brazed-plate stainless steel construction capable of refrigerant
working pressure of 450 psig (3103 kPa) and liquid side pressure of 150 psig (1034
kPa).
2. Brazed plate heat exchangers shall be UL listed.
3. Exterior surfaces shall be covered with 3.4" (19mm), flexible, closed cell insulation,
thermal conductivity of 0.26k ([BTU/ HR-Ft2 -°F]/in.) maximum.
4. Water nozzles shall be provided with grooves for field provided ANSI/AWWA C-606
mechanical couplings.
5. Evaporator shall include vent and drain fittings and thermostatically controlled heat-
ers to protect to -20°F (-29°C) ambient in off-cycle.
FORM 150.72-EG6 (516)
57