Product Manual PM WSC/WDC 79
2.5. MISCELLANEOUS ITEMS
A. Pumpout System: The unit shall be equipped with a pumpout system complete with a transfer
pump, condensing unit, and storage vessel constructed according to ASME Code for Unfired
Pressure Vessels and shall bear the National Boards stamp. If the design of the unit allows
the charge to be transferred to and isolated in the main condenser, then a pumpout system is
not required. Transfer of refrigerant charge shall be accomplished by either main compressor
operation, migration, or gravity flow. Isolation shall be accomplished with valves located at
the inlet and exit of the condenser. The main condenser shall be sized to contain the
refrigerant charge at 90°F according to ANSI-ASHRAE 15.A.
B. Purge System (HCFC-123 Chillers Only):
1. The chiller manufacturer shall provide a separate high efficiency purge system that
operates independently of the unit and can be operated while the unit is off. The
system shall consist of an air-cooled condensing unit, purge condensing tank,
pumpout compressor and control system.
2. A dedicated condensing unit shall be provided with the purge system to provide a
cooling source whether or not the chiller is running. The condensing unit shall
provide a low purge coil temperature to result in a maximum loss of 0.1 pounds of
refrigerant per pound of purged air.
3. The purge tank shall consist of a cooling coil, filter-drier, water separation tube, sight
glass, drain, and air discharge port. Air and water are separated from the refrigerant
vapor and accumulated in the purge tank.
4. The pumpout system shall consist of a small compressor and a restriction device
located at the pumpout compressor suction connection.
5. The purge unit shall be connected to a 100% reclaim device.
C. Vacuum Prevention System (HCFC-123 Chillers Only): Chiller manufacturer shall supply and
install a vacuum prevention system for each chiller. The system shall constantly maintain 0.05
psig inside the vessel during non-operational periods. The system shall consist of a precision
pressure controller, two silicon blanket heaters, a pressure transducer, and solid-state safety
circuit.
D. Refrigerant Detection Device (HCFC-123 Chillers Only): Chiller manufacturer shall supply and
install a refrigerant detection device and alarm capable of monitoring refrigerant at a level of 10
ppm. Due to the critical nature of this device and possible owner liability, the chiller
manufacturer shall guarantee and maintain the detection monitor for five years after owner
acceptance of the system.
E. Waffle type vibration pads for field mounting under unit feet.
PART 3 — EXECUTION
3.1 INSTALLATION
A. Install per manufacturer’s requirements, shop drawings, and Contract Documents.
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