Specifications

96 Catalog WSC/WDC-4
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 (negative pressure 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 (Negative pressure 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 (negative pressure 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.
B. Adjust chiller alignment on foundations, or subbases as called for on drawings.
C. Arrange piping to allow for dismantling to permit head removal and tube cleaning.
D. Furnish and install necessary auxiliary water piping for oil cooler.
E. Coordinate electrical installation with electrical contractor.
F. Coordinate controls with control contractor.
G. Provide all materiel required for a fully operational and functional chiller.
3.2 START-UP
A. Units shall be factory charged with the proper refrigerant and oil.
B. Factory Start-Up Services: Provide for as long a time as is necessary to ensure proper
operation of the unit, but in no case for less than two full working days. During the period
of start-up, The Start-up Technician shall instruct the Owner’s representative in proper care
and operation of the unit.