Application Data - York YPC Engineering Manual

Application Data

The following discussion is a user guide in the applica-
tion and installation of YPC Absorption Steam Chillers to
en sure the reliable, trouble-free life for which this equip-
ment was designed. While this guide is directed towards
normal water-chilling applications, you local Johnson
Controls sales representative can provide complete rec-
ommendations on other types of applications.
LOCATION
YPC units make very little noise or vibration and may
be generally located at any level in a building where the
construction will support the total system operating weight.
The unit site should be a floor, mounting pad or foundation
which is level and capable of supporting the operating
weight of the YPC chiller. The YPC unit will operate prop-
erly and produce maximum output only if it is installed level
within 1/1000 of the unit length in the lengthwise direction
and 1/1000 of unit width in the widthwise direction.
Leave between 46 and 60 inches (1.17-1.52 meters) of
space around the machine for servicing, reading instru-
ments, and per forming tests. If there are flammable ma-
terials near the machine, leave at least 20 inches (0.5 m)
of space above the machine and at least 40 inches (1.02
m) above the first-stage generator. tube pull clearance is
one unit length on either end with 60" (1.52 m) clearance
on the opposite end.
Absorption chillers are not suitable for outdoor installa tion.
The machine room must be enclosed, well lighted and
properly ventilated to keep its temperature no higher than
104°F (40°C) and no lower than 35°F (1.7°C).
WATER CIRCUITS
Flow Rate – For normal water chilling duty, chilled and
tower water flows are permitted at any velocity between
3.3 and 10 fps (1.0 and 3.05 m/s). YPC chillers are de-
signed for constant flow systems. Applications involving
chilled and condenser water flow rates which vary by
more than +/- 10% from design will require special con-
sideration. Contact your Johnson Controls representative.
Temperature Ranges – For normal chilling duty, leav-
ing chilled water temperatures may be selected between
41°F and 60°F (5.0°C and 15.55°C) for water temperature
ranges between 8°F and 20°F (4.4°C and 11.1°C).
Water Quality – The practical and economical applica-
tion of liquid chillers requires that the quality of the water
supply for the evaporator and the absorber/condenser be
analyzed by a water treatment specialist. Water quality
may affect the performance of any chiller through corro-
sion, depositions of heat-resistant scale, sedimen tation or
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organic growth. These will hurt chiller perform ance and
increase operating and maintenance costs. Normally,
performance may be maintained by corrective water treat-
ment and periodic cleaning of tubes. If water conditions
exist which cannot be corrected by proper water treatment,
it may be necessary to provide a larger allowance for foul-
ing, and/or specify special material of construction.
General Water Piping – All chilled water and tower wa-
ter piping should be designed and installed in accord ance
with accepted piping practice. Chilled water and tower
water pumps should be located to discharge through the
YPC unit to assure positive pressure and flow through
the unit. Piping should include offsets to provide flexibil-
ity and should be arranged to prevent drainage of water
from the cooler and condenser when the pumps are shut
down. Piping should be adequately supported and braced
independent of the chiller to avoid imposition of strain on
chiller components. Hangers must allow for alignment of
the pipe. Isolators in the piping and in the hangers are
highly desirable in achiev ing sound and vibration control.
Convenience Considerations – With a view to facilitat-
ing the performance of routine maintenance work, some
or all of the following steps may be taken by the pur chaser.
Evaporator, absorber and condenser water boxes are
equipped with plugged vent and drain connec tions. If
desired, vent and drain valves may be installed with or
without piping to an open drain. Pressure gauges with
stopcocks, and stop valves, may be installed in the inlets
and outlet of the tower and chilled water lines as close
as possible to the chiller. An overhead monorail or beam
may be used to facilitate servicing.
Connections – The standard YPC unit is designed for
150 PSIG (10.3 bar) design working pressure in both the
chilled and tower water circuits. The connections (water
noz zles) to these circuits are furnished with grooves for
ANSI/AWWA C-606 couplings (ANSI flanges are optional).
Piping should be arranged for ease of disassembly at
the unit for performance of such routine maintenance as
tube cleaning. A crossover pipe is shipped loose to route
the tower water from the absorber up into the condenser.
All water piping should be thoroughly cleaned of all dirt
and debris before final connections are made to the YPC
machine.
Pump On/Off Control – Contacts are provided in the
YORK MicroComputer Control Center to start/stop chilled
and tower water pumps. The contacts can be used to
supply 115V power to a pump motor starter relay, or as
dry contacts to signal a building automation system to
start/stop flow through the chiller. Johnson Controls rec-
ommends that these contacts be used for all installations
FORM 155.19-EG3 (1011)
JOHNSON CONTROLS