Specifications

17JOHNSON CONTROLS
FORM 160.80-EG1 (511)
• safety shutdown contacts
• cycling shutdown contacts
• run contacts
HEAT PUMP CONTROL LOGIC
General: The Optiview control panel will be supplied with
three available operating modes, chilled water mode, heat
pump mode, and auto mode.
CHILLED WATER MODE
The compressor will load and unload to maintain the
LEWT setpoint as in a WATER CHILLER. The LCWT will
oat uncontrolled and be determined by the compressor
loading required to satisfy the LEWT setpoint.
HEAT PUMP MODE
The compressor will load and unload to maintain the
LCWT setpoint as in a HEAT PUMP. The LEWT will oat
uncontrolled and be determined by the compressor load-
ing required to satisfy the LCWT setpoint.
AUTO MODE
The automatic mode will optimize the operation of the
YS chiller/heat pump as the primary cooling source in
the winter and the primary heating source in the sum-
mer. This automatic mode will eliminate the need for the
chiller plant control system to switch between cooling
and heating control. The user will establish setpoints for
leaving evaporator water temperature (LEWT) and leav-
ing condenser water temperature (LCWT). At start-up,
the control panel will load the machine until one of the
setpoints (LEWT or LCWT) is reached and control to that
parameter, as described below.
If the LEWT setpoint is satised rst (indicating that the
heat pump chiller can produce all of the cooling required
by the system), the unit will load and unload to maintain
the LEWT as in a WATER CHILLER. The LCWT will oat
uncontrolled and be determined by the compressor load-
ing required to satisfy the LEWT setpoint.
If the LCWT setpoint is satised rst, (indicating that the
heat pump chiller can produce all of the heat required
by the system), the unit will load and unload to maintain
the LCWT, as in a HEAT PUMP. The LEWT will oat un-
controlled and be determined by the compressor loading
required to satisfy the LCWT setpoint.
In either scenarioo, there is no need for the user to select
an operating mode; only to determine the LEWT and
LCWT setpoint temperatures desired. At any time, these
setpoints can be changed either manually in the chiller
control panel, via a software input (LON, BACNET, etc.)
or hardwired input (4-20 mA/0-10V) signal.
CODES AND STANDARDS
• ASME Boiler and Pressure Vessel Code – Section
Vlll Division 1.
• AHRI Standard 550/590
• c/U.L. – Underwriters Laboratory
• ASHRAE 15 – Safety Code for Mechanical Refrigera-
tion
• ASHRAE Guideline 3 – Reducing Emission of Halo-
genated Refrigerants in Refrigeration and Air-Condi-
tioning Equipment and Systems
• NEC – National Electrical Code
• OSHA – Occupational Safety and Health Act
ISOLATION MOUNTING
The unit is provided with four vibration isolation mounts
consisting of 1” (25.4 mm) thick neoprene isolation pads
for eld mounting under the steel mounting pads located
on the tube sheets.
REFRIGERANT CONTAINMENT
The standard unit has been designed as a complete and
compact factory packaged chiller. As such, it has mini-
mum joints from which refrigerant can leak. The entire
assembly has been thoroughly leak tested at the factory
prior to shipment. The YORK chiller includes service
valves conveniently located to facilitate transfer of refrig-
erant to a remote refrigerant storage/recycling system.
Optional condenser isolation valves permit storage of the
charge in the condenser.
PAINT
Exterior surfaces are protected with one coat of Carib-
bean blue, durable alkyd-modied, vinyl enamel, ma-
chinery paint.
SHIPMENT
Protective covering is furnished on the motor, Control
Center and unit-mounted controls. Water nozzles are
capped with tted plastic enclosures.