York YMC2 - Page 14

JOHNSON CONTROLS
FORM 160.84-EG1 (617)
14
into the compressor. A 1-1/2" (38 mm) liquid level sight glass is conveniently located on
the side of the shell to aid in determining proper refrigerant charge. The evaporator shell
contains a dual refrigerant relief valve arrangement or a single-relief valve arrangement, if
the chiller is supplied with the optional refrigerant isolation valves. A 1" (25.4 mm) refriger-
ant charging valve is provided for service access.
Condenser
The condenser is a shell and tube type, with a discharge gas baffle to prevent direct high
velocity impingement on the tubes. The baffle is also used to distribute the refrigerant
gas flow properly for the most efficient heat transfer. An integral sub-cooler is located at
the bottom of the condenser shell providing highly effective liquid refrigerant subcooling
to provide the highest cycle efficiency. A 1-1/2" (38 mm) liquid level sight glass is conve-
niently located on the side of the shell to aid in determining proper refrigerant charge. The
condenser contains dual refrigerant relief valves.
Water Boxes
The removable water boxes are fabricated of steel. Integral steel water baffles are located
and welded within the water box to provide the required pass arrangements. Stub-out
water nozzle connections welded to the water boxes are suitable for ANSI/AWWA C-606
couplings, welding or flanged, and are capped for protection during shipment. Plugged
3/4" (19 mm) drain and vent connections are provided in each water box.
REFRIGERANT ISOLATION VALVES
Factory-installed isolation valves in the compressor discharge line and refrigerant liquid
line allow isolation and storage of the refrigerant charge in the chiller condenser.
WATER FLOW SWITCHES
Thermal type water flow switches are factory mounted in the chilled and condenser water
nozzles, and are factory wired to the OptiView control panel. These solid state flow sen-
sors have a small internal heating element. They use the cooling effect of the flowing fluid
to sense when an adequate flow rate has been established. The sealed sensor probe is
316 stainless steel, which is suited to very high working pressures.
REFRIGERANT FLOW CONTROL
Refrigerant flow to the evaporator is controlled by the YORK variable orifice control sys-
tem. Liquid refrigerant level is continuously monitored to provide optimum subcooler,
condenser and evaporator performance. The variable orifice electronically adjusts to all
Real-World operating conditions, providing the most efficient and reliable operation of
refrigerant flow control.
OPTIVIEW CONTROL CENTER
The chiller is controlled by a stand-alone, microprocessor-based control center. The con-
trol center provides control of chiller operation and monitoring of chiller sensors, actua-
tors, relays and switches. See OptiView Control Center on page 17 for additional infor-
mation.
Equipment Overview (Cont'd)