Technical data

2.2 General Specification
YCWM/YCRM models are completely assembled
with all interconnecting refrigerant piping and
wiring ready for field installation. After assembly a
full run test is performed, with water flowing
through the evaporators, to verify that each
refrigerant circuit operates correctly.
YCWM units are pressure tested, evacuated and
fully charged with refrigerant and include an initial
oil charge.
YCRM units are pressure tested, evacuated and
include a nitrogen holding charge and initial oil
charge.
The unit base and frame is of heavy gauge
galvanised steel fastened with stainless steel
screws and bolts. All panels are easily removed for
access to components. Galvanised steel parts are
painted with baked-on enamel coloured blue.
2.3 Compressors
The hermetic compressors have internal motor
protection and an internal overflow valve from
discharge to suction. Starting is direct on line. The
compressors are mounted on rubber anti-vibration
pads and housed in a separate acoustically lined
enclosure.
Compressor lubrication is force-fed by a reversible
oil pump to all crankshaft and bearing surfaces
through a fine mesh stainless steel oil strainer.
The compressor motors are refrigerant gas cooled,
with integral thermistor protection against
overloads. The overload protection is
automatically reset after approximately 8 seconds.
The motor terminal boxes are to IP-54 weather
protection.
The compressors are switched On and Off by the
unit microprocessor to provide capacity control,
2.4 Refrigerant Circuits
Two complete refrigerant circuits are supplied on
each unit. All piping is ACR copper, with brazed
joints. Refrigerant circuits include: a service valve
for refrigerant charging, suction discharge and
liquid line isolating valves, a sight glass with
moisture indicator and thermostatic expansion
valve. High and low pressure switches and a
filter/drier are also included.
2.5 Evaporators and Condensers
(Models 60 to 150)
Each of the two evaporators and condensers is a
stainless steel plate type heat exchanger thermally
insulated with flexible closed cell material. Design
working pressure is 10 bar g on the water side and
30 bar g on the refrigerant side. An electric heater
mat and differential pressure switch is provided.
Each exchanger is provided with flow and return
water connections. Water connection is via 1 inch
gas threaded connections on models 60 and 75
and 1½ inch gas threaded connections on models
90 to 150.
2.6 Evaporator (Models 170 to 280)
The single dual-circuit steel shell and copper tube
evaporator is a direct-expansion type. It has
refrigerant in the tubes, which are formed in a hair-
pin configuration, and chilled liquid flowing through
the baffled shell. The evaporator is covered with
flexible, closed-cell, foam insulation.
Water connection to the evaporator is via victualic
type connections. The evaporator has a heating
element controlled by a thermostat. Water vent and
drain connections are included on the evaporator.
The evaporator design working pressure on the
water side is 10 barg and 30 barg on the refrigerant
side.
2.7 Condensers (Models 170 to 280)
The condensers are shell and tube type with a built-
in sub-cooler and removeable water heads. The
design working pressure on the water side is
10 barg and 30 barg on the refrigerant side.
2-2 035B40022-000