17
Refrigeration System
!
Compressor:
The unit includes a
high efficiency scroll compressor
with and internal vibration isolator
that absorbs starting and stopping
energy. It also contains an internal
overload protection. External
vibration isolation is provided by
rubber mounting devices located
underneath the mounting base of
the compressor.
!
Water-to-Refrigerant Heat
Exchanger:
The water-to-
refrigerant heat exchanger is a
high quality stainless steel braze
plate heat exchanger. This
stainless material offers
exceptional corrosion resistance.
The heat exchanger has a working
pressure rating of 450 psig on both
the refrigerant and water sides. To
help ensure clean water for the
water-to-refrigerant heat
exchanger, Trane recommends a
sand filter/separator for open loop
systems.
!
Freezestat and Lock-out Relay:
A
freezestat is included to protect the
unit from unusually cold loop fluid
temperatures or no fluid flow
conditions. A 35 degree F
freezestat is necessary in open
loop applications and closed loop
applications without adequate
antifreeze. A 20 degree F
freezestat may be used with closed
loop applications with antifreeze
solution only. A lockout relay
circuit consisting of three safety
devices (low pressure, high
pressure, and Freezestat) will
trigger the lockout relay to shut off
the compressor, the loop pumps
and the desuperheater pump
(optional) when a safety is tripped.
A triggered lock-out relay is a key
indication that there is a problem
in the system and service may be
necessary. The safety that caused
the lockout relay to energize will
reset itself after approximately
five minutes. If the lockout relay is
manually reset by power
interruption prior to this five
minute period, the unit will be
unable to run. To manually reset
the lockout relay, the disconnect or
system switch at the thermostat
must be toggled.
!
Reversing Valve:
The reversing
valve is a pilot operated sliding
piston type with replaceable
encapsulated magnetic coil. The
reversing valve is energized when
the unit is in the cooling mode and
de-energizes in the heating mode.
!
Refrigerant Tubing:
All refrigerant
tubing is constructed of copper.
The low temperature refrigerant
lines are factory insulated with a 3/
8-inch thick elastomeric insulation
(UL 94V-5 rated), with a flame
spread rating of less than 25 and
smoke density rating of less than
50. It has been tested in
accordance with ASTM-85.
!
Refrigerant Metering:
The
refrigeration circuit is provided
with a bi-directional thermal
expansion valve to allow operation
with entering water temperatures
from 25 degrees F to 120 degrees
F.
!
Liquid Line Filter:
The unit
contains a bi-directional liquid line
filter drier to remove any
contaminants within the
refrigeration circuit.
!
Servicing Pressure Ports
: The
equipment is provided with both
high and low pressure schraeder
ports. The ports are located
outside the unit case for
convenient access.
Refrigeration System