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Condenser Water Regulating Valve (Water Cooled Units Only)
A condenser water regulating valve is provided as standard. This valve is located in the condenser water piping at the
outlet of the condenser. It regulates the flow of water through the condenser in order to maintain the high-pressure side of
the refrigeration circuit. This valve is set at the factory and should only be adjusted by a qualified refrigeration technician.
The valve only passes as much water as is required to maintain the refrigerant pressure, so less water will be required if the
water temperature is lower than the design 85°F (29°C). Refer to Table 2 for minimum condenser water flow requirements
for different supply water temperatures.
Note: The condenser water regulating valve may not completely shut-off water flow when the chiller is not operating. If flow must be completely
stopped for any reason, a shut-off valve (manufactured by others) must be used. Make sure the shut-off valve is reopened before restarting the chiller.
Condenser Remote Air-Cooled
(EQR Models Only) The remote air-cooled condenser has a copper tube and aluminum fin coil with fan(s). The refrigerant
passes through the copper tubes, while the air passes over the fins. The condenser supplied is equipped to vary the header
fan(s) speed and operate the remaining fans (if present) as needed to control the refrigerant discharge pressure under
varying ambient and chiller loading conditions. Please see the air-cooled remote condenser installation instructions for
proper mounting and connection of the condenser.
Evaporator
The evaporator is constructed of stainless steel plates and copper brazing. The refrigerant passes between every other set
of plates, while the coolant flows on the other side of the plates in the opposite direction.
Thermostatic Expansion Valve (TXV)
The TXV separates the high pressure/high temperature side of the refrigeration circuit (the condenser side) from the low
pressure/low temperature side of the refrigeration circuit (the evaporator side). The TXV maintains constant superheat at
the evaporator outlet, regardless of process load, by precisely metering the amount of refrigerant into the evaporator.
Superheat is the difference between the saturated evaporative temperature and the actual measured temperature at the
TXV sensor bulb. The superheat is factory set for 10°F to 12°F (5°C to 6°C) and should never exceed 15°F (8°C). Only a
trained refrigeration technician should adjust this valve.
Refrigerant Sight Glass
The refrigerant sight glass is located in the liquid line immediately ahead of the expansion valve. It allows the operator or
service technician to observe the flow of liquid refrigerant. Prolonged periods of foaming in the sight glass may indicate a
low refrigerant condition or a restriction in the liquid line.
Note: Occasional bubbling in the sight glass may occur at a time when load conditions are changing and the thermostatic expansion valve is adjusting
to the new conditions. This momentary occurrence is a result of normal chiller operation.
The sight glass can also be used to check if there is moisture in the refrigeration system. If there is moisture in the system,
the green dot in the center of the sight glass will turn yellow. If this occurs, the chiller should be serviced immediately.
Refrigerant Filter Drier
The filter drier is located in the liquid line between the condenser and the refrigerant sight glass. It is designed to remove
any moisture and/or foreign matter that may have gotten into the refrigerant stream. Moisture and foreign matter can
cause serious damage to the components of a refrigeration system. For this reason, it is important that the chiller be
equipped with a clean filter drier. Replace the filter drier if any of the following conditions occur.
1.
The refrigeration system is opened to the atmosphere for repairs or maintenance.
2.
Moisture is indicated in the sight glass (the green dot has changed to yellow).
3.
An excessive pressure drop develops across the filter drier. This is indicated by a significant temperature difference
between the filter inlet and outlet.
Hot Gas Bypass Valve
This valve is located in the refrigerant line that runs from the compressor discharge to the evaporator inlet. It is designed to
artificially load the chiller when the chiller is catering to a partial load from the process. This is accomplished by directing
some of the hot compressor discharge gas directly back into the evaporator instead of going through the condenser. The
