Schreiber Chillers 15MEDAC email - Manual (Page 27)

COMPRESSOR/EVAPORATOR SYSTEM
Refer to the illustration on the next page for detail below :
Each refrigeration system is mounted on a galvanized steel skid, and is completely self
contained. It contains the following:
High Pressure Switch
The high pressure switch is a manually resetting, totally encapsulated switch that is mounted on a
Schrader valve connection. If the switch requires replacement it can be unscrewed from the
piping system without loss of refrigerant. In the event of a high pressure switch failure, the
switch must be manually reset by pressing the red button. It will close when the system head
pressure is below the switch cut-in pressure. The controller must then be reset.
Low Pressure Switch
The low pressure switch is a automatically resetting, totally encapsulated switch that is mounted
on a Schrader valve connection. If the switch requires replacement it can be unscrewed from the
piping system without loss of refrigerant.
When the suction pressure drop below the cut out value, the compressor will shut off after a short
time delay. At compressor startup there is a starting time delay that ignores and open low
pressure switch to allow suction pressure to be built up. If the suction pressure does not build up
fast enough, the time delay can be increased.
Pressure Transducer
The pressure transducer reads the head pressure of the system and transmits this value to the
controller. The controller uses this value to determine the proper fan speed. It is installed on a
Schrader valve connection allowing it to be removed without a loss of refrigerant.
Liquid Line/ Suction Line Heat Exchanger
This heat exchanger sub-cools the liquid leaving the receiver and superheats the gas leaving the
evaporator. This prevents flashing in the liquid line and helps control liquid returning to the
compressor.
Filter Drier
A large liquid line filter drier is installed to protect the refrigeration system from contaminants.
The core is not replaceable, so the entire unit should be changed if the refrigeration system is
opened for service.
Sight Glass/ Moisture Indicator