SRC Service Manual
Revision 02
Aug 2007
3.1.5 Dew Point Temperature Sensor
All models have a Dew Point Temperature Sensor that measures the temperature of the air leaving
the Air-to-Coolant Heat Exchanger. At this point in the dryer, the temperature of the air equals the dew
point.
On the SRC-150 to 200 this controls the color Dew Point Indicator on the top of the dryer. On the
SRC-250 to 1000, this is the dew point temperature which is shown on the digital display during
normal operation.
3.1.6 Level Sensor
The SRC-400 through 1000 have a Level Sensor in the Condensate Chamber. This sensor sends a
signal to the microprocessor when the level of condensate reaches it, which then opens the
Condensate Drain Valve. Details of Condensate Drain Operation are covered in Section 9.
3.2 The Coolant Circuit
The Coolant Circuit consists of the Air-to-Coolant Heat Exchanger (described in 3.1.2 above) as well
as the Coolant-to-Refrigerant Heat Exchanger (which is mounted inside the Coolant Tank) and the
Coolant Re-circulation Pump.
The Coolant Circuit is pre-filled and pressurized* with a 58%Water / 42% Glycol coolant mixture with a
freezing point of approximately -13
o
F (-25
o
C), which is continuously circulated by the Coolant Pump.
A Coolant Pressure Relief Valve protects the system from over-pressure*, and a Coolant Expansion
Tank allows expansion and contraction of the coolant with changes in temperature.
* The maximum allowable working pressure of the Coolant Circuit is 87 psig. Maximum allowable working
pressures may vary with location depending on local pressure vessel design regulations.
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