Rev 07/04/2015
14
3.3.
PRESSURE SWITCH
There is a pressure regulating switch installed to prevent compressor failures or improper
operation due to high discharge pressure. Self contained models have a high pressure
switch only, while remote units have a double switch, like the one shown below. In the old
models both types of application had a double switch, triggering alarm “hp” either for a low
or high pressure event. In some recent remote application, the pressure switch is used for
pump down purpose also.
3.3.1 Pressure Switch Working Principles – Alarm Connection
The pressure switch has normally closed contacts that will open if the High or Low
pressure limits are exceeded. The switch is connected to the Main Board at terminals 48 &
50 in case of standard controller (48 is a shared connection with the door switch), and
terminals GND & D1 in Touch Screen version. When the pressure switch opens from
either a high or low pressure condition, the display will show the error code “hP” (or
message “HIGH PRESSURE” in Touch screen version).
PRESSURE
SWITCH
HIGH/LOW CUT
OUT PRESSURE
SCALE
DIFFERENTIAL
CAPILLARY
TUBES
SWITCH
CABLES
STANDARD
VERSION
Summary of Contents for GBC-15
Page 1: ...Service Manual Blast Chiller...
Page 2: ...Rev 07 04 2015 2...
Page 3: ...Blast chiller Service Manual 3 Rev 07 04 2015...
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Page 50: ...Rev 07 04 2015 10 20 10 0 10 20 30 40 kOhms C kOhmsVsTempChart NTC 10kOhms 25 C ZOOM...
Page 57: ...Blast chiller Service Manual 17 Rev 07 04 2015 L1 L2...
Page 91: ...Blast chiller Service Manual 51 Rev 07 04 2015 6 SCHEMATICS 6 1 SCHEME OF COMPONENTS...
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