F 250 4WD Super Duty V8-7.3L DSL Turbo VIN F (2001)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C Pressure Switch
A/C Cycling Switch
A/C Cycling Switch
The A/C cycling switch is mounted on a Schrader valve-type fitting on the side of the suction accumulator/drier.
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A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.
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This allows the suction pressure inside the suction accumulator/drier to control the operation of the A/C cycling switch.
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The electrical switch contacts open when the suction pressure drops, the contacts close when the suction pressure rises.
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When the A/C cycling switch contacts close, the A/C clutch field coil is energized.
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When the A/C cycling switch contacts open, the A/C clutch field coil is dc-energized and compressor operation stops.
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The A/C cycling switch will control the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly
above freezing.
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This prevents icing of the A/C evaporator core and blockage of air flow.
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It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.
Air Conditioning High Pressure Switch
Typical Air Conditioning Pressure Sensor
The A/C pressure cut-off switch is used to interrupt the A/C compressor operation in the event of high system discharge pressures.
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The A/C pressure cut-off switch is mounted on a Schrader valve-type fitting on the high pressure side of the A/C manifold and tube.
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A valve depressor, located inside the threaded end of the A/C pressure cut-off switch, presses on the Schrader valve stem.
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This allows the A/C pressure cut-off switch to monitor the compressor discharge pressure.
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When the compressor discharge pressure rises, the switch contacts open, disengaging the A/C compressor.When the pressure drops, the contacts
close to allow operation of the A/C compressor.
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It is not necessary to discharge the refrigerant system to remove the A/C pressure cut-off switch.
