High Pressure Cutout Switch
A high pressure cutout switch is located on the compressor discharge service manifold of the compressor. If the discharge pressure becomes too high, the switch opens the ground circuit to the compressor contactor coil.
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Compressor stops immediately. Evaporator and condenser fans continue normal operation.
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Controller determines that a high pressure cutout switch or compressor motor internal overload protector is open when the unit current draw during compressor operation is normal and then decreases by 7 amps for more than three seconds.
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After one minute, controller VGA display shows a High Pressure Cutout message:
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“HIGH PRESSURE CUTOUT CHECK CONDENSER PROBE”: Water pressure switch is open and the condenser temperature is low.
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“HIGH PRESSURE CUTOUT CHECK CONDENSER FAN”: Water pressure switch is open and the condenser temperature is high.
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“HIGH PRESSURE CUTOUT CHECK WATER COOLING”: Water pressure switch is closed.
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The controller continues to call for cooling so the compressor will restart when the overload condition is corrected (switch resets) if power is available.
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If the switch remains open for five minutes, the controller also turns on the Alarm indicator and records Alarm 37 (Total Power Consumption Too Low).
The high pressure cutout switch opens at 3243 ± 7 kPa, 32.43 ± 0.48 bar, 470 ± 7 psig, and closes at 2586kPa, 25.9 bar, 375 psig. To test the switch, rework a gauge manifold in accordance with High Pressure Cutout Manifold.