A water pressure switch is an electromechanical device that monitors the water pressure in a system and automatically controls a pump based on pre-set pressure thresholds. When pressure drops below a certain point, it activates the pump; when pressure exceeds another point, it deactivates the pump.
Here's a breakdown of how it works:
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Sensing the Pressure: The switch is connected to the water line. Internally, a diaphragm or piston is exposed to the water pressure.
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Mechanical Linkage: This diaphragm or piston is connected to a spring-loaded mechanism. The spring's tension can be adjusted, which sets the desired pressure thresholds (cut-in and cut-out pressure).
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Cut-In Pressure (Low Pressure Trigger): When the water pressure drops below the "cut-in" pressure (the low-pressure setting), the spring force overcomes the water pressure acting on the diaphragm/piston. This movement causes a set of electrical contacts to close.
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Electrical Circuit Completion: Closing the electrical contacts completes the circuit, sending power to the water pump. The pump then starts to increase the water pressure in the system.
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Cut-Out Pressure (High Pressure Trigger): As the water pump operates, the water pressure rises. When the pressure reaches the "cut-out" pressure (the high-pressure setting), the water pressure now overcomes the spring force. This causes the diaphragm/piston to move in the opposite direction.
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Electrical Circuit Interruption: This movement separates the electrical contacts, breaking the circuit and cutting off power to the water pump. The pump stops operating.
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Cycling: This process repeats automatically. As water is used, the pressure drops, eventually reaching the cut-in pressure, and the pump restarts. This cycle maintains the water pressure within the desired range.
In Summary:
The water pressure switch acts like an automated on/off switch for your water pump, responding to pressure changes to maintain a consistent water supply. It's essentially a pressure-sensitive relay.
