LP & HP Switch

#HPcutout #LPcutout #safety #HVAC The LP and HP switch, also known as the HP and LP cutout, plays a vital role in HVAC compressor safety. The safety system for refrigeration compressor includes alarm, cut-offs, and trips which safeguard the machinery and its parts from getting damaged. As the name suggests the Low Pressure and High-pressure switch or the LP and HP switch safeguard the compressor from variable pressures and help it run safely in its rated pressure range. **DOWNLOAD REFRIGERATION EBOOKS FOR MARITIME PROFESSIONALS -- https://learn.marineinsight.com/eBook... Low Pressure cutoff switch or LP cut off: The LP cut out in refrigeation is a compressor safety which cut off the compressor in the event of pressure drop in the suction line. The pressure of the suction line is continuously sensed by the control unit and when it goes below the set value, which means the room is properly cooled, the LP cut out will auto trip the compressor. When the pressure rises, indicating there is a flow of refrigerant in the line due to an increase in room temperature, the LP switch will start the compressor. High pressure cutout switch or HP cutoff switch: As the name suggests, the hvac high pressure cut out activates and trips the compressor when the discharge side pressure increases above the limit value. The HP cut out is not auto-reset and has to be done manually. The reason behind it is to manually attend the fault which is leading to rising in pressure, else this situation can lead to overloading of compressor parts and may damage the same Oil differential cut out: This safety is again for the compressor as it is the only machinery in the circuit having rotational parts which require continuous lubrication. In the event of low supply or no supply of lube oil to the bearing, the differential pressure will increase and activates a trip signal to safeguard the bearing and crankshaft. Relief valves: Relief valves are fitted in the discharge side of the compressor and will lift and safeguard the compressor in the event of overpressure. One relief valve is also fitted in the condenser refrigerant line to avoid damage to the condenser if there is high pressure in the discharge line. Solenoid valves: Master solenoid valve is fitted in the common or mainline after the condenser discharge. It closes when the compressor stops or trips to avoid overflow of refrigerant into the evaporator. All holds or rooms are fitted with an individual solenoid valve which controls the flow of refrigerant to that room. ___ Stay connected with us! ► Subscribe to Marine Insight: http://bit.ly/2GUF1eM ► Like us on Facebook:   / marineinsight   ► Follow us on Twitter:   / marineinsight   ► Follow us on Instagram:   / marine_insight