When charging a system with a low pressure control and the control keeps shutting the compressor off, you should:
The pressure transducer in parallel compressor systems measures the pressure of the refrigerant in the system and provides feedback to the control system. This helps maintain the desired pressure levels in each compressor, ensuring balanced operation and efficiency.
funtion of the low pressure control is to pump down compressor in case of low pressure in the system
A refrigerator compressor is the center of the refrigeration cycle. It works as a pump to control the circulation of the refrigerant, and it adds pressure to the refrigerant, heating it up. The compressor also draws vapor away from the evaporator to maintain a lower pressure and lower temperature before sending it to the condenser.
Mechanical control system for an compressor?
Shock in a compressor refers to the sudden increase in pressure due to a rapid change in operating conditions, such as starting and stopping the compressor suddenly. This can cause mechanical damage and reduce the lifespan of the compressor. Proper control and gradual changes in operating conditions help prevent shock in a compressor.
If system was either opened or totally empty it will need to be evacuated prior to charging Is compressor running? Are control cables working properly?
Surge Limit is the Minimum Flow Point ( in the compressor characteristic curve ) below which the compressor operation become instable. If the flow-rate is reduced, the pressure developed by the compressor decreases. Then, the pressure in the discharge line becomes greater , and the gas flow back into the compressor. As soon as the pressure in the discharge line drops to below that developed by the compressor, the gas again flows in the discharge line. Then, the cycle repeats. The oscillating pressure and flow rate will cause audible vibrations and shocks, and could damage the compressor blades, seals, and other components. Therefore, the compressor requires an antisurge control system to limit the flow rate at a minimum point, safely away from the surge limit.
Most air compressors do not have a continuous load, as a result there is a need to control the amount of air entering the system. One way to allow for load swings is to let the air surge tank pressure float between two pressures. To do this you can either start and stop the compressor automatically to stay with in the required pressure range. Say pressure Pmin and Pmax. During normal requirement(load) of air, compressor will work at below Pmax.But when the requirement(load) decreases, delivery pressure start to increase. And when pressure equalise to Pmax,compressor start to unload(means pressure of the compressor start to decrease). During unloading air inlet valve is closed and delivery pressure decreases till it become equal to Pmin. Working of compressor in this phase is known as unloading. As soon as pressure become equal to Pmin compressor start to load again till it reaches Pmax. working of compressor in this phase is known as loading.
Besides fuses,there are relays that activate this compresorm most of them located under the hood; however, most of the compresors have a pressure control switch, if you have a small loss of refrigerant, eventually it is going to loose pressure an your compressor will not start to prevent compressor damage. Evacuate the system and refill with the correct amont of refrigerant.
Some possibilities: (1) The internal cabin temperature sensor may be bad. (2) The relay that controls the A/C compressor is bad. (3) The A/C refrigerant needs re-charging (if there is not enough in the system the compressor will not turn on, in order to prevent itself from burning out).
by checking the compressor
A centrifugal compressor is in surge when the flow rate through the compressor is reduced below the minimum stable flow rate, leading to a reversal in the direction of flow. This condition can cause the compressor to vibrate, make noise, and potentially damage the equipment. Surge can be detected by monitoring key parameters such as suction pressure, discharge pressure, and flow rate.