One worry that is typically faced by HVAC solution is high suction pressure. But what reasons high suction pressure? You require to have actually a great understanding of her refrigeration cycle to check out what is keep going in each process. If you perform not have actually an knowledge then you will certainly spend much more time guessing what the difficulty is rather of resolving the problem.

The refrigeration cycle have to be examined. A straightforward understanding of your refrigeration system is learning around the two operating systems. The two systems are suction pressure and also discharging pressure. There space both high and low settings for each press line.

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For a high-pressure suction to take place you could have an poor compressor. Meaning your refrigeration has a leaking discharge valve. This suggests that her compressor cannot administer the necessary refrigerant come the evaporator to take care of the cooling load. Without a required refrigerant, the produces a higher temperature and pressure in ~ the outlet that the evaporator, which reasons a high suction pressure.

Suction and Discharging Pressure troubles Explained


High suction press is a trouble that deserve to be easily determined and fixed. One means to recognize if the difficulty is fixable is by assessing your compressor. If your compressor piping and amperage show up fine, then you need to perform another analysis.

You deserve to perform an analysis by check the outlet that the evaporator, i m sorry is leave the refrigerant in ~ a high temperature. Your remote bulb must react and also move the electric expansion valve, or EXC, come the opened direction come allow more refrigerant to flow in the evaporator to manage the cooling load.

If your temperature and also pressure outlet that the evaporator or suction pressure keeps going up it means you are having actually a difficulty with your EXV.

Some factors you are having high suction press include:

System fill too highExpansion valve capacity as well highCapacity regulator too largeHot gas bypass/capacity regulator defectiveSet as well highOne or an ext compressor bowl valves leaking

What causes Your Suction press to Rise?

When your compressor has both a short head pressure and also a high suction push your refrigeration equipment is quiet running, yet the temperature is dangerously low. Your compressor is still cooling, yet not cooling come its rated capacity.

Your tool temperature assets will spoil quicker. The main reasons your compressor will have actually simultaneously low head pressure and also high suction push is early out to:

Worn compressor piston ringsLeaky oil separator return line

Your compressor valves may come to be inefficient early out to negative sealing indigenous dirt and also debris deposits. Friend may have experienced the slugging of refrigerant oil, moisture, and heat buildup or flooding problems. There may have actually been compressor overheating because of undercharging her refrigerant or superheating your refrigerant. All room perfectly explainable reasons for having actually compressor problems.

Compressor overheating is a serious and most frequent problem for refrigerants.

Symptoms of a Leaky Valve

You should carefully monitor and also examine even if it is or no you have

higher than common discharge temperatureslow condensing head pressures and also temperaturesnormal to high condenser subcoolingnormal come high superheatslow amp draw

If girlfriend notice greater than normal discharge temperatures, this shows your discharge valve is no sealing properly and also has been damaged. This directly causes low head pressure. This causes the heating of the discharge gases to be recurring over and over again. This causes greater than normal discharge temperatures.

You may likewise be experiencing low head push from your valve. This is due to the fact that some of the discharge gases room being brief cycled indigenous the compressor cylinder. This create a short refrigerant flow to the condenser. This produces a lessened heat pack on the condenser that lowers the head pressures and also temperatures.

If you are experiencing a greater subcooling, this is since there is a decreased refrigerant flow through the condenser. Meaning, your entire system is flowing at a diminished rate through the condenser. Many of your refrigerant is in your condenser and also receiver.

You may also have high suction pressure. This procedure occurs since the upstroke suction along the compressor’s cylinder sneaks ago into the suction line. After ~ all, the suction valve is not seating properly. The outcomes are greater suction pressure since the refrigerant vapor throughout the downstroke is correctly functioning, however the upstroke is erroneously functioning.

You may likewise have a greater suction pressure as result of a leaky discharge valve. This allows the discharge gas come sneak up into the compressor’s cylinder during the downstroke. Her suction push increases because the suction valve is gift open throughout the component of the downstroke of the compressor. This creates the cycle of high suction pressure, which loss your refrigerant.

What is a Worn Compressor Ring?

Worn compressor rings occur when the discharge gases leak with the compressor’s piston rings. This produce a lower head pressure during the compression punch in the system. The suction push is elevated since the discharge gases have actually leaked v the rings. The result is higher than common suction pressure.

The results of having worn compressor rings produce lower head push with high suction pressure. The results of having actually worn ring within her compressor appear comparable to having actually leaky valves.

Leaky Oil Separator Explained

Your oil separator controls your high and also low sides of her refrigeration system. This enables the oil to travel from the oil separator to the compressor’s crankcase. Her oil separator is ~ above the high side of the system, if the compressor crankcase is top top the short side.

High press occurs as soon as the needle valve gets partly stuck open and goes directly into the compressor’s crankcase. This causes both high low-side pressures and also low high-side pressures.

You should carefully monitor even if it is or not the oil return heat is over or below the ambient neighboring temperature. If the line is warm then the discharge gas is most most likely sneaking come the partially open needle valve in the oil separator.

Problems v Your electrical Expansion Valve

Electric growth valves enable for help to maintain and allow efficient control of the chiller during low load or head push conditions. The EXV can manage the circulation of refrigerant the enters the straight expansion evaporator. They do this in solution to signals sent out to lock by an digital controller. A little motor is offered to open and also close the valve port.

If your suction push keeps climbing within her refrigerator device you require to inspect on assorted parts of your refrigerator the include:

The setups for superheatReplace your electrical expansion valveFind correct size

When you are having actually trouble v your suction press you should inspect to view if the settings for superheating space correct. If this is still no correcting the trouble you should inspect your EXV to check out if the is working properly. It might need replacing. Friend will need to uncover the appropriate size for the right refrigerant.

Condenser problems Explained:

If her valve and also compressor are all working appropriately there space other possible reasons the suction pressure is high. One factor is your condenser might be dirty. There will certainly be a higher temperature if the lot of heat cannot be easily figured out when making use of the cooling medium. This creates a higher temperature 보다 the architecture temperature at the inlet the the evaporator.

The greater temperature in ~ the inlet will result in high outlet temperature and also pressure and high suction press occurs. Another possibility is having dryer problems. A dryer is a hold vessel that receives the fluid refrigerant from the outlet that the condenser.

The condenser’s primary duty is to do sure only liquid refrigerant get the expansion valve. It also contains a substance that absorbs moisture to aid dry out your refrigerator. If the dryer is clogged and also full of moisture, then much less liquid passes through it.

This creates much less liquid to reach her evaporator, creating a greater temperature, and pressure at the outlet will certainly be high. This entire process creates a high suction pressure. Girlfriend should closely examine what type of cool form your condenser is. The species include

Air CooledWater Cooled

If the condenser is air-cooled type, then the fan have to be sufficient enough to eliminate the warm from the refrigerant. The temperature have to then revert to its an easy setting. If your condenser is water-cooled then the cooling water temperature and also flow price should be able to remove the warm from the refrigerator. Your condenser is then in a subcooled state in ~ the main collection temperature.

Other factors for High Suction Pressure

After carefully evaluating and considering every one of the abovementioned possibilities for high suction press there space still various other reasons for having high suction pressure. In every one of the previously questioned reasons, you probably assumed a high superheat, greater temperatures command to higher pressure in ~ the suction line.

Another aspect to take into consideration is the overcharging the the refrigerant. Overcharging leads to overfeeding the evaporator v refrigerant, which leads to greater suction pressure.

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Another opportunity is having oversized EXV reasons an overfeed to the evaporate, which rises your suction pressure. Not every one of the reasons for high suction pressure is due to the fact that of high superheat and greater temperatures.