One worry that is commonly faced by HVAC systems is high suction pressure. But what reasons high suction pressure? You need to have actually a good understanding of your refrigeration bike to check out what is keep going in each process. If you do not have actually an expertise then you will certainly spend more time guessing what the trouble is rather of fixing the problem.

The refrigeration cycle should be examined. A basic understanding of your refrigeration device is learning around the 2 operating systems. The two systems space suction pressure and discharging pressure. There space both high and also low settings for each press line.

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For a high-pressure suction to occur you might have an poor compressor. An interpretation your refrigeration has a leaking discharge valve. This indicates that your compressor cannot carry out the necessary refrigerant to the evaporator to handle the cooling load. Without a essential 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 push is a difficulty that deserve to be conveniently determined and fixed. One means to identify if the problem is fixable is by analyzing your compressor. If her compressor piping and amperage appear fine, then you have to perform one more analysis.

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

If your temperature and pressure outlet of the evaporator or suction press keeps going increase it means you are having actually a problem with your EXV.

Some reasons you are having actually high suction pressure include:

System load too highExpansion valve capacity also highCapacity regulator too largeHot gas bypass/capacity regulator defectiveSet too highOne or more compressor key valves leaking

What causes Your Suction press to Rise?

When her compressor has both a low head pressure and a high suction pressure your refrigeration tools is tho running, yet the temperature is dangerously low. Her compressor is quiet cooling, however not cooling come its rated capacity.

Your tool temperature assets will damn quicker. The main reasons her compressor will have actually simultaneously low head pressure and also high suction pressure is due to:

Worn compressor piston ringsLeaky oil separator return line

Your compressor valves may come to be inefficient early out to bad sealing from dirt and also debris deposits. Friend may have actually experienced the slugging of refrigerant oil, moisture, and heat build-up or flooding problems. There may have actually been compressor overheating due to the fact that of undercharging your refrigerant or superheating your refrigerant. All room perfectly explainable factors for having compressor problems.

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

Symptoms that a Leaky Valve

You should closely monitor and also examine whether or no you have

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

If you notice greater than common discharge temperatures, this shows your discharge valve is no sealing properly and has been damaged. This directly reasons low head pressure. This causes the heating of the discharge gases come be repetitive over and also over again. This causes higher than typical discharge temperatures.

You may likewise be experiencing low head press from your valve. This is due to the fact that some of the discharge gases room being brief cycled native the compressor cylinder. This create a low refrigerant circulation to the condenser. This produces a decreased heat load on the condenser the lowers the head pressures and temperatures.

If you are experiencing a greater subcooling, this is since there is a decreased refrigerant flow through the condenser. Meaning, your whole system is flow at a reduced rate v the condenser. Most of your refrigerant is in your condenser and also receiver.

You may likewise have high suction pressure. This procedure occurs due to the fact that the upstroke suction follow me the compressor’s cylinder sneaks earlier into the suction line. ~ all, the suction valve is not seating properly. The results are greater suction pressure since the refrigerant vapor during the downstroke is effectively functioning, however the upstroke is mistakenly functioning.

You may additionally have a higher suction pressure as result of a leaky discharge valve. This allows the discharge gas come sneak up right into the compressor’s cylinder throughout the downstroke. Her suction pressure increases due to the fact that the suction valve is gift open during the part of the downstroke the the compressor. This creates the bike of high suction pressure, which damages your refrigerant.

What is a Worn Compressor Ring?

Worn compressor rings occur when the discharge gases leak v the compressor’s piston rings. This produces a lower head pressure during the compression punch in the system. The suction press is elevated because the discharge gases have leaked with the rings. The result is greater than normal suction pressure.

The results of having actually worn compressor rings develop lower head press with high suction pressure. The results of having worn rings within her compressor appear similar to having leaky valves.

Leaky Oil Separator Explained

Your oil separator controls your high and also low sides of her refrigeration system. This permits the oil to travel from the oil separator come the compressor’s crankcase. Her oil separator is on the high side of the system, while the compressor crankcase is on the short side.

High press occurs once the needle valve gets partially stuck open and also goes straight into the compressor’s crankcase. This reasons both high low-side pressures and low high-side pressures.

You should carefully monitor whether or not the oil return heat is above or listed below the ambient neighboring temperature. If the heat is warm then the discharge gas is most most likely sneaking to the partially open up needle valve in the oil separator.

Problems through Your electrical Expansion Valve

Electric expansion valves allow for assist to keep and permit efficient manage of the chiller during low load or head pressure conditions. The EXV can manage the circulation of refrigerant the enters the direct expansion evaporator. They perform this in response to signals sent to them by an digital controller. A tiny motor is supplied to open and close the valve port.

If her suction pressure keeps increasing within her refrigerator system you need to inspect on miscellaneous parts of your refrigerator that include:

The settings for superheatReplace your electrical expansion valveFind correct size

When friend are having trouble v your suction push you should inspect to watch if the setups for superheating space correct. If this is still no correcting the trouble you should examine your EXV to view if the is working properly. It might need replacing. Friend will need to find the right size for the ideal refrigerant.

Condenser difficulties Explained:

If her valve and compressor are all working effectively there are other possible reasons the suction push is high. One reason is her condenser might be dirty. There will certainly be a greater temperature if the amount of heat cannot be easily determined when using the cooling medium. This creates a higher temperature 보다 the architecture temperature in ~ the inlet the the evaporator.

The greater temperature in ~ the inlet will cause high outlet temperature and also pressure and also high suction pressure occurs. Another possibility is having dryer problems. A dryer is a holding vessel that receives the liquid refrigerant native the outlet that the condenser.

The condenser’s primary function is to make sure only liquid refrigerant will the growth valve. It additionally contains a substance the absorbs moisture to assist dry the end your refrigerator. If the dryer is clogged and full that moisture, then less liquid passes with it.

This creates much less liquid come reach your evaporator, producing a greater temperature, and pressure in ~ the outlet will be high. This entire process creates a high suction pressure. Friend should very closely examine what type of cool kind your condenser is. The types include

Air CooledWater Cooled

If the condenser is air-cooled type, then the fan should be sufficient sufficient to remove the warmth from the refrigerant. The temperature need to then revert come its straightforward setting. If your condenser is water-cooled climate the cooling water temperature and flow rate should be able to remove the warmth from the refrigerator. Her condenser is then in a subcooled state in ~ the main collection temperature.

Other factors for High Suction Pressure

After carefully assessing and considering every one of the previously mentioned possibilities because that high suction pressure there are still various other reasons for having high suction pressure. In every one of the previously disputed reasons, you probably assumed a high superheat, higher temperatures lead to greater pressure in ~ the suction line.

Another element to think about is the overcharging the the refrigerant. Overcharging leads to overfeeding the evaporator with refrigerant, which leader to higher suction pressure.

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Another opportunity is having actually oversized EXV causes an overfeed to the evaporate, which rises your suction pressure. Not all of the factors for high suction pressure is since of high superheat and greater temperatures.