One issue that is generally faced through HVAC solution is high suction pressure. But what causes high suction pressure? You need to have a good understanding of her refrigeration bicycle to view what is keep going in each process. If you carry out not have actually an expertise then you will certainly spend an ext time guessing what the difficulty is instead of solving the problem.

The refrigeration cycle must be examined. A an easy understanding of your refrigeration system is learning around the 2 operating systems. The two systems are suction pressure and also discharging pressure. There space both high and also low setups for each pressure line.

You are watching: High head pressure normal suction pressure

For a high-pressure suction to occur you can have an inadequate compressor. An interpretation your refrigeration has a leaking discharge valve. This suggests that your compressor cannot administer the needed refrigerant to the evaporator to manage the cooling load. There is no a required refrigerant, that produces a greater temperature and pressure in ~ the outlet of the evaporator, which causes a high suction pressure.

Suction and also Discharging Pressure problems Explained


High suction press is a problem that can be easily determined and fixed. One method to identify if the problem is fixable is by analyzing your compressor. If your compressor piping and also amperage appear fine, climate you have to perform one more analysis.

You deserve to perform an analysis by checking the outlet that the evaporator, i beg your pardon is leaving the refrigerant at a high temperature. Your remote bulb have to react and move the electrical expansion valve, or EXC, come the opening direction come allow much more refrigerant to circulation in the evaporator to take care of the cooling load.

If your temperature and pressure outlet the the evaporator or suction pressure keeps going increase it way you are having actually a difficulty with her EXV.

Some reasons you are having actually high suction pressure include:

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

What causes Your Suction pressure to Rise?

When your compressor has actually both a short head pressure and a high suction pressure your refrigeration devices is quiet running, yet the temperature is dangerously low. Her compressor is quiet cooling, yet not cooling to its rated capacity.

Your tool temperature commodities will damn it quicker. The main reasons your compressor will have actually simultaneously short head pressure and also high suction press is due to:

Worn compressor piston ringsLeaky oil separator return line

Your compressor valves may come to be inefficient early out to bad sealing indigenous dirt and also debris deposits. Girlfriend may have experienced the slugging that refrigerant oil, moisture, and heat accumulation or flooding problems. Over there may have actually been compressor overheating since of undercharging your refrigerant or superheating her refrigerant. All room perfectly explainable factors for having compressor problems.

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

Symptoms the a Leaky Valve

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

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

If friend notice greater than common discharge temperatures, this suggests your discharge valve is no sealing properly and has to be damaged. This directly causes low head pressure. This reasons the heating of the discharge gases to be repeated over and also over again. This causes greater than common discharge temperatures.

You may additionally be suffering low head push from your valve. This is because some that the discharge gases room being quick cycled from the compressor cylinder. This create a short refrigerant circulation to the condenser. This produces a lessened heat pack on the condenser the lowers the head pressures and also temperatures.

If you room experiencing a higher subcooling, this is since there is a reduced refrigerant flow through the condenser. Meaning, your whole system is flowing at a lessened rate through the condenser. Many of your refrigerant is in your condenser and receiver.

You may likewise have high suction pressure. This process occurs due to the fact that the upstroke suction along the compressor’s cylinder sneaks back into the suction line. ~ all, the suction valve is no seating properly. The outcomes are greater suction pressure due to the fact that the refrigerant vapor during the downstroke is correctly functioning, yet the upstroke is erroneously functioning.

You may additionally have a higher suction pressure because of a leaky discharge valve. This permits the discharge gas come sneak up right into the compressor’s cylinder throughout the downstroke. Her suction pressure increases because the suction valve is gift open during the component of the downstroke that the compressor. This creates the bike of high suction pressure, which loss your refrigerant.

What is a Worn Compressor Ring?

Worn compressor rings happen when the discharge gases leak v the compressor’s piston rings. This produces a reduced head pressure throughout the compression punch in the system. The suction press is elevated due to the fact that the discharge gases have leaked through the rings. The an outcome is greater than common suction pressure.

The outcomes of having worn compressor rings develop lower head press with high suction pressure. The outcomes of having worn rings within your compressor appear comparable to having leaky valves.

Leaky Oil Separator Explained

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

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

You should carefully monitor even if it is or no the oil return line is over or listed below the ambient neighboring temperature. If the line is warm then the discharge gas is most likely sneaking to the partially open needle valve in the oil separator.

Problems through Your electric Expansion Valve

Electric expansion valves enable for assist to keep and enable efficient manage of the chiller throughout low fill or head pressure conditions. The EXV can regulate the flow of refrigerant that enters the straight expansion evaporator. They carry out this in an answer to signals sent out to lock by an digital controller. A small motor is supplied to open and also close the valve port.

If your suction push keeps increasing within her refrigerator system you need to examine on various parts of her refrigerator the include:

The settings for superheatReplace your electric expansion valveFind exactly size

When girlfriend are having trouble through your suction pressure you should inspect to watch if the setups for superheating space correct. If this is still no correcting the difficulty you should examine your EXV to view if it is working properly. It might need replacing. Friend will need to discover the appropriate size because that the appropriate refrigerant.

Condenser difficulties Explained:

If her valve and compressor are all working properly there are other feasible reasons the suction push is high. One factor is her condenser might be dirty. There will certainly be a higher temperature if the quantity of warm cannot it is in easily figured out when making use of the cooling medium. This creates a higher temperature 보다 the style temperature in ~ the inlet the the evaporator.

The higher temperature at the inlet will result in high outlet temperature and pressure and also high suction press occurs. One more possibility is having dryer problems. A dryer is a holding vessel the receives the liquid refrigerant native the outlet of the condenser.

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

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

Air CooledWater Cooled

If the condenser is air-cooled type, then the fan should be sufficient enough to eliminate the warmth from the refrigerant. The temperature need to then revert come its simple setting. If your condenser is water-cooled then the cooling water temperature and also flow rate should have the ability to remove the heat from the refrigerator. Her condenser is climate in a subcooled state at the main collection temperature.

Other factors for High Suction Pressure

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

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

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