Regarding this article, will inform you of the Ultimate Guide to Water Chiller Systems.

The content includes the following:

1. How to do when high-pressure alarms?
2. How to do when low-pressure alarms?
3. How to do when oil pressure differential alarm?
4. How to do low when compressor thermal protection?
5. Cooling capacity is poor, No reach the set temperature?
6. How to do when exhaust temperature alarm?
7. How to do if the evaporator frosting serious?
8. How to do when compressor oil back bad?
9. How to do when compressor suction temperature is too high?
10. How to determine the refrigerant charge?


Guide 1 – How to do when high-pressure alarm?

1. Reasons :

1) Cooling water (or air) flow is too small to take the heat from the compressor condensation.
2) Cooling Water (or air) temperature is too high to take the heat from the compressor condensation, also the heat transfer is not good.
3) There is air in the system, which makes the condensation pressure rise.
4) Excessive refrigerant charge, the liquid occupies the effective condensation area then make the condensation pressure increased.
5) The condenser disrepair. Heat transfer surface fouling is serious, it can also lead to condensation pressure rise.

There are plenty of other reasons, but consider from the bellow first:

1. There is much more refrigerant in the condenser.
2. Refrigeration Systems have other impurities that occupy the condenser heat transfer.
3. The condenser does not condense well









( dirty condenser )

2. How to process?

1) Check whether there is any problem with the high voltage control and whether there is an error alarm.

2) Touch the condenser, if the condenser is hot, then the heat transfer effect is not good. So need to check whether the problem with the cooling water (or condensation Fan).

3) Try releasing a little bit of the refrigerant.







(Cleaning water-cooled condenser)


Guide 2- How to do when low- pressure alarms?

1. Reasons:

There are many reasons for the low evaporation temperature.  Usually, it will be affected by the lack of refrigerant in the evaporator or the poor heat transfer of the evaporator

1) The expansion valve is less open.
2) The cooling system is short of refrigerant
3) The capillary or expansion valve is blocked
4) The filters are clogged.
5) Lack of internal air flow
6. Evaporator frosted seriously

1 ~ 4 points are mainly analyzed from the refrigerant less, 5 ~ 6 points main analysis evaporator heat transfer is not good.

2. How to process?

1) Check the low voltage control, make sure the voltage control has no problem and no false alarm.

2) Check the evaporator for dirt, block up the return air of the evaporator (whether the water-cooled evaporator has incrustation affected heat transfer).

3) Check the evaporator to see if the frost is serious, if so, check the evaporator fan (or frozen water) whether has the problem, exclude the small air or small water volume.

4) Check the expansion valve is dirty block and other faults, remove the expansion valve opening small cause of low evaporation pressure.

Guide 3 – how to do when oil pressure differential alarm?


(oil differential)

1. Reason :

A compressor is a complicated machine running at high speed. It is the basic requirement to keep the compressor running normally to ensure the lubrication of the crankshaft, bearing, connecting rod, piston and so on.

The main reasons are as follows:

1) The refrigeration oil insufficient causes the compressor crankcase oil level is insufficient, the oil pump can not suck the oil.
2) The oil dirty, cause oil pump filter plug.
3) The oil differential relay is out of order.
4) Failure of the oil pump.
5) There is a large amount of freon in the frozen oil, causing the oil pressure to fail to build up.
6) The return fluid —— The danger is in the dilution of the lubricant.

2. How to do?

1) Add enough refrigerant oil to the standard liquid level of the Mirror.
2) Replace the new cooling oil, cleaning the filter screen.
3) Replace the new oil differential relay.
4) Replace oil pumps.
5) Shutdown, through the compressor’s own electrolytic heat in the crankcase heating, plays up the oil fluorine separation or the next start-up needs to ensure that the refrigeration oil above normal temperature.
6) Diluted lubricating oil to the friction surface, low viscosity, can not form a thick enough to protect the oil film, over time will cause wear, adjust the over-liquid evaporator.

Guide 4 – How to do when compressor overheating protection?

1. Reasons:

1) The return air of the system is lack and the motor is not cooled enough.

2) The power supply voltage is abnormal, lack of phase, motor overload.

3) High motor temperature due to high condensation pressure, high exhaust gas temperature, the phenomenon of oil overheating such as coke.


Compressor heat protector

2. How to handle?

1) Adjust the cold expansion valve, increase the circulation of the system, so that the motor is fully cooled.

A1. Check if the pipeline is blocked (supply cut-off valve, dry filter, solenoid valve, the filter before of the expansion valve ) if there is a blockage, make sure solve it asap.

A2. Check the back air pipeline and the suction filter of the compressor for blockage and repair.

A3. Check if there is a shortage of refrigerants, In case of lack of refrigerant, supplement refrigerant.

2) Check whether the three-phase voltage of power supply is in the standard and whether the resistance between the phase sequence is balanced.

3) The condenser cooling area is not enough, scale, cooling air or water quantity is not enough, cooling water or air temperature is too high can lead to high condensation pressure.

C1. The exhaust temperature is greatly affected by the compression ratio. The higher the compression ratio, the higher the exhaust temperature. The suction pressure is determined by the evaporation pressure and suction pipe resistance.

Guide 5 – Cooling capacity is poor, how to do it can’t reach the preset temperature?

1. Reasons :

1) Expansion valve opens too large or too small, expansion valve opened too large compressor itself serious frost accumulation. Too much liquid, too small expansion valve open, too little liquid.

2) System blockage, such as filter blockage, expansion valve blockage, relevant valves are not open or open enough, solenoid valve failure.
3) Lack of refrigerant.
4) The paper pad of the upper part of the valve plate or the lower part of the cylinder of the compressor is broken or broken or the suction and discharge valve piece of the compressor is broken.

2. How to handle it?

1) Adjust the expansion valve, so that the compressor to achieve the best- operating conditions.
2) Find out the location and cause of the blockage and clean it out promptly.
3) According to the actual conditions of the compressor to supplement the appropriate amount of refrigerant.
4) Replace the new paper pad or exhaust valve plate.


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