Refrigeration Compressor Troubleshooting Guide: Common Issues and Solutions

Figure 1: Bitzer refrigeration screw compressor.

Refrigeration compressors are essential components of any refrigeration system. They are responsible for compressing refrigerant gas, which then travels through the system to cool and freeze various products, including food, medicine, and other perishable items.

The type of refrigeration compressor used in a system depends on several factors, such as the cooling capacity required, the size of the system, and the intended use of the system.

However, like any mechanical component, compressor issues can arise, causing problems in the system's performance. In this article, we will review some common refrigeration compressor issues and their solutions.

1. Refrigeration Compressor Troubleshooting

Refrigeration compressor issues can lead to higher energy consumption, product spoilage, and system downtime. Here are some common refrigeration compressor problems and their troubleshooting methods.

Figure 2: Copeland scroll refrigeration compressor diagram.

1.1 Compressor Not Starting

One of the most common problems with refrigeration compressors is that they fail to start. This can occur due to various reasons, including electrical problems, mechanical issues or a malfunctioning motor. Here are some of the troubleshooting methods that can be used to address this issue:

● Check the power supply: Make sure that the system is plugged in and that the outlet is working correctly. If there is a problem with the power supply, the compressor will not start.
● Check the circuit breaker: If the circuit breaker has tripped, reset it and see if the compressor starts. If it does not start, there may be an issue with the wiring.
● Check the wiring: Inspect the wiring for any damage or loose connections. Tighten any loose connections or replace any damaged wiring.
● Check the motor: If the motor is faulty, it will need to be replaced or repaired by a professional technician.

1.2 Compressor Short Cycling

Another common problem with refrigeration compressors is short cycling. This occurs when the compressor turns on and off too frequently, which can cause wear and tear on the compressor and reduce its lifespan. Here are some of the troubleshooting methods that can be used to address this issue:

● Check the thermostat: If the thermostat is not functioning correctly, it may be causing the system to turn on and off excessively. Replace the thermostat if necessary.
● Check the refrigerant level: If the refrigerant level is too low, it can cause the system to short cycle. Check the refrigerant level and recharge if necessary.
● Clean the condenser coils: Dirty condenser coils can cause the compressor to short cycle. Clean the coils regularly to prevent this issue.

Figure 3: Cold storage compressor unit.

1.3 Compressor Overheating

If the compressor overheats, it can cause the system to shut down or even cause damage to the compressor itself. Here are some of the troubleshooting methods that can be used to address this issue:

● Clean the condenser coils: Dirty or blocked condenser coils can cause the compressor to work harder than necessary, leading to overheating. Clean the coils regularly to prevent this issue.
● Check the refrigerant level: Low refrigerant levels can cause the compressor to overwork and overheat. Check the refrigerant level and recharge if necessary.
● Check the motor: If the motor is faulty, it may be causing the compressor to overheat. A professional technician may need to be called in to diagnose and repair the issue.

1.4 Compressor Making Unusual Noises

If the compressor is making unusual noises, it may be a sign of a more serious issue. Here are some of the troubleshooting methods that can be used to address this issue:

● Check for loose or damaged components: Loose or damaged components within the compressor can cause it to make unusual noises. A professional technician may need to be called in to diagnose and repair the issue.
● Replace dirty or damaged bearings: Dirty or damaged bearings can cause the compressor to make unusual noises. The bearings may need to be lubricated or replaced.
● Check for refrigerant issues: If there is a refrigerant leak or other refrigerant issues, it can cause the compressor to make unusual noises. Check the refrigerant levels and repair any leaks if necessary.

Figure 4: Air-cooled condenser.

1.5 Compressor Not Cooling

If the compressor is running, but the system is not cooling, there may be an issue with the refrigerant flow. Here are some of the troubleshooting methods that can be used to address this issue:

● Check the refrigerant level: Low refrigerant levels can cause the system to not cool properly. Check the refrigerant level and recharge if necessary.
● Repair any refrigerant leaks: Refrigerant leaks can cause the system to not cool properly. Repair any leaks and recharge the system if necessary.
● Clean the evaporator coils: Dirty evaporator coils can cause the system to not cool properly. Clean the coils regularly to prevent this issue.

2. Refrigeration Compressor Repair

If a refrigeration compressor issue is repairable, it may be more cost-effective to repair it rather than replace it. The cost of refrigeration compressor repair varies depending on the type of compressor, the issue, and the labor costs. On average, the cost of a refrigeration compressor repair ranges between $200 and $1,000.

3. Refrigeration Compressor Replacement

If a refrigeration compressor is irreparable or has reached the end of its lifespan, it may need to be replaced. The cost of a refrigeration compressor replacement varies depending on the type of compressor, capacity, and installation costs.
On average, the cost of a new refrigeration compressor ranges from $500 to $2,000 for residential systems and up to $10,000 for commercial and industrial systems.

Figure 5: BITZER refrigeration compressor unit.

4. Conclusion

Many refrigeration compressor issues can be addressed through regular maintenance and troubleshooting. By following the troubleshooting steps outlined in this article, you can diagnose and potentially repair many compressor issues.

However, if the issue is more serious or requires professional expertise, it's important to call in a professional technician to diagnose and repair the issue properly.

5. FAQs

5.1 How Do I Know If My Refrigerator Compressor is Bad?

Here are some signs that your refrigerator compressor may be bad:

● Refrigerator not cooling properly.
● Unusual noises.
● Compressor hot to touch.
● Refrigerator cycling on and off frequently (Compressor short cycling).

If you notice any of these signs, it's important to call in a professional technician to diagnose and repair the issue properly.

5.2 What are the 3 Major Common Electrical Failures of Compressors?

The following are three major common electrical failures of compressors:

● Start Relay Failure
● Capacitor Failure
● Overload Protector Failure

These electrical failures can lead to significant issues with the refrigeration system if not addressed promptly. It's important to call in a professional technician to diagnose and repair any electrical issues with the compressor to prevent further damage to the system.

Figure 6: Capacitor junction box.

5.3 What is the Most Common Cause of Refrigerator Compressor Failure?

The most common cause of refrigerator compressor failure is overheating. Overheating can be caused by several factors, including: dirty condenser coils, low refrigerant levels, electrical issues, blocked or restricted airflow, age and wear, etc

Regular maintenance, such as cleaning the condenser coils, checking refrigerant levels, and inspecting electrical components, can help prevent overheating and extend the lifespan of the compressor.

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