Commercial Compressors: Why We Need To Understand Undercharge and Overcharge

An undercharge or overcharge of refrigerant may have a number of unfavorable effects for commercial compressors. This is because these circumstances restrict the compressor from performing at its best level, eventually leading to a faulty system that could harm your company.

A detailed understanding of HVAC/R systems and their functions is necessary for troubleshooting undercharge and overcharge issues with commercial compressors. To find the precise reason of a system fault before it worsens into a more serious issue, it is important to be able to recognize the signs of an undercharged or overcharged system.

To help you understand what an undercharge and an overcharge of refrigerant signify and why either circumstance is problematic, we’ve compiled a few fundamental facts below.

Identifying Conditions of Undercharge and Overcharge

A refrigeration or HVAC system’s refrigerant is a crucial component. The refrigerant goes through two isothermal phase transitions as it cools: first, it transforms from liquid to vapor, absorbing and carrying heat out of the surroundings. The refrigerant condenses back into liquid after dissipating the heat into the ambient air.

As a result of this shift in condition, HVAC and refrigeration systems may keep indoor climate- and humidity-controlled rooms at pre-set levels. The refrigerant doesn’t run out despite often changing states. As a result, the system should use the same quantity of refrigerant throughout its entire lifespan.

System charge is the term used to describe the factory-specified amount of refrigerant needed by an HVAC or refrigeration system to operate at peak efficiency. When the recommended factory-set level of refrigerant is not met, a system is undercharged. A system is overcharged, on the other hand, when it contains too much refrigerant.

Many individuals incorrectly believe that decreased cooling capability is mostly due to a lack of refrigerant. Thus, when a non-professional tries to solve a presumed cooling problem by adding extra refrigerant without taking into account other elements that could adversely affect system performance, a system may become overheated.

The more frequent undercharging of refrigerant, which frequently happens as a result of systemic leakage. If you notice any leaks, you should get in touch with a specialist as once to identify and address the problem. If there are concealed refrigerant leaks, the issue could not become apparent until your system’s capacity starts to decline.

Refrigerant Undercharge and Overcharge Symptoms

The following are some warning indicators that a system may be undercharged:

• Loss of cooling capacity; the system can no longer maintain the requisite levels of humidity and temperature;
• However, ice and frost can also form on the evaporator coil as a result of other issues; improper operating refrigerant pressures, which may cause evaporator coils to freeze;
• Intermittent hissing and gurgling sound at the metering device’s outlet during the cooling cycle, which controls the refrigerant flow into the evaporator;
• The evaporator coil’s high superheat;
• Low discharge and suction pressures;
• A compressor that overheats and becomes dysfunctional (e.g., runs constantly or makes short low pressure cut-out cycles);

A circuit breaker that constantly tripping or a compressor that struggles to start. The refrigerant cools the electric motor in a properly charged system. Overheating of the motor could result from low refrigerant levels. This could prevent the compressor from turning on or result in an early circuit breaker trip. If the problem is not fixed, the motor will eventually burn out and stop working altogether.

The following are the most typical signs of an overcharged system:

• High head pressure and high suction pressure with low suction superheat, which are signs of increased pressure throughout the system;
• Increased flooding of the compressor with refrigerant while it is off-cycle, which could result in flooded starts;
• Liquid refrigerant entering the suction line; this risky condition, often known as “liquid slugging,” may cause compressor damage;
• In addition to generating excessive subcooling at the condenser output, a condenser that is inundated with liquid refrigerant may lower its capacity and may short cycle on high pressure cut-out;
• A compressor with a louder-than-normal sound.

Compressor efficiency decreases in both overcharge and undercharge circumstances, increasing operational expenses. It’s crucial to have your commercial HVAC/R equipment frequently maintained by a qualified expert who can accurately identify and resolve any system issues if you want it to function effectively.