Compressor Overload Protector Testing! How it Works!

Summary

In this informative video, Creamy Watcher from Easy Service Tech explains the function of a compressor overload protector, crucial for maintaining safety in high-amperage scenarios. The video details two types of protectors, their installation on reciprocating and rotary compressors, and demonstrates how they prevent electrical windings from burning out by opening the circuit during excessive amperage. Viewers also learn how to test these protectors using a multimeter and understand the importance of resistance readings in assessing their condition.

Takeaways

• 🔌 The video discusses the function of a compressor overload protector, which is to prevent electrical windings from burning out due to high amperage during startup.
• 🛠️ The video is sponsored by Dan Foss, offering free training programs accessible through a link in the description.
• 🔧 There are two main types of external compressor overload protectors: one typically found on fractional horsepower reciprocating compressors and another on rotary compressors.
• 🔍 The protectors can be identified by their flanges or round shape and may be open or have a plastic cap.
• 🛡️ The protector works by using a PTC thermistor that contains an electric resistance coil inside, which heats up during high amperage, causing a thermodisc to pop and open the electrical circuit.
• 🌡️ The script includes a demonstration of how the protector operates, showing the resistance across terminals and the effect of applying power only to the run winding.
• 📈 The video shows a test where the amperage and temperature are monitored, illustrating the point at which the protector activates.
• 🔍 When the protector is functioning correctly, it should not read zero ohms of resistance across the terminals due to the presence of the electric resistance heater.
• 🔥 A demonstration is provided to show how the protector gets hot and eventually opens the circuit, protecting the compressor.
• 🔄 The round type of protector operates similarly but uses a bi-metal disc that clicks open due to heat, breaking the circuit, and closes again when cooled.
• 🔗 The video script also includes links to a multimeter and a refrigerant charging book for those interested in HVAC tools and resources.

Q & A

What is the main purpose of a compressor overload protector?

The main purpose of a compressor overload protector is to prevent the compressor from burning out by opening the electrical circuit when high amperage is drawn during startup or operation.

What does the video discuss as the cause of a compressor not being able to start?

The video discusses that if a compressor is not able to start, it might be due to high amperage draw, which causes the compressor protector to open the electrical circuit to safeguard the compressor's electrical windings.

How is the video sponsored, and what is offered by the sponsor?

The video is sponsored by Dan Foss, who offers free training programs accessible through a link in the description section below.

What are the two main types of external compressor overload protectors mentioned in the video?

The two main types of external compressor overload protectors mentioned are the flanged type typically found on fractional horsepower reciprocating compressors and the round type usually found on rotary compressors.

Can you explain how the flanged type of compressor protector is mounted?

The flanged type of compressor protector is mounted by first placing it on the common terminal, ensuring the correct orientation, and then attaching the current starting relay or the PTC thermistor.

What is a PTC thermistor, and what role does it play in the compressor protector?

A PTC thermistor is a component inside the compressor protector that contains a small electric resistance coil. When high amperage flows through the coil, it heats up, causing a thermal disc to pop and open the electrical circuit to prevent damage.

How does the round type of compressor protector function?

The round type of compressor protector functions by having a bi-metal disc that heats up and clicks open the electrical circuit when too much amperage is drawn. Once cooled down, it closes the circuit, allowing normal operation.

What is the significance of the resistance value read across the terminals of a compressor protector?

The resistance value read across the terminals of a compressor protector indicates whether it is functioning correctly. A reading of 0 ohms indicates an open circuit, while a non-zero value suggests the presence of the internal electric resistance heater.

How can you test if a compressor protector is working properly?

You can test a compressor protector by applying power to the run winding, measuring the amperage with a multimeter, and observing if the protector opens the circuit at high amperage, as indicated by an increase in temperature and an open circuit reading.

What is the importance of checking the resistance value of a cool compressor protector?

Checking the resistance value of a cool compressor protector is important because if it reads 0 ohms, it indicates that the protector is not functioning correctly and needs to be replaced.

What additional resources are provided for those interested in HVAC and refrigeration training?

The video provides links in the description section to a multimeter and a refrigerant charging book, as well as support for the HVAC training channel, subscription options, and additional HVAC related videos.