The start relay is a critical component in a refrigerator’s compressor system, ensuring the motor starts and runs efficiently. Without a functioning start relay, the compressor may fail to start, leading to cooling problems. This article provides a detailed, professional guide on where to find the start relay on a refrigerator compressor, its function, types, and troubleshooting tips.
Understanding the Role of the Start Relay
- Motor Starting Assistance: The compressor motor requires a high initial torque to start. The start relay provides the necessary electrical boost.
- Switching the Start Winding: Once the motor reaches a certain speed, the relay disconnects the start winding to prevent damage.
- Overload Protection: Some relays include overload protectors to shut off power if the motor overheats.
Types of Start Relays in Refrigerator Compressors
PTC (Positive Temperature Coefficient) Relay
- How It Works: Uses a thermistor that heats up when current flows, increasing resistance and cutting off the start winding.
- Location: Typically attached to the compressor’s side or housed in a plastic casing near the terminals.
Electromagnetic (Current-Type) Relay
- How It Works: Uses a coil and magnetic switch to engage/disengage the start winding based on current flow.
- Location: Mounted directly on the compressor terminals or in a relay box nearby.
Solid-State Relay (Modern Models)
- How It Works: Uses electronic components instead of mechanical parts for more reliable operation.
- Location: Usually integrated into the control board or placed near the compressor.
How to Test a Faulty Start Relay
Visual Inspection
- Check for burn marks, melted plastic, or loose wires.
- A swollen or cracked PTC relay indicates failure.
Shake Test (For Electromagnetic Relays)
- Shake the relay: if you hear rattling, the internal contacts may be damaged.
Common Symptoms of a Bad Start Relay
- Clicking sound but compressor doesn’t start
- Refrigerator not cooling
- Compressor overheating
- Frequent cycling on and off
Replacing the Start Relay
- Purchase the correct replacement (match model number).
- Disconnect the old relay by unplugging or unscrewing it.
- Install the new relay in the same orientation.
- Reconnect power and test the refrigerator.
Preventive Maintenance Tips
- Keep the compressor area clean (dust can cause overheating).
- Check wiring periodically for corrosion or damage.
- Avoid frequent power surges (use a voltage stabilizer if needed).
Conclusion
The start relay is a small but crucial part of a refrigerator’s compressor system. It is typically located near the compressor terminals, either mounted directly or housed in a protective casing. Identifying, testing, and replacing a faulty relay can restore cooling performance and extend the appliance’s lifespan. Always follow safety precautions and consult a professional if unsure.
By understanding where the start relay is and how it functions, technicians and DIY enthusiasts can efficiently diagnose and resolve compressor-related issues in refrigerators.
