Troubleshooting Common Resistor Failures in Industrial Equipment

Resistors are components designed to limit current flow, adjust signal levels, and dissipate excess energy across a wide variety of electrical systems. In industrial environments, where systems often operate under continuous stress and fluctuating conditions, these parts are frequently subjected to stressors that can accelerate degradation and contribute to eventual failure. This blog outlines common resistor failure symptoms and presents practical strategies for accurate diagnosis, so read on if you would like to learn more. 

Common Symptoms Indicating Resistor Malfunction 

• Unexpected Readings: A sudden change in circuit voltage or current may indicate that a resistor's value has moved outside its defined tolerance range. 
• Noise and Signal Instability: Malfunctioning resistors in signal processing circuits can result in noise spikes or erratic output.
• Open Circuits: In some cases, resistors may fail entirely and cease to conduct, resulting in partial or total loss of system functionality.
• Visible Damage: Cracks, burns, or delamination on resistor surfaces can be indicative of thermal or mechanical failure modes.
• Overheating Components: A resistor operating beyond its rated wattage may become excessively hot, sometimes producing a burning odor or discoloration.

Common Failure Modes and Their Root Causes 

• Thermal Overload: Inadequate heat dissipation can result in elevated internal temperature and may contribute to material degradation.
• Mechanical Stress: Vibration, shock, or mounting errors during installation can fracture internal connections and lead to performance issues.
• Corrosion and Oxidation: Moisture intrusion may lead to the degradation of conductive pathways, particularly in carbon-film or wire-wound resistors.
• Electrical Overstress (EOS): Transients or sustained overvoltage events may cause permanent shifts in resistance values or create open circuit conditions.
• Manufacturing Quality: The use of poor-quality solder joints or substandard materials may shorten a resistor’s service life.

Testing and Diagnostic Techniques for Industrial Resistors 

• Multimeter Testing: A digital multimeter can measure resistance to identify open or shorted resistors with minimal delay.
• Thermal Imaging: Infrared cameras are engineered to detect hotspots, indicating when resistors may be functioning beyond their safe thermal limits.
• In-Circuit Testing: In-circuit resistance measurements allow personnel to assess resistor performance without the need to remove the component from the circuit.
• Visual Inspection: Skilled technicians should conduct visual inspections under magnification to identify potential issues like corrosion, swelling, or surface cracks when suspected.

Preventing Future Resistor Failures

• Correct Sizing: It is crucial to choose resistors with a power rating that exceeds anticipated operating conditions to limit the risk of overheating.
• Dependable Suppliers: Buyers should source resistors from distributors that demonstrate consistent reliability and are recommended by numerous industry professionals.
• Environmental Protection: Conformal coatings or sealed resistor types should be used in environments where moisture, chemicals, or dust are expected to be present.
• Routine Inspections: Scheduled checks should be performed with thermal cameras and multimeters to identify potential signs of early degradation.

Industrial Spares Distribution: Your Source for Reliable Resistors