As the “nerve center” of boiler operation, if the boiler electric control cabinet malfunctions, it will not only affect the normal operation of the boiler but may also pose safety hazards. Mastering common fault types, repair methods, and preventive measures is crucial for ensuring the stable operation of the boiler.
I. Analysis of Common Fault Types and Causes
1.Circuit Open – circuit Faults
Circuit open – circuits are frequent faults in boiler electric control cabinets. In a factory case, due to a long-term lack of inspection, the outer skin of a wire connecting the heating element in the electric control cabinet aged and cracked, and the core wire gradually broke, resulting in the boiler’s inability to heat normally. In addition, loose wiring terminals are also a common cause. The continuous vibration during equipment operation can cause the terminal screws to gradually loosen, resulting in poor circuit contact. The fusing of fuses is mostly due to circuit overload or short-circuit. For example, when a load device is short-circuited, the instantaneously excessive current will cause the fuse to blow quickly and cut off the circuit.
2. Component Damage Faults
The electrical components in the electric control cabinet are in a high-load working state for a long time and are extremely prone to damage. During the frequent making and breaking of the contactor, the arc generated between the contacts continuously erodes the contact surface, resulting in an increase in contact resistance and even sticking. The electromagnetic coil of the relay heats up when energized for a long time. If the heat dissipation is poor, it may burn out. In some harsh environments, dust, moisture, and corrosive gases can accelerate the aging of components. In a chemical plant, the corrosive gas eroded the PLC module, causing it to be damaged in advance and the system to get out of control.
3.Control System Faults
Control system faults can lead to the loss of control of boiler operating parameters. In a heating station, due to a malfunction of the temperature sensor, the temperature inside the furnace could not be accurately measured. The PLC received incorrect data and wrongly increased the heating power, almost causing a safety accident. In addition, the PLC program may also become disordered or lost due to programming errors, unexpected power outages, etc., making it impossible to execute control commands normally.
II. Targeted Fault Repair Strategies
1.Repair of Circuit Open – circuits
For aged and damaged wires, they must be replaced strictly according to the original specifications, and insulating tape or sleeves should be used for insulation protection. When the wiring terminals are loose, use appropriate tools to retighten them, and if necessary, apply anti-loosening glue. Before replacing the fuse, the root cause of the circuit fault must be carefully investigated. Only after eliminating overload and short – circuit problems can a fuse with the same rated current be replaced to prevent it from blowing again.
2.Repair of Component Damage
When the contacts of the contactor are severely worn, the contacts can be replaced or the entire contactor can be directly replaced. Ensure good contact when installing. After the relay coil burns out, replace it with a relay of the same model and parameters. If the PLC malfunctions, if it is a module damage, accurately locate and replace the corresponding module; if the program is abnormal, rewrite and download the program, and conduct repeated debugging.
3.Repair of the Control System
When the sensor malfunctions, it can be calibrated first. If calibration is ineffective, a new sensor needs to be replaced. For PLC program problems, check the program logic line by line. After correcting the errors, conduct sufficient tests in a simulation environment. After confirmation, put it into actual operation. At the same time, a shielding device can be installed, and a regulated power supply can be used to reduce the impact of electromagnetic interference and power fluctuations on the system.
III. Comprehensive Fault Prevention Measures
Daily maintenance is the key to reducing faults. Regularly clean and remove dust from the electric control cabinet every month to prevent dust accumulation from affecting heat dissipation. Conduct a comprehensive inspection of electrical connections every quarter to ensure firm wiring. Test the performance of electrical components at least once a year and replace aging components with degraded performance in a timely manner. In addition, optimize the operating environment of the electric control cabinet, keep it dry and ventilated, install an air filter to isolate corrosive gases. Establish detailed equipment operation records, and through data analysis, discover potential fault signs in a timely manner and nip problems in the bud. By deeply understanding the causes of faults, mastering repair methods, and doing a good job in prevention, the reliability of the boiler electric control cabinet can be effectively improved, providing protection for the stable and safe operation of the boiler. If you encounter problems in actual operation, you are welcome to communicate and discuss at any time.
