What should be done when an excavator encounters an electrical fault?

Lighting lamp malfunction

When the lighting lamp of an excavator malfunctions, it is mainly caused by the failure of the high-voltage fuse and circuit faults. Generally, when a high-voltage fuse burns out, it will cause the lighting lamp to not light up or turn red. Fans can use a multimeter to accurately judge the fuse's blowing condition. If it is found that it has burned out, a high-voltage fuse of the same specification should be directly replaced.

When the high-voltage fuse is working normally, if the lighting still does not light up or flickers, a circuit fault check should be carried out. The causes of circuit faults are rather complex and diverse. It is also necessary to use a multimeter to troubleshoot the lighting circuit from simple to easy. At this point, the main checks should be the voltage value of the wiring harness plug (around 25V is normal), the resistance value of the lighting relay (around 320 ohms is normal; if the resistance value is too high, it indicates that it has blown), and the contact condition of the lighting switch.

Sometimes, there are also problems such as damaged bulbs, aged wires, and transformer malfunctions. Just identify the fault points and replace the corresponding components in a timely manner. In addition, there may also be some details that have not been handled properly, such as the bulb not being tightened or the socket being loose, which also need attention.

Lead-acid battery malfunction

Batteries provide continuous and stable electrical energy for equipment startup and electrical appliances. Common faults of lead-acid batteries can be classified into external faults and internal faults.

External faults mainly refer to the damage to the battery casing and the sealing port caused by long-term use, climatic reasons or chemical corrosion. To prevent such faults, it is necessary to keep the battery clean and tight to avoid the leakage of electrolyte.

The internal faults of storage batteries mainly manifest in aspects such as sulfation of the plates, shedding of active materials on the plates, short circuits on the plates, and reduction of faulty electrolyte. When maintaining and servicing the battery, it is necessary to check the density of the electrolyte and the height of the liquid level, and ensure proper charging. This can effectively prevent the above situations from occurring.

Failure of the starting system

The starting system is mainly composed of components such as the battery, starter, starting switch, and starting relay, which is responsible for converting electrical energy into mechanical energy to drive the engine to start. There are generally three situations of starting system faults:

(1) The starter does not rotate

The main causes of the starter not rotating fault are five: power supply failure, starter failure, starting relay failure, ignition switch failure, and circuit failure.

(2) The starter is weak when starting

When the starter starts with a low speed or stops rotating, it can be determined that the starter has weak starting power. The causes of the failure include power supply failure (battery), starter failure, transformer failure, and damage to rectifier components. The inspection method for this phenomenon is the same as above. Just replace and repair it in time.

(3) The starter idles

When the starter malfunctions, the phenomenon of the starter idling may also occur. At this time, the starter rotates very fast but does not drive the crankshaft of the engine. This indicates that the starter and the circuit and other parts are normal, and the fault point lies in the transmission part. When the gears and flywheel rings of the transmission device are severely worn, they will not mesh, resulting in idling. At this time, they should be replaced and tightened in a timely manner to ensure the meshing degree of the machinery.

The above three types of starting system faults are observable faults. If the starter itself is faulty, it needs to be disassembled for inspection.