The electrical system of acamión grúaplays a vital role in enabling communication between the operator and the machine, monitoring the crane’s operating conditions, and ensuring its safe performance. The crane’s dashboard is particularly important for monitoring critical components like the engine, brakes, and other essential systems related to the crane’s movement and lifting capabilities. Any incorrect readings on the dashboard can mislead the operator into making potentially dangerous actions. This is especially important for heavy-duty machines like the truck crane, where the accuracy of the instruments and understanding how to use and troubleshoot them is crucial for safety and performance.
The QY seriescamión grúas produced by Xuzhou Heavy Machinery Factory use a 24V DC electrical system (12V DC for the QY8 model), featuring a single-wire system with a negative-ground configuration. Below, we outline common faults and troubleshooting procedures for the key instruments on the QY seriescamión grúas.
1. Fuel Gauge: Monitoring Engine Fuel Levels
The fuel gauge plays an important role in monitoring the amount of fuel available for the crane’s engine. It helps ensure the crane is operating within the fuel limits required for the job.
Normal Operation:
When the ignition is off, the needle should point below the “O” mark (empty).
Once the ignition is turned on, the needle should point to the actual fuel level, with the following indicators:
“O” indicates empty.
“1/2” indicates half-full.
“1” indicates full.
Fault Conditions:
A) The needle is below the “O” mark after turning on the ignition.
Possible causes:
No power to the fuel gauge.
Wiring issues in the gauge coil.
Disconnection in the sensor connection line.
Faulty fuel sensor.
Troubleshooting steps:
Step 1: Turn on the ignition and check if the fuse is intact. If blown, replace it. If the fuse is fine, use a multimeter to measure the voltage at the positive terminal of the fuel gauge. If there is no voltage, this indicates a wiring fault. Inspect connectors for loose connections or check for broken wiring. Tighten connectors or rewire as necessary. If the voltage is 24V and the problem persists, proceed to the next step.
Step 2: Using a short wire, temporarily ground the signal terminal of the fuel sensor (float), and observe the gauge. If the needle moves towards the full mark, it indicates the gauge and wiring are functioning correctly. If so, check the ground connection of the fuel tank. If the tank is grounded properly but the issue persists, the sensor might need to be replaced or repaired.
Step 3: With the power on, ground the “S” terminal of the gauge. If the needle moves towards the full scale, the gauge is working properly, and the issue may lie with the sensor. If the needle does not move, replace the gauge.
Step 4: If both the sensor and gauge are functioning properly, use a short wire to connect the “S” terminal of the gauge to the signal terminal of the fuel sensor. Move the sensor float, and observe the gauge. If the gauge functions normally, the issue lies with the wiring. Inspect connectors and wiring for faults and correct as needed.
B) The needle is above the “1” mark after turning on the ignition.
Possible causes:
The fuel sensor is shorted.
Ground wire connection (“G” terminal) is poor.
Broken coil in the fuel gauge.
Troubleshooting steps:
Step 1: Use a multimeter to measure the resistance between the sensor connection and the flange. If the resistance is zero, the sensor is shorted to ground. If not, proceed to the next step.
Step 2: Using a short wire, directly ground the “G” terminal of the gauge. If the gauge works correctly, the issue lies with the ground connection. Check the connectors and wiring for any loose or broken parts and correct them. If grounding does not resolve the issue, the coil in the fuel gauge is likely damaged, and the gauge will need to be replaced.
2. Water Temperature Gauge: Monitoring Engine Coolant Temperature
The water temperature gauge helps to monitor the temperature of the engine’s coolant, preventing overheating and ensuring that the engine operates within a safe temperature range.
Normal Operation:
With the ignition off, the needle should remain below “40°C.”
When the ignition is turned on, the needle should indicate the actual temperature of the engine coolant.
Fault Conditions:
A) After the engine starts, the water temperature gauge remains stuck at below 40°C regardless of coolant temperature.
Possible causes:
No power to the gauge.
Sensor disconnection.
Broken coil in the gauge.
Disconnected wiring between the sensor and the gauge.
Troubleshooting steps:
Step 1: Turn on the ignition and check if the fuse is intact. If the fuse is blown, replace it. If the fuse is good, use a multimeter to check the voltage at the positive terminal of the water temperature gauge. If no voltage is present, inspect the wiring and connectors for any faults, such as loose connections or broken wires. Tighten or repair the wiring as necessary. If voltage is normal and the fault persists, proceed to the next step.
Step 2: Check the continuity of the sensor wiring. If the wiring is intact, temporarily connect the sensor signal wire to the ground. If the needle moves towards the maximum temperature reading, the gauge and wiring are functioning correctly, and the issue is likely with the sensor. Replace or inspect the sensor for faults.
Step 3: If grounding the sensor does not result in a normal needle movement, the gauge itself may be faulty, and the gauge should be replaced.
3. General Troubleshooting for Electrical Faults in the Crane’s System
In addition to the issues with the fuel and water temperature gauges, the electrical system of a truck crane may experience a variety of other faults. Here are general troubleshooting procedures for electrical problems:
1. Fuse Issues:
If the electrical system is not functioning properly, a blown fuse is a common cause. Always check the fuses before proceeding with any further troubleshooting. Replace any blown fuses and retest the system to ensure the issue is resolved.
2. Connector and Wiring Issues:
Loose or damaged connectors can disrupt the operation of various electrical components. Visually inspect all connectors, including those for the dashboard instruments, sensors, and other electrical devices. Ensure all connectors are securely fastened and that wiring is intact, with no visible damage or wear.
3. Sensor Malfunctions:
Sensors, including the fuel sensor and water temperature sensor, are vital to the proper functioning of the truck crane’s electrical system. If any sensor is malfunctioning, it can cause incorrect readings on the dashboard. Test each sensor according to the manufacturer’s specifications, and replace any faulty sensors as needed.
4. Faulty Control Panel or Dashboard:
If the display on the dashboard is malfunctioning, the issue may lie with the control panel or instrument cluster. Use diagnostic tools to check for any faults in the control panel. Si es necesario, replace the control panel or the faulty components.
Conclusión
The electrical system of the QY series truck cranes plays a critical role in monitoring and controlling the crane’s operation. Properly understanding how to troubleshoot and resolve common faults with key components, such as the fuel gauge and water temperature gauge, is essential for maintaining safe and efficient crane operation. Siguiendo los pasos de solución de problemas descritos anteriormente, operators can quickly identify and resolve common issues, minimizing downtime and preventing more severe mechanical failures. Mantenimiento regular, inspections, and attention to detail are key to ensuring the long-term reliability and safety of the crane.
