Check the starter potential when the motor is under load. The allowable voltage fluctuation range is ±10%.
Low voltage can severely impede the normal operation of the lifting platform. The electrical components, especially the motor, rely on a certain voltage level to generate sufficient torque. If the voltage drops below the acceptable range, the motor may struggle to start or operate smoothly. This is because the magnetic fields generated within the motor, which are crucial for its rotational force, weaken as the voltage decreases. In industrial settings, voltage fluctuations can occur due to heavy equipment sharing the same power grid, or during peak electricity consumption periods. Monitoring the voltage during motor load operation is essential, and using devices like voltmeters at key points in the electrical circuit can help detect such issues early.
2. Motor Does Not Rotate
Inspect the motor and the electrical circuit.
When the motor fails to rotate, there could be multiple underlying causes. It might be due to a simple wiring fault, such as a loose connection or a broken wire. Electrical circuits can also be affected by environmental factors, like moisture causing short circuits or corrosion degrading the conductivity of the wires. Additionally, internal motor problems, such as a seized bearing or a damaged winding, can prevent the rotor from turning. A thorough inspection involves not only visually checking the wiring and connections but also using electrical testing equipment, like multimeters, to measure resistance and continuity in the circuit, and mechanical checks to assess the motor’s moving parts.
3. Motor Reverses Rotation
Randomly swap two of the three-phase wires.
The rotation direction of a three-phase motor is determined by the phase sequence of the electrical supply. Incorrect wiring can lead to reverse rotation, which is highly undesirable as it can cause the lifting platform to operate in an unexpected and potentially dangerous manner. By interchanging any two of the three-phase wires, the phase sequence is altered, correcting the motor’s rotation direction. This is a relatively straightforward fix but requires caution, as working with live electrical wires demands proper safety precautions, including wearing insulated gloves and turning off the power supply before making any changes.
4. Motor Phase Loss (Motor Does Not Move and There Is a Buzzing Sound)
Check the circuit breaker and the motor wiring.
Phase loss occurs when one of the three electrical phases supplying power to the motor is interrupted. This can be due to a tripped breaker, a damaged wire, or a poor connection. When this happens, the motor cannot generate a uniform rotating magnetic field, resulting in it remaining stationary and emitting a characteristic buzzing sound. Inspecting the circuit breaker involves checking for any signs of overheating, tripping, or damage. The motor wiring needs to be traced carefully, looking for any visible breaks, loose connections, or signs of electrical arcing.
5. The Descent Valve Is Open
With the descent button released, use a voltmeter to check if the descent valve is powered. If there is no power, check the wiring and troubleshoot the fault; if there is power, troubleshoot the fault of the descent valve itself. The spool of the descent valve must be kept clean and move freely.
The descent valve plays a crucial role in controlling the movement of the lifting platform. If it remains open when it shouldn’t, hydraulic fluid can flow in the wrong direction, preventing the platform from rising. A malfunctioning valve could be due to electrical issues, such as incorrect wiring or a faulty solenoid, or mechanical problems like dirt or debris obstructing the spool’s movement. Regular cleaning and maintenance of the valve, along with proper electrical checks, are necessary to ensure its reliable operation.
6. Low Pressure in the Relief Valve
Readjust the relief valve. Adjust it under 100% rated load.
The relief valve is designed to protect the hydraulic system from overpressure. However, if it is set too low, it can limit the pressure available for lifting operations. In a hydraulic lifting system, pressure is directly related to the force exerted on the piston to raise the platform. Incorrectly adjusted relief valves can lead to insufficient lifting force, causing the platform to fail to ascend. Adjusting it under full rated load conditions ensures that the valve is set to allow for adequate pressure during normal operation while still providing protection against excessive pressure spikes.
7. Low Oil Level, Pump Suction of Air
Fill the hydraulic oil to the proper level.
Hydraulic oil is the lifeblood of the lifting platform’s hydraulic system. A low oil level can cause the pump to suck in air instead of oil. Air in the hydraulic system is highly compressible compared to oil, which means that when the pump tries to generate pressure, the air pockets compress instead of transmitting the force effectively. This results in a loss of lifting power and can cause erratic operation. Regularly checking and maintaining the oil level, as per the manufacturer’s specifications, is vital for smooth operation.
8. Suction Filter Blockage
Clean the filter.
The suction filter is responsible for preventing contaminants from entering the hydraulic pump. Over time, debris, dirt, and metal particles can accumulate in the filter, restricting the flow of hydraulic oil. A blocked filter forces the pump to work harder to draw in oil, which can lead to reduced performance, cavitation (formation of vapor bubbles), and ultimately, damage to the pump. Cleaning the filter at regular intervals, or replacing it when it becomes too clogged, helps maintain the integrity of the hydraulic system.
9. Air Leak in the Suction Section
Inspect the oil suction pipe and joints; tighten the joints. Replace the joints if necessary.
Air leaks in the suction section can introduce air into the hydraulic system, similar to the issue with a low oil level. Even a small air leak can disrupt the smooth flow of hydraulic oil and reduce the system’s efficiency. The joints between pipes are common areas for leaks, especially if they are not properly tightened or if the seals have deteriorated. Visual inspections, along with pressure tests, can help identify these leaks, and prompt action, such as tightening or replacing the faulty components, is required to fix the problem.
10. The Indicator Light Is On, the Motor Rotates When the Ascent Button Is Pressed, but the Lifting Platform Does Not Rise
Check the ≥-phase power contact. If the power is connected in reverse, the motor will reverse. Just correct the power connection.
This situation indicates that while the motor is receiving power and functioning, there is an issue with the power supply’s phase connection that prevents the lifting force from being effectively transmitted to raise the platform. Incorrect phase connection can disrupt the synchronous operation of the motor and the hydraulic components, causing the platform to remain stationary. By carefully examining and correcting the power connection, the normal lifting operation can be restored.
In addition to these common troubleshooting steps, regular preventive maintenance is of utmost importance for the long-term reliable operation of the lifting platform. This includes comprehensive inspections of all mechanical components, such as checking for wear and tear on pistons, cylinders, and linkages. Lubrication of moving parts should be carried out at regular intervals to reduce friction and extend the lifespan of components. The electrical system should be periodically tested for insulation integrity, and all safety features, like emergency stop buttons and limit switches, need to be verified for proper functioning. Advanced diagnostic tools, such as hydraulic pressure sensors and vibration analyzers, can also be employed to detect potential issues before they escalate into major failures. Staff training is another crucial aspect, ensuring that operators are aware of proper operating procedures, safety precautions, and basic troubleshooting techniques, so that they can respond promptly in case of any malfunctions.
