Crane Torque Limiter and Emergency Pump Station Troubleshooting

July 14, 2022
Latest company news about Crane Torque Limiter and Emergency Pump Station Troubleshooting

Today OUCO brings you two solutions to the common failures of marine cranes.

What should I do when the load displayed on the crane torque limiter is inaccurate or zero?

  1. If the load keeps showing zero, the electrical wiring may be wrong. Do not perform load testing and Classification society inspection, in this case to avoid damage to the crane.
  2. If it sometimes shows zero, it is possible that the wiring contact is poor or the weight sensor is damaged. You need to check the location.

First, check the connection of the weight sensor on the boom head, near the aviation socket, whether the connection is loose, and whether there is poor contact caused by moisture.


marine crane aviation socket


If there is no problem, adjust the wiring and connect the junction box. Note the color of the corresponding wires.


junction box of marine crane


If the crane torque limiter still shows abnormality, you can connect the crane torque limiter and the weight sensor directly, which can determine whether the weight sensor is damaged.
Note: When the torque meter is not properly debugged, the winch motor defaults to fast mode, and in principle, it cannot lift heavy loads.

If the customer forcibly lifts heavy objects by luffing, it will cause sliding and damage the motor.

How to troubleshoot when the emergency pumping station is not working?

Tere is an important prerequisite: the emergency pump is operated on the main control box, not in the cab. After the main power is cut off, turn on the emergency power before you can operate in the main control box.
First, check whether the ball valve on the side of the emergency pump is open or closed. The emergency pump can only be started in the closed state, otherwise the pressure oil of the emergency pump will flow back to the oil tank from the “ls port”, and the pressure cannot be established.
As shown in the figure below, the ball valve is open and the emergency pump is not used.
In addition, you can check whether the emergency motor is reversed.


Keep the Ball valve open state


Disconnect the pipeline


If we cannot start the hydraulic pump after the ball valve is closed, disconnect the pipeline here.

Start the emergency pump and observe whether hydraulic oil overflows. You should connect the tubing and keep trying.

If not, we can further disassemble the fuel tank for inspection.

Disassemble the oil tank, leave some oil in the oil tank, and then disassemble the oil outlet of the gear pump to test separately.

Check if there is oil. If there is air in the oil outlet of the gear pump that needs to be discharged, it will also fail. Test again after exhausting.

If it still doesn’t work, the pump may be damaged and you can take it apart to check.

During crane use, mechanical parts, components, electrical controls and hydraulic system components wear out and cause failure.

The probable causes of the same failure are not in a one-to-one correspondence.

Therefore, in order to carefully analyze the failure and accurately find out the actual cause of the failure, we need to use the troubleshooting method for each component according to the failure point to restore the technical performance.


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