Communication process with our customer in Egypt about the overload limiter

On March 1, we received an inquiry from an Egyptian customer. The customer said that they currently have 6 overhead cranes that have installed overload limiters, but there is no display so they can’t display the numbers. To be more convenient and intuitive, the customer wanted to look for an overload limiter with a display. After understanding the general needs of the customer, we replied to the email to confirm some of the parameters of their existing cranes. In the process of communicating with the customer, the customer sent a photo of their existing crane, after confirming with our engineer, we chose the overload of the BCQ-GL model for the customer and sent the detailed technical parameters to the customer.

We have this type of overload limiter in stock, so after receiving the payment from the client, we arrange the transportation immediately. And before delivery, our factory will do the related test and debugging, to make sure that the limiter can be used directly when it arrived at the customer’s side. Due to the dimension of the overload limiter being very small, so the customer decided to transport the limiter by DHL. Below is the delivery picture.

Instruction for BCQ-GL type overload limiter

Overview

BCQ-GL type weight limiter is a professional safety protection device for lifting machinery, especially used for various types of electric hoist and single beam cranes. The device has the functions of sound alarm, immediate alarm, cutting off the lifting motor circuit of the crane and displaying the lifting weight, etc., which can avoid the equipment and personal accidents caused by overloading and overloading of the lifting equipment. Therefore, it is of great significance to the modernization and safety production of metallurgy, machinery, mining, railway, wharf, warehouse, and other industries. The product is designed with advanced computer technology, automatic check inspection and zero automatic tracking ability, with strong function, compact structure, convenient operation calibration, stable work, convenient installation, and maintenance advantages.

The main characteristics of the limiter

• Due to the use of advanced anti-interference devices and unique software design, the device has a strong anti-interference ability.
• To facilitate installation, each component of the device has been adjusted in the factory with precision instruments according to technical standards, and debugging is generally not necessary during on-site installation (see installation and Debugging).
• To facilitate the accurate display of the stable value, the limiter adopts the software adjustment memory technology, convenient and intuitive adjustment.
• Scope of application: 0.5T ~ 32T various specifications of electric hoist single beam crane.
• System error: less than ±5%(F·S).
• Alarm mode: audible and visual alarm

1). Alarm point: when the lifting weight reaches 90% of the rated lifting weight, an intermittent alarm sound (short sound) will be issued to show the weight of the heavy object;

2). Rated value alarm: when lifting weight reaches 100% of rated lifting weight, an intermittent alarm sound (long sound) will be issued to show the weight of heavy objects;

3). Immediate alarm: when the lifting weight reaches 110% of the rated lifting weight, a continuous alarm sound, red indicator light, and automatically cut off the crane lifting contactor power supply, display the weight;

• Static strength of the sensor: the static strength of the sensor is 1.5 times of the rated load;
• Operating temperature: -20℃ ~ +60℃;
• Relative humidity: 45% ~ 95%;
• Power supply voltage: AC380V, 50HZ, or according to user requirements;
• Relay contact capacity: relay contact capacity is AC380V, 2A;
• Controller voltage: 2000V;
• Display mode: four LED(red) digits display the lifting weight, with two decimal points

The working principle

The BCQ-GL lift limiter consists of two main parts, the sensor, and the controller. When the lifting machine lifts heavy weight, the weight is transferred to the sensor.  The sensor produces a slight voltage change, which is amplified by the instrument amplifier and turned into a digital signal by the high-resolution A/D converter. The digital signal is read directly by a monolithic computer and converted to a weight value after processing. The value is compared with the rated value such as 110% of the output of a pair of passive relay contact signals (normally closed), used to cut off the power supply of the lifting motor, in addition, the weight value can be sent to the controller according to the command of the controller to show the rated weight, lifting weight warning and alarm sound.

Installation and debugging

• Installation of the sensor: the elastomer is pressed against the wire rope during installation, and then the pressure plate is set on the U-shaped bolt to press the wire rope by hand. Then the left and right nuts are tightened to press the wire rope with a wrench so that the diameter of the wire rope is slightly deformed. Finally, a nut is added on the left and right sides and tightened to prevent loosening. Too tight or too loose will make the sensor output signal inconsistent.
• Installation of the controller: the controller can be installed on the switch or in the driver’s room according to different needs. The controller and the sensor are connected with a four-core shielded wire, which has been equipped at the factory. The length of the wire can be determined according to the user’s requirements, and the user can also be equipped with an aviation plug to assemble the line by himself.
• Connection: The lifting weight limiter adopts a four-core shielded cable. The two lines marked “power” (red and black) are connected to AC 380V. The two lines marked “normally closed” (blue and yellow) are connected in series in the lifting contactor circuit. Note: Power supply voltage ~ 380V. The control contact is normally closed.

Instrument Setting description and precautions

• The sensor and controller are connected through the aviation plug-in.
• 2.boot display current range – 0.5 -; Two seconds to go into a Indicates that the current range is 0.5T range.
• Hold down the “” button for more than two seconds to display the current range. Press the” “button to change the range, and the range can be cyclically changed as follows: – 0.5 -; – 1.0 -; – 2.0 -; – 3.0 -; – 5.0 -; – 10 -; – 16 -; – 20 -; – 32 -; After selecting the range, press “” and” “at the same time to save its range.
• When there is no weight on the hook, it should display “0000”. If there is a value display, press “” key to peel.
• When lifting a certain cargo, display a certain value. If it is inconsistent with the actual cargo weight, press the “” key to correct. For example: lifting 2T cargo, 1.8T display, press the “” key, through” “and” “to cooperate, input” 02.00 “, press the “” key to exit, the instrument will display 2.0T.
• The alarm value will automatically change with the range change, respectively 90%, 100%, and 105%, users do not need to set.

If you have any questions, please feel free to contact us.