How to use and pay attention to the weighing junction box

Brief introduction of weighing junction box:

The junction box is the connecting part of the load cell of the weighbridge and the display instrument. It plays the role of connecting and transmitting the signals of two important parts of the weighing system. Generally speaking, the junction box of the weighbridge is mostly made of metal materials, and the side of the box is arranged The sealing joint for passing through the signal cable, the common junction box is flat and rectangular, and the metal material can ensure that it has a certain anti-interference performance, which is more durable, and according to the different junction boxes of today's scale load cells and weighing display instruments There have also been changes, and common application types are analog and digital.

The Ningbo Saintbond intelligent analog junction box:

The junction box used by the analog weighbridge is analog, which can be connected to analog load cells and analog weighing display instruments. No matter how many load cells are used in the scale, they are generally connected in full parallel, and each load cell must be connected in parallel to work. The ratio of the sensitivity of the load cell to its output impedance is required to be equal, but in the actual production of the component, the difference between the sensitivity and the output impedance is inevitable, which will lead to an error in the weighing result of the weighing system, so the junction box The function is also to make the output of each load cell consistent. Therefore, from this point of view, the junction box is equivalent to a passive resistance network, and adjusting an adjustable resistance is equivalent to changing the output impedance of the load cell connected to it, so that the load cell can realize full parallel operation.

The Ningbo Saintbond intelligent digital junction box:

Weighbridge equipment is constantly developing towards digitalization, and naturally its junction box is also constantly improving. The digital junction box converts the analog signal generated by the analog load cell into a digital signal, and transmits the data to the weighing display instrument after processing. According to the difference in circuit structure, this type of junction box is divided into single A/D and multi-channel A/D forms. Single A/D is to connect multiple analog load cells to an A/D conversion circuit, and multi-channel A/D The junction box is equipped with multiple analog load cell inlets and a power communication port. It has multiple A/D conversion communications and can be connected to multiple load cells on the weighing platform. The digital junction box is an essential part of the digital weighbridge.

Installation of the weighbridge junction box:

Fix the junction box at a suitable position on the scale body, and open the top cover of the junction box. Pass the load cell cable and instrument signal cable through the corresponding interface of the digital junction box, connect all the cables according to the instructions, and tighten all the nuts after completion. The unused interface can be blocked with a sealing rubber gasket or plasticine, and the nut should be tightened at the same time. Connect the outer shields of all cables to the grounding post of the digital junction box. The installation is complete.

Analog load cells are equipped with corresponding analog junction boxes, while Ningbo Saintbond intelligent digital load cells are equipped with corresponding digital junction boxes. Do not confuse them during use, otherwise the relevant electronic components may be burned. One thing to note is that the digital junction box can be used for analog load cells, while the analog junction box can only be connected to analog load cells.

How to use and pay attention to the weighing junction box

1: The connection between the load cell and the junction box

Pass the cable of the load cell through the weighing platform, enter the junction box through the sealed joint, and connect it according to the different color codes of the four-core or six-core cables, or according to the positive and negative excitation power supply, positive and negative feedback, and positive and negative signals after measurement. on the corresponding terminals in the junction box. Bind the remaining cables of the load cell with plastic cable ties.

2: The junction box is connected to the weighing display instrument

Put one end of the special shielded cable into the junction box through the sealed joint, each core wire is connected to the corresponding terminal in the junction box, and the other end is welded to the special plug corresponding to the weighing display instrument through the metal tube, so that it can be inserted into the weighing indicator. Re-display instrument socket.

There are three points to note:

A: After the input and output lines in the junction box are connected, tighten, tighten and seal the joints, put a desiccant, and do a good job of moisture-proofing, and then the junction box board can be fixed;

B: For different weighing load cells, the input, feedback and output should be distinguished according to different color codes, and there must be no mistake;

C: For different weighing display instruments, the types of weighing display sockets and plugs used are different, and the connection methods are even more different, so don't make mistakes.

3: System grounding

The grounding of the electronic scale system is very important. It not only protects personal safety, but also ensures the stable and reliable operation of the system. The grounding measures of the system must not be underestimated. Generally, the electronic scale system has two grounding points, one is the grounding pile in the weighing room, which grounds the instrument shell; the other is the grounding of the weighing platform, and one or several grounding cables are used to connect the scale body to the grounding pile.