I. Basic Product Information and Supply Arrangements
We are producing Unicom outdoor single-phase distribution boxes. This product has specific specification parameters. Its rated voltage is 220V, and the rated current is 40A. The internal configuration includes one 40A 2P ABB circuit breaker and four single-pole 16A ABB circuit breakers, and it is without an electricity meter. A total of 250 distribution boxes are being produced this time, and they will be delivered in two batches.
II. Problems in the pre - production stage of the first batch: Lack of incoming inspection for the boxes
In the first batch of production, a serious early-stage loophole emerged. After the boxes were delivered, they were left in the warehouse for several days and were directly put into storage without going through any inspection process. This oversight laid a hidden danger for subsequent production problems.
III. Production and assembly issues on the 9th: Errors in base plate drilling and folding
During the production and assembly process on the 9th, when the assembly work was half - done, the quality inspection personnel found serious problems with the base plate when determining the wiring scheme. There were errors in the punching of the base plate, and the punching direction was reversed, which directly affected the subsequent wiring work. At the same time, there was an obvious discrepancy between the hemming distance and the design requirements. According to the explanation of the designers, the hemming should reach 15 cm, but the actual hemming was only 10 cm.
This kind of error has had multiple impacts. Firstly, during the grounding wire wiring, due to the insufficient flanging distance, the grounding wire has to travel a longer distance, which directly leads to the waste of wires. Secondly, the lengths of the insulator screws of the neutral bar and the grounding bar do not match the base plate with a 10 - cm flanging. The screws originally designed to fit the flanging length encountered problems when installed on the base plate with a shorter actual flanging. When fixing the base plate, one of the four screws could not be installed properly, and the screws for fixing the base plate were too short. To solve this problem, the insulator screws had to be dealt with. One set of screws was ground off the excess part with a grinder, and the other three sets had the excess length cut off with large wire - cutting pliers. This treatment process not only increased the assembly time but also wasted electrical energy. Moreover, the treated insulator segments became very difficult to disassemble later.
IV. Production issues on the 10th: Installation divergence and quality issues of bus bars
During the production process on the 10th, there was another disagreement regarding the installation method of the single busbar. In the past, the busbars were always installed in the reverse way. However, during this production, the team leader of Production Team One asked the process quality inspection personnel whether the busbars should be installed in the correct way. At that time, the process quality inspection personnel thought that as standard parts, the busbars should be installed in the correct way, so they gave wrong information. The production team leader was very efficient in execution. According to the instructions of the quality inspection personnel, he informed Production Team Three to install all the busbars in the correct way. However, when the product inspectors conducted the inspection, they thought that the busbars should be installed in the reverse way. The process quality inspection personnel also realized their mistake and required all the products to be reworked, installing the busbars in the reverse way. Finally, the production manager intervened and decided that the busbars of this batch of completed products would remain installed in the correct way, and they would be installed in the reverse way in the next batch of production.
In addition, there is also a problem that the busbars in Production Group Ⅲ are not taped and need to be reworked. It happens that this is a good opportunity to install the busbars in reverse. However, no changes were made in Production Group Ⅰ. At the same time, it was also found that there was a situation of cutting corners in the production of the busbars. The design requires that the width of the busbars should be 7mm, but the actual width of the purchased busbars is only 6.44mm. At present, it has not been determined whether there will be quality hazards due to the insufficient width. Moreover, the situation where raw materials are directly put into storage without inspection has become the norm in this production.
V. Packaging issue No. 11: Packaging quality and design defects
On the 11th, the distribution boxes were produced and then packaged and strapped. However, when the technical department conducted spot checks, many problems were found in the packaging. The appearance of the packaging was not aesthetically pleasing, the tape was not firmly adhered, and the packing straps were not tight enough. Even before leaving the factory, some of the packing straps had already come loose.
After analysis, the root cause of the problem lies in the mismatch between the design of the distribution box and the size of the packaging box. There are two metal beams inside the distribution box for fixing, but the designed size of the packaging box does not take this factor into account, resulting in the packaging box being unable to completely cover the distribution box, greatly reducing the packaging effect. In fact, this type of box has been produced three or four times, and the problem of the inappropriate size of the packaging box has always existed but has never been solved. To improve the packaging situation, it can be considered to appropriately lengthen the size of the carton lid.