DTU distribution terminals and instrument transformers are key components of distribution automation systems. They are produced in large volume with many models and many test items, which makes them typical precision assembly and testing intensive products. Taizhou Yufeng Intelligent Equipment Co., Ltd. planned a DTU assembly and instrument transformer production and testing flow line for distribution automation manufacturers, combining component screening, assembly, testing and data management into a standardized process.
DTU assembly station design
The DTU assembly line is organized into component pre-inspection, PCB assembly, enclosure assembly, wiring and fastening, power-on testing and burn-in testing stations. The component pre-inspection station samples and sorts incoming parts to prevent defective components from entering assembly. The assembly stations use anti-static facilities and locating fixtures, and connector insertion, fastening and cable connection follow work instructions with QR code confirmation at critical processes.
Instrument transformer assembly and testing
The assembly focus of current and voltage transformers is the winding, core and insulation treatment. Winding uses dedicated winding equipment with the number of turns controlled and recorded by a counter. After core assembly, excitation characteristics are measured. Insulation treatment follows the process, and finally the transformation ratio, polarity, accuracy and insulation tests are performed. Test data is bound to the product number, so the factory parameters of every transformer can be traced.
Insulation and accuracy testing
Insulation testing includes power frequency withstand voltage, insulation resistance and partial discharge. The test stations set parameters and judge pass or fail automatically according to product standards. Accuracy testing uses a standard source and comparison meters to record the error automatically and judge the class. Test data is uploaded to the database for batch statistics and supplier evaluation.
Aging and reliability verification
DTU and transformers undergo a burn-in test before shipment to verify stability over long operation. The aging station is managed by batch and records aging time, temperature and abnormal events. Products that pass aging enter final inspection and packing.
Line planning advice
For DTU and transformer products with many models and medium to large batch sizes, station-based assembly plus automated testing balances efficiency and flexibility. Test equipment can be configured modularly by test item, so a new test item only requires adding a module. The specific solution is customized according to the product list, test standard and daily output.
For a DTU assembly and instrument transformer testing flow line proposal, contact Taizhou Yufeng Intelligent Equipment Co., Ltd. for a technical evaluation.