When procuring a transformer turns ratio tester, comparisons should be made in terms of measurement range, vector group support capability, tap changer testing functions, and data management methods. Different models have configuration differences in range coverage, Z-type transformer adaptability, and automatic tap position identification, and the selection should be determined based on substation maintenance procedures and the specific parameters in the transformer ledger.
The DRD-7000B turns ratio tester has a turns ratio measurement range of 1–10000, covering the common turns ratio intervals from distribution transformers to main transformers. Compared with models that only support 1–1000, this range can reduce the operational step of replacing the instrument because the value exceeds the range. The instrument adopts single-chip microcomputer control, and the large-screen LCD can display three-phase turns ratio, error, and tap position information. During procurement, it is necessary to verify the match between the nameplate turns ratio of the transformer to be tested and the instrument range.
Transformer vector groups include conventional types such as Yyn0, Dyn11, and YNd11, and some equipment uses Z-type connections. The DRD-7000B is suitable for turns ratio testing of transformers with multiple vector groups, including Z-type, and can automatically identify the group and calculate the corresponding turns ratio value. For units that simultaneously undertake distribution and main transformer maintenance tasks, this adaptability can reduce the variety of instruments needed. Before procurement, it is advisable to compile statistics on the vector group types of transformers in operation and confirm the instrument's vector group coverage.
When a transformer tap changer has many positions, measuring and recording position by position is a heavy workload. The DRD-7000B is designed with a longitudinal tap winding testing function, which can automatically determine the tap position and store the corresponding turns ratio value. This function is suitable for maintenance and handover tests of on-load tap changers. The data storage method and export interface need to match the unit's test report management system, and a data format description can be requested during procurement.
This instrument is used for turns ratio tests during transformer manufacturing and maintenance, and applicable scenarios include substation maintenance, transformer factory tests, and preventive tests. Key points for procurement verification include: whether the turns ratio range covers the equipment to be tested, whether the vector groups meet the types of transformers in operation, whether the tap testing function conforms to the maintenance process, and whether the LCD display and operation logic facilitate on-site recording. It is recommended to determine the quantity and configuration based on the annual transformer maintenance plan.
