When comparing different options, procurement personnel often focus on the initial price and nominal parameters, while the hidden costs in the maintenance phase are easily overlooked. The DRD-50A DC Resistance Tester is designed for DC resistance measurement of transformers, instrument transformers, switches, and other equipment, providing an evaluable basis for on-site maintenance costs from aspects such as consumable versatility, calibration cycles, and troubleshooting convenience.
At substation maintenance sites, transformer winding DC resistance testing is a routine item for determining inter-turn short circuits in windings and poor contact of tap changers. The DRD-50A provides a measurement range of 1μΩ to 2kΩ, with output current ranges covering 5A, 10A, 20A, and 50A, which can be switched according to the rated capacity of the winding to reduce measurement deviations caused by current mismatch.
The contact resistance of circuit breaker main contacts, disconnector contact fingers, and busbar connection points directly affects current-carrying capacity. The instrument supports four-wire measurement and, with dedicated test clamps, can quickly detect switch contact resistance. After the test current stabilizes, the resistance value is automatically locked to avoid the dispersion of manual readings. For application scenarios of a 200A loop resistance tester, higher current requirements can be met through an external expansion module.
It is also suitable for DC resistance measurement of current transformers, voltage transformers, and small and medium-sized motor windings. The instrument has built-in inductive load discharge protection. After the test is completed, the winding is automatically safely discharged, reducing the risk of operators touching residual voltage. The display interface simultaneously presents resistance value, test current, and ambient temperature, facilitating on-site recording and comparison.
As a smart loop resistance tester, the DRD-50A supports storage and query of measurement data, can save multiple sets of test records, and can export them to a computer via a USB interface. Procurement personnel can use this to evaluate the labor input in data entry and report preparation, as well as whether additional analysis software needs to be configured.
The working power supply is AC 220V±10%, 50Hz, adapting to most maintenance power environments. The instrument adopts a portable structure and weighs about 6kg, making it easy to move and use in switch rooms, transformer areas, and other locations. The cooling method is natural cooling, reducing the replacement frequency of wearing parts such as fan filters.
