WRT-10D Winding Resistance Tester with Demagnetisation The WRT-10D is a high performance winding resistance tester designed for power transformers and large motor applications. COMPETITIVE ADVANTAGES Rugged, highly regulated and filtered out put current source for fast stabilized mea surements Winding resistance testing is an important part of a power transformer maintenance or a manufacturing quality assurance program. Transformers & large motors are subject to vibrations, overloading and environments with large temperature variations. Winding resistance measurements can assure that the connections are made correctly and that no opens or shorts are present. Tap changers of power transformers are a particularly critical element of a power system. The WRT-10D is very effective in detecting Tap changer abnormalities. High Accuracy 0.1% of reading High resolution with 4 ½ display, 0.1µΩ Large, Color LCD display Full QWERTY keyboard for easy data entry Large internal memory Reporting software automatically generates a finished report from PC Built-in thermal Printer Remote Tap Changer circuit The WRT-10D injects a DC current through the windings & measures the voltage drop. The instrument calculates the resistance R= E / I. The challenge in winding resistance measurements is that the voltage across an inductor is defined by V= L (di/dt), where L is the inductance of the winding & (di/dt) is rate of change of current. Therefore small changes in the current, as may be caused by ripple or poor regulation, can make it impossible to measure the DC resistance. The highly regulated and filtered current output of the WRT-10D allows for winding resistance measurements on very large power transformers. Stabilized reading indicator Protection against overvoltage transients Timed mode for logging heat run testing Multi-language interface Housing internal storage compartment for accessories or leads WRT-10D Winding resistance tester with demagnetisation circuit ndb Technologies inc. • 1405 St-Jean-Baptiste, office 111 • Quebec (QC) G2E 5K2 - Canada • Tel: 1(418)877-7701 Fax: 1(418)877-7787 Email: [email protected]

TECHNICAL SPECIFICATIONS Power input Fuse rating Test current Test voltage Resistance measurements Resistance range • Against overvoltage transients and substation noise • High speed current interruption detector • Audible warning during testing and discharging • Emergency off button ± 0.1% reading ± 0.025% Full scale Measuring ranges • 10A Range 1 : 0.1 µΩ to 1.9999 mΩ Range 2 : 1.0 µΩ to 19.999 mΩ Range 3 : 10 µΩ to 199.99 mΩ Range 4 : 0.1 mΩ to 1.9999 Ω • 1A Range 1 : 1.0 µΩ to 19.999 mΩ Range 2 : 10 µΩ to 199.99 mΩ Range 3 : 0.1 mΩ to 1.9999 Ω Range 4 : 1.0 mΩ to 19.999 Ω • 0.1A Range 1 :...