Nowadays, partial discharge (PD) measurement is one of the most reliable methods to evaluate the insulation conditions of HV apparatus on local problems. The insulation is the key point of the equipment lifetime. 

Defect in insulation due to manufacture, assemble or ageing are evidenced by PD generation that accelerates the degradation process causing premature dielectric failure. 

NDB-DOC-3™ Distribution Transformer tester.

The NDB-DOC-3™ is a test instrument designed for distribution networks transformers from 5kVA to 3MVA. It can determine the presence of short circuits or open circuits in the distribution transformer primary winding & also short circuits on the secondary winding. The NDB-DOC-3™ is designed to be operated without disconnecting the transformer’s secondary windings from their loads.