Three-Phase Voltage Transformer Group 3хЗНОЛ(П)-НТЗ for Isolated Neutral Networks

Earthed single-phase and combined voltage transformers ZNOL(P)-NTZ, assembled in a three-phase group, are used in networks with isolated neutral. The transformers can be designed with one or two main secondary windings intended for measuring/measuring and one additional winding intended for supplying the circuits of protective devices and monitoring the network insulation. The neutral earthing of three-phase transformers allows the mains insulation to be monitored by means of additional secondary windings connected in open delta. The necessity of the mains insulation monitoring function dictates the use of earthed voltage transformers.