Voltage transformer NMT series for installation on electric locomotives

Measuring voltage transformers NMT are designed to convert the high voltage of the contact network with a rated voltage of the primary winding of 25 kV, 50 Hz AC and 3 kV DC, into a low, galvanically isolated voltage for supplying metering, protection and signaling devices, for measuring the magnitude of the voltage of the contact network electric locomotive control system and traction converters.

Measuring voltage transformers NMT are designed for installation on the roof of electric locomotives, so they can work in conditions of vibration, high overloads, as well as sudden changes in temperature and climatic zones.

According to the principle of operation, they are inductive, single-phase, single-pole, grounded. Voltage transformers (VT) have a cast housing made on the basis of an epoxy compound. The insulation material of voltage transformers has excellent arc, ozone and ultraviolet protection characteristics, while it has high mechanical strength, so that the transformers can work for more than 20 years without any maintenance.

MAIN SPECIFICATIONS

Rated primary voltage from 3 to 36 kV
Rated secondary voltage 100.403
Number of secondary windings up to 3
Winding accuracy class for measurement 0.2; 0.5
Winding accuracy class for protection 3P;6P
Voltage factor 1.2
Ambient conditions: temperature from -60° to +70°

ADVANTAGES OF CAST RESIN VOLTAGE INSTRUMENT TRANSFORMERS

Lack of any maintenance throughout the entire period of operation
Fire and explosion-proof design
Long creepage distance
High loads for all accuracy classes
Low partial discharge (PD)
The hydrophobic material exhibits excellent outdoor performance and also minimizes the possibility of arcing.
No ozone depleting gases

Transformers meet the requirements of IEC, ANSI, IEEE, GOST standards.