High-voltage instrument transformers are specialized devices designed for the accurate measurement of current and voltage in high-voltage networks, as well as for the safe transmission of signals to relay protection systems, automation systems, and measuring instruments.

They provide electrical isolation between the high-voltage portion of the network and low-voltage control systems, protecting equipment and personnel from hazardous voltages.

Such transformers are critical components of substations, power lines, industrial power complexes, and commercial electricity metering systems.

Purpose of Measuring Transformers

Current transformers (CTs): precise current measurement, signal transmission to relay protection systems, and electricity metering.

Voltage transformers (VT/PTs): stepping down high voltage to a standard level for measuring instruments.

Combined transformers: simultaneous measurement of current and voltage.

Insulation and safety: isolation of the high-voltage section from the secondary circuits.

Grid stability: ensuring the correct operation of automation and protection systems.

Minimum and maximum technical specifications (general ranges)

Voltage class: from 6 kV to 800+ kV

Design types: oil-filled, dry-type, polymer, porcelain

Primary current (CT): from 5 A to 5000+ A

Secondary voltage (VT): standard 100/√3 V, 110/√3 V, 220/√3 V

Accuracy class: 0.1 / 0.2 / 0.5 / 1 / 5P / 10P

Installation: outdoor, indoor, in open-air substations, in switchgear

Resistance: to atmospheric influences, contamination, UV radiation, and mechanical loads

Parameters depend on the manufacturer, series, and specific application.

What We Can Supply and Provide

We supply measuring transformers of any brand—we select the optimal solution based on the facility’s technical requirements.

We design measurement and relay protection schemes, integrating CTs/VTs into high-voltage assemblies.

We perform configuration, installation, commissioning, and maintenance.

We provide a warranty covering all stages—from equipment selection to commissioning.

Warranties and Liability

We ensure that the equipment complies with international standards, monitor the quality of deliveries, and guarantee the stable operation of measuring transformers within high-voltage systems. Each stage is backed by an official warranty and technical support.