HV Power Transformer instrument transformers

Used for the measure of AC currents from 50
to 5 000A.

Air mounted or oil immersed (impregnated) in power transformers. Individual mounting as several independent transformers, or as a plug & play assembly. Each transformer is individually tested, then as a whole in the assembly work.

Flexible solution that can be customized to any client configuration.

These ring type current transformers are available for indoor (ORF) or outdoor use (ORFE). They have been designed to meet the requirements for metering and protection duties of:
- power transformers and auto-transformers
- HV or MV wall bushings
- GIS substation
- IPB
- Homopolar detection in neutral connections

The secondary terminals are accessible either directly in the case of indoor equipment (ORF) or through a watertight terminal box in the case of outdoor application (ORFE).

As per customer’s requirement, secondary windings can integrate time constant constraints.

These ring type current transformers are available for indoor (ORX) or outdoor use (OREX). They have been designed to meet the requirements for measuring:
- line currents
- zero-sequence currents in the neutral of power transformers
- earth fault currents in power transformers.

The secondary terminals are accessible, either directly in the case of indoor equipment (ORX), or through a watertight terminal box in the case of outdoor application (OREX). Several types of terminal boxes are available depending on the required characteristics.

Coming soon

These Current Transformers have been designed and developed in close collaboration with RTE, the French Electricity Transmission Network, to match the most stringent requirements of outdoor substations.

- Their « window type » design makes it possible to install them under Extra High Voltage (EHV) environment taking advantage of the insulation of primary (cable, GIS busducts, wall bushing, …)

- They can also be equipped with a filter capacitor to limit the high frequency voltage peaks showing during connect/disconnect cycles, or in case of fault on the network.

- CT’s of 1A secondary for outgoing line protection are equipped with a voltage limiter protecting CT against overvoltage in case of secondary open circuit.

Outdoor current transformers for the measurement of AC currents up to 4000A.

They are moulded in selfextinguishing resin and have heavy insulation as standard. They are equipped with a weatherproof terminal box fitted with 2 cable glands.

This range complies with the European standards EN 50014 and 50019 «enhanced safety».