• Ratings: 2.5VA to 50 VA
  • Classes: 1,3,5,10,5P10,5P15

3.6 / 7.2kV Resin-Cast Wound

This is a range of low reactance, wound primary CTs of compact design. These units are primarily for measuring overcurrent and earth leakage protection in motor control boards and switchgear at moderate fault levels or when backup fuses are employed.

The coils are completely cast in epoxy resin and can be supplied in two different sizes for each ratio. The design also has the facility for the addition of a test winding rated at 10Amps for 15 seconds.

Each unit is supplied with terminal screws and mounting brackets at no extra charge.

The maximum insulation levels are 7.2/20/60kV with a Short Time Current of 5kA for 1 second.

12kV Bar Primary Current Transformer

The primary bar is made from a high conductivity flat copper bar of cross section appropriate to the required current rating. The copper bar is contained in a synthetic resin bonded paper tube, which is filled with epoxy resin.

The ring CT itself is designed to cover BS3938, BS7626, IEC185 and BSEN 60044-1, and is manufactured according to the long established methods used over many years by ARW in supplying CTs to the Supply Authorities and Industry users. The finish is either cotton tape dipped in varnish or black PVC tape, depending on whether the CT will be used in oil or air.

The secondary current is normally 5 Amps, but other secondary currents can be supplied. Class and accuracy are typically 0.5 or 1.0 for metering and 5P10 for protection.

Since the phase centres and Busbar fixing centres in switchgear housings vary widely, ARW cannot predetermine and specify all requirements. However, our construction methods are such that we can readily and economically supply CTs to your individual specification.