Resin Cast Current Transformers

Resin Cast CurrentTransformers


Rectangular current transformers in cast resin finish, available in any busbar size from 60A to 5000A with 1A or 5A secondaries.


The range is suitable for metering, protective and class X types and is particularly suited to high current and large busbars, where the rectangular style allows for easy mounting of the current transformer.

Range & Ordering Information

Rectangular resin cast CTs are available in any busbar size. Therefore please specify:

  1. Busbar Size or Busbar window required
  2. Outside / overall dimension of the CT
  3. Class & VA for metering or Protection level & VA, for example: Metering CT’s—5VA Class 0.5S
    Selection Class for metering 1, 0.5, 0.5S, 0.2 or 0.2S
    Selection Class for protection 5P10, 5P20, 10P10 or 10P20
  4. For Class X CT. specify relay type, earth fault current, secondary lead resistance (or lead length and size of wire
  5. Position of terminals and busbar clamps (short side or long side)
    Example: terminals on short side, busbar clamps on long side., or no busbar clamps.

Technical Specifications

  • Conforms to IEC185, BS 7626, BSEN 60044-1, IEC 60044-1 and IEC 61869-2.
  • Rated system voltage 0.72/3kV.
  • Ambient temperature range -5°C to +50°C.
  • Frequency range 50-60Hz (optional 400Hz).
  • Insulation level 3kV for 1 minute.
  • Continuous current, 1.2 x rated current.
  • Supplied with M6 screw terminals.

Standard Rectangular Layout

Standard Rectangular Layout

Rectangular CTs can be supplied with terminals on short side or long side of CT. The busbar mounting clamp can also be supplied on short or long side of the CT. Please specify your preference for terminal and busbar location with your enquiry.

Custom Designs

Custom Designs

As the name suggests custom designs are produced to client’s specific requirements taking into account technical issues, space limitations and product application. Our designers work closely with you to produce a solution and provide a price and delivery schedule.

On agreement the design is passed to our purpose built resin cast department where tooling is made for the CTs case and the core is wound. These two main elements are bought together and baked in our ovens to provide a strong and durable finished product complete with
connection terminals and busbar clamps where required.

Many of these custom designs are for three phase application where all three phases can be accommodated in a single cast case.

We welcome any enquiries for this service.

Cast Current Transformers

Call us now on: +44 1922 640003