Introduction to Metering Current Transformers

Metering Current Transformers (CTs) are used with the measuring instruments, such as ammeters, voltmeters, kilowatt-hour meters, etc to:

  1.  Isolate the instruments from the power circuits,
  2.  Standardise the instruments, usually at 5 amps or 1 amp.

The scale of the instrument (according to the CT ratio), then becomes the only non-standard feature of the instrument.
If you require more information on Measuring class, please refer to our guide -> PDF

We have over 40 years of experience with manufacturing Metering Current Transformers of various specifications for customers all over the globe. Our units are manufactured to comply with different standards (IEC, ANSI, etc) and are approved by international utilities (such as DEWA).

How to choose your Metering Current Transformer

It can be difficult to pick the right CT for your application (especially if you do not have technical background).

Here are some things we will need to know before we can provide a quotation for you:

  • Ratio (eg.: 100/5A)
    • Primary (100)
    • Secondary (5)
  • Burden (eg.: 15VA)
  • Accuracy Class (0.2, 0.5, 0.5s, 1)
  • Type (ring type, plastic case, resin cast)
  • Application - indoor/outdoor
  • Limiting Dimensions - CT has to fit on a busbar or in switchgear  

If you are still unsure how to choose your CT get in touch with us on +44(0)1355 236 057 or or our live Chat!