Summation Current Transformer

Model SUMCT

Working Principal

Summation current transformers are used to add up secondary currents of multiple main current transformers to measure with one instrument only.

The currents are always vectorially added under consideration of the amount and phase disposal of the current so it can be used for measuring active or reactive power, energies, and total power factor of the system.

The output signal is again a standardized signal which is received by adding the input currents by the quantity of inputs and the ratio of inputs.

As mentioned above, the currents are always vectorially added, so the output is very different, and not easy to check by any clamp and multimeter. For ease of understanding, we assume the input currents have the same phase angle, only different amplitudes.

We are considering a summation current transformer with two inputs 2500/5A and one output52000/5A.

The formula is shown as below: