what is current transformer of ZCT548? Zero phase current transformer with high quality

Electrical Specification

(Customized is available)

Rated Current	30A
DC Resistance at 25℃	21±3Ω
Dielectric Withstanding      Voltage(Hi-pot)	2500Vrms
Output Voltage Vo	13.2-17.8mV

1.When the current increases, the magnetic density of the core also increases proportionally. At this time, the magnetic permeability μ and the loss angle ψ also increase, the error of the transformer decreases, the ratio difference decreases, and the phase difference decreases much.

2.The error is inversely proportional to the square of the number of turns of the secondary winding. Therefore, under normal circumstances, increasing the number of turns of the secondary winding can reduce the error of the current transformer. However, with the increase of the number of turns of the secondary winding, the internal resistance of the secondary winding also gradually increases, to a certain extent, limiting the decline of the error.

The single-turn or bus-type current transformer has the simplest structure and the most material-saving. But when the primary current is small.
The error increases rapidly and cannot meet the requirements of accuracy level. So single-turn or bus-type current transformers are generally used when the primary current is greater than 300 ~ 600A; if the primary current is below 300A, a multi-turn electrical Current transformers are applied.