Transformatoare de curent

Our extensive assortment of current transformers intended for use in different industrial applications consists of: current transformers for busbar and round conductor, wound primary current transformers, top-hat-rail transformers, and current transformers with fused terminal and din rail mounted. Our clients can always rely on us and the quality of offered products. 

What is a low voltage current transformer?

Transformer’s task is to process currents of high value and change it into a lower one.  Transformers are constructed in a special way to provide galvanic separation between initial and secondary circuits. Thanks to this function, they protect measuring devices in case of disruptions.

The most important parameters of the current transformer are:

• Rated transmission – initial AC ratio to the secondary AC, usually provided as a non-scrutinized fraction.
• AC In – effective value of initial and secondary current. Standardized initial currents’ values are 5; 10; 15; 20; 25; 30; 40; 50; 60; 75; 100 A and their multiple up to 7 500A. Standardized secondary current values are 5 A and 1 A.
• The highest working current Um – provided as the highest and securely allowed  cross-wire voltage value, which will not damage the transformer.
• Rated insulation voltage Un – standard value of the cross-wire voltage, on which is made insulation between the initial and secondary winding or grounded metal elements of the transformer.
• Preciseness class – standard number meaning the allowed device’s error. Classes are marked with the biggest allowed percentage measurement error with initial AC assigned to this preciseness class.  Preciseness classes are e.g. 0,1; 0,2; 0,5; 1; 3,5.
• Rated short-lasting heat current Ith 1-sec – is an effective value of an initial current, which should withstand the transformer, with dense secondary winding, without damage.
• Rated dynamic current Idyn – top value of initial current, which the transformer withstands with the secondary dense winding.
• Heat rated continuous AC Icth – initial current, with which the overloaded transformer can be used without exceeding a given temperature value.

Application of current transformers

Transformers are used for extending the measuring range of ammeters, which decreases costs of exploitation. Additionally, a transformer can be used as a galvanic separator of measurement and protection circuits from the main current track, which provides safety of measurement and protection installation.