Choosing a Core Transformer: Factors to Consider

Most industrial processes that rely on electricity require the use of power meters. These devices allow operators to measure just how much electric current is being utilized and thereby monitor changes or fluctuations that may affect productivity. Power meters and other electrical measuring instruments come with a small but extremely vital current transformer (CT), which reduces the level of electric current that passes through the measuring instrument.

Since transmission lines support different levels of current and voltage, there is no standard CT for any type of circuit. Therefore, when choosing a CT for a particular circuit, several factors have to be considered. For instance, the voltage of the circuit must be bearable for the measuring instrument. The voltage can be measured by touching the leads of a multimeter on any point on the circuit.

Another factor to consider is the rated load or the total distribution loss between the CT and the measuring instrument. The longer the wire of the secondary winding, the greater the current loss. This, in turn, affects the result of the measurement. Consequently, all losses have to be factored in to produce an accurate measurement.

Finally, it is more advisable to choose a CT that has a built-in voltage restraint. Among other things, CTs that lack this component are at risk of catching fire when the secondary circuit is open, given the high voltages flowing from the primary circuit to the secondary circuit.