If you’re looking at current transformers, you have two main options: split-core transformers and solid-core transformers. A contactless, split-core transformer’s claim to fame is its ability to be snapped over pre-existing wires, making them ideal for retrofitting projects and more. There is no need to screw or weld any type of bracketry, so they are easy to install. What’s more is that they can be installed inside electrical control panels, which allow you to avoid complex and often times expensive wiring. They can be installed in a live system without concern of interfering with its current operation, making it the ideal choice for engineers looking to design a power meter system.
Split core transformers are designed to remotely monitor devices that sometimes operate in inaccessible or harsh environments.
Unfortunately, the benefits that accompany split core transformers are also accompanied by a few downsides. First, split-core transformers tend to be pricier than their solid-core counterparts. Engineers also consider them to be somewhat less accurate than solid-core transformers. This is why it is important to understand the differences between split-core and solid-core transformers before making the choice as to which device to use.
Split-core current transformers are created in much the same way as solid-core transformers, but with one major difference. The core is created in two distinct pieces that are easily separated. Because the core is divided into two separate pieces, split core transformers are subject to inaccuracies due to the two pieces not always contacting uniformly. In addition, the secondary windings are not as uniformly distributed around the core as they are in solid core transformers. Because of this shortcoming, split core transformers are not the perfect choice for all applications
There are several different types of split-core transformers that can be used in different applications. For example, the FeSi split-core transformer is one of the more affordable options. However, it produces poor linearity, especially at lower currents, making it better suited for measuring high currents only where accuracy isn’t as important as getting a rough estimation of power consumption. These transformers are also bulky and heavy, meaning that they have specific physical limitations for use.
If you are looking for something more accurate, a FeNi split-core transformer does a good job. These offer better measuring performance, even under small current conditions. However, they are also a quite a bit pricier. FeNi split core transformers also struggle with linearity and take up quite a bit of space in your panel board and facility.
Ferrite split-core current transformers are another option for those looking for a split core transformer solution. Ferrite transformers have come a long way over the past few years in order to create a better, more accurate monitoring solution. The newer ferrite transformers have improved permeability and can be used in a wide range of power monitoring applications, replacing both FeSi and FeNi transformers, even with a low magnetic saturation level. They provide a cost effective alternative to FeSi and FeNi transformers.