If you check out industrial settings, and look at wiring diagrams, ladder diagrams, or look inside control panels, you may see a wide range of transformers. Some are important for controlling voltages while others are used for changing the electrical current. Here is a closer look at the difference between the potential and current transformer.
Voltage and Current
To understand current transformers, it is important to understand the differences between voltage and current. To best explain, think of a garden hose connected to a water faucet with water flowing through the hose. Electricity flows through a conductor much like water flows through a hose. Water pressure is similar to electric voltage. Water volume is similar to electric current. Voltage is the pressure at which electrons flow through a medium, while current is the amount of electricity which flows at a given time.
Potential Transformers
A potential (voltage) transformer uses two coils of wire close together. When you induce electricity into one set of coils (primary), it acts on the other coil (secondary) in proportion to the difference in coil windings. These devices can either lower or raise the voltage.
Current Transformer
Unlike potential transformers which affect voltage, a CT affects the electrical current flowing. They are commonly used to monitor current in sensitive circuits. For example, components in electronic or control circuits could easily overheat when too much current flows through them.
How the Current Transformer Works
Potential transformers use primary and secondary coils, and one always has more windings than the other. Yet, both coils usually have a significant amount of windings. A Typical CT configuration may have only one coil or a solid bar for the primary side and a lot of coils in the secondary side. Primary current is controlled by an outside load, not the secondary coil (as with potential or voltage transformers).
