2 minutes reading time (302 words)

CT Circuits – The Importance of Grounding the Secondary Side

Midwest Current Transformer is one of the most trusted sources for current transformers in the industry. We offer a wide range of transformers and can create custom transformers to meet the most difficult specs. When you wire a current transformer, it is very important to make sure the secondary side is grounded and here are some reasons why.

How CTs Work

To better understand CT circuits, it is important to know the primary side of the transformer creates a magnetic field when current flows through it. This causes current to flow from the secondary side. The primary side is the current source for the circuit. In order to keep current flowing through the secondary, the primary (source) produces current in proportion to the secondary side. In fact, it produces enough to keep the current flowing.

Because the primary depends on the secondary, when the secondary connection gets grounded or shorted, then it takes little voltage for the primary to operate. If the secondary winding has resistance in it, then it tries to create a magnetic field opposite of the primary.

If the secondary is not connected to a load, then it tries to maintain the counter magnetic field, and voltage levels may skyrocket. Levels can get so high, the air around the CT may start to break down and lose its insulating properties. This is why you should always make sure the secondary side of the CT is shorted.

Help with Your CT Applications

Understanding how current transformers work and why they need special considerations when wiring is important. However, there are many things to consider when you replace or upgrade your transformers. Midwest Current Transformer is there to help you make the right decisions for your business. Call us toll-free today at 1-800-893-4047 to learn more about our products and services.

Things to Know About Current Transformers
Metering Vs. Protective Current Transformers