In many industrial settings today, you may see a wide range of control panels. Inside may be one or more instrument current transformer. These applications are not the same as voltage transformers, but they play an important role in many control circuits. Here is information to help you gain a better understanding of instrument CT’s.
You could use a simple ammeter for measuring current in a circuit. Installing an ammeter to measure large amounts of current (600 amps, for example) is not feasible in many applications today. It works best when you can use an instrument current transformer which can measure from one to five amps of current continually. When wired into a circuit, the CT produces current in proportion to the conductor’s current. It can monitor the difference between one and five amps. This is more economical and practical than using a large capacity ammeter. Many CT’s provide current for circuit protecting relays.
What CT’s Do?
Most of the time, a CT lowers circuit current, and this is an important feature. Suppose you have an electric motor and you do not want it to draw more amps than it is rated for. Because a CT can monitor current, you can tell when the motor is overloaded and can do something about it before it gets damaged. In fact, the instrument current transformer can monitor and limit voltage up to the full load current. This offers valuable protection for expensive electric motors.
Choosing the Right CTs
There are several formulas you can choose, so you have the best CT’s for your needs. Since they are complicated, you should consider talking to CT experts about your control circuit needs. They have years of experience in the business and can guide you through the process of picking the best CTs for the job.