Abstract
Abstract
This paper is aiming the frequency effect to a current transformer instrument, which is used to measure current that flow in a conductor. As technology is developing, the usage of a non-linear load is higher. This will cause a problem in the power quality of an electrical system. This disturbance in power quality influencing the working frequency on an electrical system. As a current transformer is one of the equipment in the system, when the primary of a current transformer is disturbed, it could also affect the secondary side. The result shows that the frequency changing has an effect on error ratio and phase displacement on a current transformer class 0.5s, which will decrease while the frequency is increase but still within the standard limit. Frequency changing also has an effect on Security Factor on an instrument, which will increase when the frequency is increasing. So, it is important to keep frequency within the fundamental frequency.