The FCT series flexible rogowski coil current sensor can monitor AC line current in circuits up to 600 Vac and nominal currents up to 6000 Amps. It is designed to use where regular solid or split core current sensors cannot fit, and ideal for power quality monitoring such as harmonics. Advantage including high accuracy, wide measurement and frequency range, and no additional integrator and power supply is needed. They can be opened and are flexible for ease of installation around bus bars and multiple conductors.
They are intended for field installation within distribution and control equipment such as panel-boards, switch-boards and industrial control equipment to measure the current on branch circuits and feeders. The FCT series may be used with electric energy meters, like the WattNode meters, or for other current measuring purposes.
FCTs are different in a few key ways from standard CTs. They do not contain a ferromagnetic core, so they will not saturate, they have excellent linearity, and they have very low phase angle errors. Because they lack a core, it is possible to make them flexible and lightweight. Furthermore, the coil output signal is low voltage (less than one volt AC) and low current (micro-amps or less), so they are safer than ratio CTs. FCTs generally require an integrating conditioning circuit, since the output of the coil is the derivative of the actual current. FCTs are very dependent on the uniformity of the windings in sense coil, making them more sensitive to the position of the conductor(s) being measured in the opening and more sensitive to the magnetic fields from external conductors.