01803 295430
sales@spwales.com
Product Code: CTR###TP
Availability: Next Day Special Order
Our range of Rogowski Coils, (frequently referred to as flexible CT’s), are an ideal alternative to traditional current transformers where fitting into tight electrical panels is required. They can only be used with meters that have a corresponding 0.333V input, (see below for our full range). They require a 12-30V DC power supply to operate which can be purchased separately.
We can supply single phase, custom length and custom range Rogowski coils upon request. Simply call or email our friendly sales team who will be happy to help.
Rogowski coils are an innovative electrical device used for measuring alternating current (AC). Unlike traditional current transformers (CTs) that rely on a magnetic core, Rogowski coils are air-cored (or non-magnetic cored) and operate on the principle of electromagnetic induction. This unique design offers several significant advantages for a wide range of current measurement applications.
A Rogowski coil consists of a helical coil of wire with the lead from one end returning through the centre of the helix to the other end, forming a loop. When an AC current passes through a conductor that is placed through the centre of this loop, it induces a voltage in the coil. This induced voltage is proportional to the rate of change of the current, not the current itself. To obtain a measurement of the actual current, the output voltage from the Rogowski coil must be electronically integrated. This integration is typically performed by a dedicated integrator unit, which then provides an output signal directly proportional to the measured current.
Wide Dynamic Range: Rogowski coils can accurately measure a very wide range of currents, from milliamps to thousands of kiloamps, without saturation. This makes them ideal for applications with highly fluctuating currents or where high peak currents need to be measured.
Excellent Linearity: Due to their air-cored design, Rogowski coils exhibit exceptional linearity across their entire measurement range, providing highly accurate readings without the non-linearities associated with magnetic core saturation.
No Magnetic Saturation: Unlike conventional current transformers, Rogowski coils do not have a magnetic core, meaning they are immune to magnetic saturation. This ensures accurate measurements even with large overcurrent’s or distorted waveforms.
Flexible and Lightweight: Most Rogowski coils are flexible and lightweight, allowing for easy installation around conductors of various shapes and sizes, even in confined spaces or on busbars that are already installed.
Safe Operation (No Open-Circuit Voltage Hazard): As they do not have a secondary winding that can be open-circuited under load (which can lead to dangerous high voltages in traditional CTs), Rogowski coils are inherently safer to operate. Low Insertion Impedance: They present a very low impedance to the circuit being measured, meaning they do not significantly affect the primary current or introduce losses.
High Bandwidth: Rogowski coils typically offer a wide frequency response, making them suitable for measuring complex waveforms, harmonics, and transient currents.
Rogowski coils are versatile and used in numerous applications, including:
Rogowski Coils have a 0.333V output as opposed to a 5A output more common with traditional current transformers. As such, they will only operate with meters that have a corresponding 0.333V input. Please see below for our full range of 0.333V input meters:
Please note, meters with a 0.333V input are not MID approved so cannot be used for billing applications.
| Measurement Range % | 5 - 120% |
| Power Frequency | 45 - 60 Hz |
| Rated Output | 0.333V |
| Supply Voltage | 12 - 30V DC |
| Power Consumption | < 30 mA |
| Accuracy | ≤ 1% |
| Operating Temperature | -25 to +70°C |
| Response Time | ≤ 1ms |
| Coil Length | 510mm |
| Lead Length | 1m |
Rogowski coils are an innovative electrical device used for measuring alternating current (AC). Unlike traditional current transformers (CTs) that rely on a magnetic core, Rogowski coils are air-cored (or non-magnetic cored) and operate on the principle of electromagnetic induction. This unique design offers several significant advantages for a wide range of current measurement applications.
A Rogowski coil consists of a helical coil of wire with the lead from one end returning through the centre of the helix to the other end, forming a loop. When an AC current passes through a conductor that is placed through the centre of this loop, it induces a voltage in the coil. This induced voltage is proportional to the rate of change of the current, not the current itself. To obtain a measurement of the actual current, the output voltage from the Rogowski coil must be electronically integrated. This integration is typically performed by a dedicated integrator unit, which then provides an output signal directly proportional to the measured current.
Wide Dynamic Range: Rogowski coils can accurately measure a very wide range of currents, from milliamps to thousands of kiloamps, without saturation. This makes them ideal for applications with highly fluctuating currents or where high peak currents need to be measured.
Excellent Linearity: Due to their air-cored design, Rogowski coils exhibit exceptional linearity across their entire measurement range, providing highly accurate readings without the non-linearities associated with magnetic core saturation.
No Magnetic Saturation: Unlike conventional current transformers, Rogowski coils do not have a magnetic core, meaning they are immune to magnetic saturation. This ensures accurate measurements even with large overcurrent’s or distorted waveforms.
Flexible and Lightweight: Most Rogowski coils are flexible and lightweight, allowing for easy installation around conductors of various shapes and sizes, even in confined spaces or on busbars that are already installed.
Safe Operation (No Open-Circuit Voltage Hazard): As they do not have a secondary winding that can be open-circuited under load (which can lead to dangerous high voltages in traditional CTs), Rogowski coils are inherently safer to operate. Low Insertion Impedance: They present a very low impedance to the circuit being measured, meaning they do not significantly affect the primary current or introduce losses.
High Bandwidth: Rogowski coils typically offer a wide frequency response, making them suitable for measuring complex waveforms, harmonics, and transient currents.
Rogowski coils are versatile and used in numerous applications, including:
Rogowski Coils have a 0.333V output as opposed to a 5A output more common with traditional current transformers. As such, they will only operate with meters that have a corresponding 0.333V input. Please see below for our full range of 0.333V input meters:
Please note, meters with a 0.333V input are not MID approved so cannot be used for billing applications.
| Measurement Range % | 5 - 120% |
| Power Frequency | 45 - 60 Hz |
| Rated Output | 0.333V |
| Supply Voltage | 12 - 30V DC |
| Power Consumption | < 30 mA |
| Accuracy | ≤ 1% |
| Operating Temperature | -25 to +70°C |
| Response Time | ≤ 1ms |
| Coil Length | 510mm |
| Lead Length | 1m |
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