What is a Rogowski coil?
A Rogowski coil, named after Walter Rogowski, is an electrical device for measuring alternating current (AC) or very fast current pulses. It consists of a spiral-shaped coil of wire, one end of which is usually routed back through the core to the beginning for easy connection on one side. There is no metal (iron) core. The winding density, the diameter of the coil, and the stiffness of the winding are crucial for maintaining immunity to external fields and low sensitivity to the positioning of the conductor in which the current is to be measured.
Since the voltage induced in the coil is proportional to the rate of change (derivative) of the current in the straight conductor, the output of the Rogowski coil is usually connected to an electrical (or electronic) integrator circuit to provide an output signal that is proportional to the current. Single-chip signal processors with built-in analogue to digital converters are often used for this purpose.
They are used in conditions similar to those of current transformers, but for many applications, they offer more advantages:
• Large measurement range
• High linearity
• Very useful for large or awkward conductors or in places with limited access. Thanks to the structure without a hard core, the coil can be easily produced based on the application or the available space.
• Unlike traditional current transformers, there is no risk of secondary open circuits.
• They cannot be damaged by strong overloads.
•
They are
non-intrusive. They are not powered by the main circuit that transports the current to be measured.
•
They are lightweight and can be hung on the measured conductor in some applications.
Use and selection of the right current transformer
The choice depends on the type of application you are dealing with: a machine, a retrofit on an existing switchboard, or the need for a solution that can also work well without inspection.
Master Chips has various models of current transformers in stock to combine with your network analyzers or to be connected to the energy meters managed by us.
Often, when measuring electricity consumption, the choice of current transformer is underestimated. This can lead to discomfort during installation by the operator, as well as introducing measurement errors that can affect the energy measurement of our energy meter. Please refer to our catalogue for more technical information about this item.
We recommend the version with 333mV secondary for installations remote from the measuring instrument.
RC-12 Rogowski
coils version 12mm
· Measuring range up to 100 kA.
· Calibrated to 0.5%.
· Ideal for retrofit and monitoring activities where installation space is limited.
· Easy to install, practical click connection.
· Customisation options, lengths and colours.
· Always usable with an inverter (in the instrument or externally)·
Product features
| TECHNICAL SPECIFICATIONS | |
| BRAND | PECTECH |
| Type | RC-12-900 |
| Probe diameter: | 12mm |
| TRANSDUCER LENGTH : | 900 mm (Also available on request) |
| Outer diameter of closure: | 17mm (max) |
| MAX Φ CABLE / BUS BAR: | QI-ROG-300 : 275mm |
| MATERIAL: | Transducer & Cable: Thermoplastic Rubber, Flame retardant according to UL94 V0 |
| Environmental parameters: | |
| OPERATING TEMPERATURE: | -20°C...+70°C |
| RELATIVE Humidity: | 85% max non-condensing |
| POLLUTION DEGREE : | 2 |
| Maximum Height: | 2000 m |
| ELECTRICAL DATA: | |
| MAXIMUM MEASURABLE CURRENT: | 100kA @ 50/60Hz |
| ACCURACY: | +/- 1% |
| LINEARITY: | +/- 0.2 % |
| OUTPUT SIGNAL: | 100mV/1000A @ 50Hz |
| FREQUENCY RANGE: | 20Hz... 5 KHz |
| Connection cable: | Shielded cable, 2m |
| Wire identification: | White: S1(+) / Brown; S2(-) / Bare: shield |
| Orientation: | The level of the opening piece must point in the direction of the current. |
| POSITION SENSITIVITY: | |
| MEASURED ON BUSBAR: | +/- 2% maximum with closed coil |
| EXT. VEND INFLUENCE: | +/-0.5% maximum |
| TEMPERATURE SENSITIVITY: | +/- 0.07% per °C |
| SAFETY: | |
| Operating voltage: | MAX 1000V @ 50/60Hz ( CAT III) |
| HIGH VOLTAGE TEST (Transducer & OUTPUT CABLE): | 7400 Vac @ 50/60 Hz for 1 minute |
Complete type list
Connection
Accuracy
ACCURACY CLASSES FOR CURRENT TRANSFORMERS
According to applicable standards, the error limits of the current and the error limits of the phase angle of each transformer must be within the data in the table:
