Current transformers or (CT’s) are instruments that are used to transform the current from a high current into a lower current so that the power can then be used for measuring and controlling. The transformers consist of a core, a primary and a secondary winding.RS Components offer an extensive range of highly accurate CT’s in various transformer types, current ratings, CT ratio supply voltages and mounting types to suit every application. Supplied by industry-leading brands including Siemens, Murata Power Solutions LEM and of course RS PRO.
How does a current transformer work?
When an alternating current flows through the primary winding, a magnetic flux is created which then induces an alternating current in the secondary winding. This alternating current is proportional to the current in its primary. Current transformers are also known as a "step-down transformers". Once the current has been reduced it can be safely monitored and measured using an ammeter.
Types of current transformer
Toroidal Current Transformer - These transformers are shaped like a doughnut they do not contain a primary winding. Instead, the line that carries the current flowing in the network is threaded through a window or hole in the toroidal transformer. Toroidal transformers offer high efficiency with minimal excess noise and little excess leakage inductance.Wound Current Transformer The transformers primary winding is physically connected in series with the conductor that carries the measured current flowing in the circuit. The magnitude of the secondary current is dependent on the turns ratio of the transformer.Bar-type Current Transformer – This type of current transformer uses the actual cable or bus-bar of the main circuit as the primary winding, which is equivalent to a single turn. They are fully insulated from the high operating voltage of the system and are usually bolted to the current-carrying device.
Where would I use a current transformer?
CT's are used in a wide range of industrial and commercial measurement applications. Some of the most common are:Generating stationsElectrical substationsCommercial electric power distributionElectrical panels
Description:
RS Pro PCB mount current transformers encapsulated in
UL94 V0 rated plastic Storage temperature -55°C to +130°C, fully RoHS compliant. Ground fault detectionMeteringAnalog to digital circuitsSensing overload current.
Description:
Primary current range 50-150A1% accuracyOperating frequency 50/60HzTurns ratio
2500:1Rated burden resistance 33 ΩDielectric with stand voltage 4KVrmsOperating temperature range -40 to +85ºCAll materials UL94-V0.
Description:
The LEM HOYS series current transducer for electronic
measurement of current with galvanic separation between primary and secondary circuit. It has application for Drives ,converter, combiner box and inverters. Single supply +5VLow power consumptionFactory calibratedVoltage outputOvercurrent detection.
Description:
Nine predetermined control modesSingle or multiple remote controller
programming with hand-held IR transmitter (stock no. 250-0120)Direct, Reverse or Heat + Cool + Dead-band control actions12 to 24Vac/dc operation with mains option through transformer (stock nos. 250-0136 and 250-0142)IP65 ratedDimensions: H33 ...