Current Sensing Transformer (CT)

It is common knowledge that we can’t actually see electricity. Rather, we can see and measure how it works. A Current Transformer is one of the important tools used to achieve that measurement.  Current transformers provided by Bicron are designed for common commercial and industrial uses, and also for high-reliability applications that must withstand the demands of rugged environments. Our Current Transformers are best known for high accuracy and longevity.

Applications for Bicron Current Transformers include:

Computer Data Centers

Power Distribution

Energy Monitoring

Power Quality

HVAC Monitoring

Process Control Systems

Industrial Control Systems

Residential Energy Monitoring

Lighting Control

Secondary Metering

Motor Monitoring

Revenue Metering SCADA Systems

Distribution Transformer Monitoring

Solar Power Inverter Monitoring

Power Control Panels

Wind Power System Monitoring

Breaker Panels

Geothermal Power Systems

Smart Grid Monitoring

Current Sensing & Power Harvesting 3-Phase Medium Voltage CT Assemblies

Bicron’s Multi-Phase Current Transformers for medium voltage, 50Hz to 60Hz, power grid applications are self-powered through energy harvesting. Our CT design senses and powers each phase, and provides power for metering, monitoring, communications and other external electronics. Complete isolation using solid dialectrics makes our device an excellent choice for switchgear applications. Designed and built to meet customer’s unique applications. Open frame or fully potted assemblies are available.

Split-Core Current Transformers

Model Description Features
Miniature split core CT
Input 5A to 100A, Output 333m VAC standard
Busbar CT
Standard and custom sizes to 6000A, CAT IV rated
Split core CT
Five window sizes, CAT III rated
Split core CT
Millivolt AC output, 4160 VAC rated, multiple window sizes
Split or solid core CT
Weatherproof; NEMA 6P/IP68W, hinged bar
Relay protection CT
Split Core CT. Up to C800 rating, many sizes available
Relay protection CT
Solid Core CT. Up to C800 rating, many sizes available
Instrument CT
Split or solid core. 600 VAC rated
Medium voltage instrument CT
Split core, 4160VAC applications, window sizes up to 8”x8”
Flexible Rogowski coil
Input current 10A to 100KA, output 250mV, 333mV
ImagePart NumberDescriptionFeaturesDatasheet
BICRON_CT101SL_MINI_CTCT101SLMiniature Split Core CTInput 5A to 100A, Output 333m VAC standardDatasheet (PDF)
BICRON_CT104VS_CTCT104VSBusbar CTStandard and custom sizes to 6000A, CAT IV ratedDatasheet (PDF)
BICRON_CT104SMV_CTCT104SMVSplit Core CTMillivolt AC output, 4160 VAC rated, multiple window sizesDatasheet (PDF)
BICRON_CT104S_CTCT104SSplit Core CTFive window sizes, CAT III ratedDatasheet (PDF)
BICRON_CT105SS_CT-1CT105SSSplit or Solid Core CTWeatherproof; NEMA 6P/IP68W, hinged barDatasheet (PDF)
BICRON_CT105DF_CTCT105DFRelay Protection CTSplit Core CT. Up to C800 rating, many sizes availableDatasheet (PDF)
BICRON_CT105DS_CTCT105DSRelay Protection CTSolid Core CT. Up to C800 rating, many sizes availableDatasheet (PDF)
BICRON_CT105HSF_CTCT105HSFInstrument CTSplit or solid core. 600 VAC ratedDatasheet (PDF)
BICRON_CT105TMV_CTCT105TMVMedium Voltage Instrument CTSplit core, 4160VAC applications, window sizes up to 8”x8”Datasheet (PDF)
BICRON_CT121FRC_ROG_COILCT121FRCFlexible Rogowski CoilInput current 10A to 100KA, output 250mV, 333mVDatasheet (PDF)

Custom Current Transformers

Our custom Current Transformer designs are developed to meet unique customer applications.  Our extensive experience includes custom models for high voltage applications such as power distribution sensing and power harvesting. We also offer value-added assembly.  

Please use our Current Transformer Design Worksheet to describe your application requirements for a Bicron modified standard or custom designed Current Transformer.

Visit our Technical Guide for Current Transformers webpage which provides fundamentals for Current Transformer design including technical terminology.

Standard Current Transformers

Our standard Current Sensing Transformers include window sizes up to 350 square inches with current ratings up to 10,000A and current ratios from 10:1 to 6000:5. Select models are UL recognized for indoor applications.  See the selection table below for more details.

Advantages of using Bicron Standard Current Sensing Transformers:

Low cost AC current Sensing

Small size & weight

Electrically isolated output

PCB Mounting

No external power requirements

Extreme reliability

Safety recognitions

High linearity & repeatability

Simple electronic interface

Bicron’s proven Standard Current Sensing Transformer designs are great starting points for new application requirements. Our “modified standard” program permits us to substantially modify our standard electrical and mechanical specifications without incurring the cost of new product development. This allows you to quickly optimize your system at lower cost with our proven technology.

Selection of Core Materials & Models

Our preferred core material for standard current sensing transformers is Bicron’s Special Permeability (SP), with proven performance features for accuracy, linearity, low-end resolution and temperature sensitivity.  We also offer current sensing transformers made with Grain Oriented Silicon Steel (GOSS), providing good performance at a lower cost.  Bicron’s preferred SP and GOSS materials offer advantages over other typical core materials as represented in the following comparison chart:

Core material considerations:

Preferred Core Materials Advantages
Special Permeability (SP)

Improved performance over wide temp; -35°C - +80°C

Improved low level performance after exposure to DC shock

Minimal Phase Angle (Iprimary VS Isecondary) typically less than 1%

Excellent coupling of primary and secondary currents

Grain Oriented Silicon Steel (GOSS)
Provides high output voltages suitable for self-powered sensing

BICRON Current Sensing Transformers - Selection Guide

Part NumberCurrent Range (ARMS)Core MaterialTurns RatioID (in.)OD (in.)Height (in.)Datasheet
B5303*0 - 200GOSS5000:10.702.0
EX9LC2000 - 20SP2000:10.401.10
EX9LC3000 - 30GOSS1000:10.481.1
EX9LC5000 - 50SP1100:10.311.1
EX9LE1010 - 100SP1000:10.561.58
EX9LG5000 - 50GOSS1000:10.781.45
EX9LP5000 - 50GOSS1600:10.401.25
EX9PA0500 - 5SP200:10.151.11
EX9PC2000 - 20SP2000:10.401.25
EX9PC3000 - 30GOSS1000:10.481.25
EX9PC5000 - 50SP1100:10.311.25
EX9PE1010 - 100SP1000:10.561.64
EX9PG5000 - 50GOSS1000:10.781.51
EX9PP5000 - 50GOSS1600:10.401.37

Data subject to change.
*UL recognized for indoor applications.

Pinout Options

Figure 1
Figure 2
Figure 3

Bicron Current Sensing Transformers Performance Characteristics

Need More Information?

Our Sales Team is available to answer any questions that you may have. Contact them today to learn more!