Current Transformers

Current Transformers

The Current Transformer (CT) is the sensor which measures the amount of current draw from the wire it is installed on.

CTs



CT Styles


Donut vs Split-core Style

The difference between the “donut” and “split-core” style CTs is the method required for installation.

Donut CT

donut wire install 400px

Split-core CT

split-core example 400px


Installation Procedure

The installation procedure is different for “donut” and “split-core” style CTs. A depiction is shown for each (below).

Notice that the installation of the “split-core” style CT doesn’t require any wire disconnection. Although the installation is simpler and quicker that donut CTs, the split-core CTs are more expensive.


The “donut” style CT requires the branch circuit wire to be disconnected in order to thread it through the center of the CT. Although it requires more labor for installation, the donut CT is lower cost and takes less space in the panel.

donut CT installation 800px


CT installation inside the electrical panel must be done by a qualified individual or electrician. This individual must be knowledgeable and obey all safety procedures and local electrical code. See users manual for more safety information.


Donut Style CT

Micro-40 200px 

Micro-40
  • Max breaker: 40A (30A aluminum wire)
  • Max volt: 300V
  • Accuracy: typically better than 1.5%
  • Lead length: 6 1/2 ft (2 meters)
  • Certification: UL/c
 Micro-40 dimension

Micro-50
  • Max breaker: 50A
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length: 5 ft (1.5 meters)
  • Certification: UL/c

Micro-80
  • Max breaker: 80A
  • Max volt: 300V
  • Accuracy: typically better than 1.5%
  • Lead length: 5 ft (1.5 meters)
  • Certification: UL/c

Micro-100
  • Max breaker: 100A
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length: 5 ft (1.5 meters)
  • Certification: UL/c


Split-Core CT


Coming Soon (Mar 2016) SPLIT-25
  • Max breaker: 25A (15A aluminum wire)
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length:
  • Certification: UL/c

SPLIT-30
  • Max breaker: 30A (20A aluminum wire)
  • Max volt: 300V
  • Accuracy: typically better than 2%
  • Lead length:
  • Certification: UL/c

SPLIT-60
  • Max breaker: 60A
  • Max volt: 600V
  • Accuracy: 1%
  • Lead length: 6 ft (1.8 meters)
  • Certification: UL/c

SPLIT-100
  • Max breaker: 100A
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length: 5 ft (1.5 meters)
  • Certification: UL/c

SPLIT-200
  • Max breaker: 200A
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length: 9.8 ft (3 meters)
  • Certification: UL/c

SPLIT-400/600
  • Max breaker: 600A
  • Max volt: 300V
  • Accuracy: 1%
  • Lead length:
  • Certification: UL/c