When choosing a CT that will be best for your system consider these factors:

  • What is the outside diameter of your wire in milimeters?  Order a CT that will fit on the wire (this is the most common ordering mistake). It is ok to oversize the CT (the wire passing through can be much smaller then the CT aperture) but if it is too small then you will need to replace the CT(s).
  • What is the amperage of your electrical system? Each CT has an amperage rating. Make sure that the CT model that you choose has an amperage rating the meets or exceeds your electrical system.
  • Do you want to use solid core CTs or split core CTs?  Solid core CTs are cheaper, but require you to disconnect the primary wire, slip the CT over the wire, and then re-connect the primary wire.  Split core CTs simply clamp around the primary wire in place.