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Frequently Asked Questions

  • Can I extend CT wires?
    Yes, generally the CT lead wires can be extended by 100 feet or more, but longer wires can result in increased noise or interference, which can decrease accuracy. See Current Transformer Wire Extension.
  • How can I tell if I’ve wired up the CTs incorrectly?
    See the troubleshooting section of the manual for your meter or search for troubleshooting articles on this support site.
  • Do I need shorting blocks for the CTs?
    No, our CTs have internal burden resistors and only generate 0.333 Vac, whether connected to the meter or not.
  • What is the maximum CT rated amps supported?
    This depends on the WattNode model, but most meters support 6000A or higher. See Maximum CT Rated Amps for details.
  • Can I use split-core CTs outdoors?
    Split-core current transformers are not designed for outdoor use. An operating and storage humidity range is not specified and in a high humidity environment the silicon iron core laminations used many of our CTs can rust together and can not be opened. In humid environments, spraying a rust inhibitor, such as WD40, on the exposed laminations can help to prevent rusting.
  • What is the operating temperature rating of CTs?
    The operating temperature for the ACTL-0750 series is rated −40°C to 80°C and for the ACTL-1250 series is rated −30°C to 75°C. Refer to the individual CT model datasheets for details.
  • What is the recommended absolute maximum current for CTT (solid-core) CTs?
    The UL listing allows for operation up to the following currents:
  • CTT-0750-xxx: up to 200 amps
  • CTT-1250-xxx: up to 800 amps
  • CTT-2000-xxx: up to 1,500 amps
  • CTT-3000-xxx: up to 3,000 amps
  • Do you sell current transformers with a 0 – 5 Vdc output?
    We do not. Our CTs generate 0.333 Vac at rated current and we do not sell any CTs with a DC output voltage.See CTs with DC Voltage Output.