Can Current Transformer and Rogowski Coil cables be extended?

Current Transformer (CT) cables on the 6M & 6W series can be extended

In this article:

Extending CT Cables

Extending Rogowski Coil Cables

Extending CT Cables

CT cables can usually be extended up to 10 meters while maintaining accuracy, using:

• CAT5/6 data communication cable that conforms to a common data communication wire standard UL2464.
• Two conductors that are twisted together (to reduce induced currents from adjacent magnetic fields)
• Double insulation on the cable and join, making it easy to pull cables through boards and conduits.

For longer CT cable extensions, or noisy electrical environments, we recommend this test

1. Close the CT without a cable in the clamp
2. Connect the CT to the Auditor with a current meter in series
3. Check that the measured current is below 34mArms*

*Currents above 34mA are above the 'noise-floor' of the Auditor and contribute to Auditor kWh measurements that may cause inaccuracies. 

What cables do the 6M & 6W Current Transformers come with?

Wattwatchers Auditor 6W and 6M series use split-core CT clamps.  The cables for the CT's supplied by Wattwatchers are 1.8m long, with conductors stripped and tinned so that the multi-strand wires are easily inserted into the CT connector.

Wattwatchers CT cables:

• Conform to UL2464 and are double-insulated.
• Have two conductors that are twisted together to reduce induced currents from adjacent magnetic fields.
• Have pink (+ve) and white (-ve) insulation over the two wires
• Are flexible and white, with an outside diameter of 3.6 mm

Extending Rogowski Coil Cables

Rogowski Coil cables can also be extended up to 10 meters following the same approach above.

• 2 x 22 AWG with shield wire.