Grid-Side Load is Doubled

If you have extended the CT Clamp Cable and it is observed that the Load appears to be double what you are expecting, this can be due to the cores used to extend. Often multiple cores are paralleled to reduce resistance in the extended cable and so obtain a more accurate reading from the secondary of the CT Coil, particularly when the extension length is >10-15 metres.

When doubling or tripling cores in the CAT-6 cable the colour / white cores can be connected in parallel and the solid colour cores can be connected in parallel. But mixing solid colour cores with colour / white cores can cause interference because of the double helix winding of the cable cores. Colour and colour / white have opposite helix direction to reduce interference, but when solid colour and colour / white are connected in parallel this can be seen as two signals going into the CT Coil pins of the Inverter and therefore double the load.

NOTE - if the extension is longer than 15 metres it is recommended to use an External Meter for CT, so please refer to the relevant articles for External Meters.