Upgrade from Shelly 3EM -> Shelly Pro 3EM - 120A / Reuse Current Transformers

mr-current

Hi folks,

I currently have 6 Shelly 3EM and am considering upgrading to Shelly Pro 3EM - 120A. Is it possible to re-use the existing Current Transformers or do they also have to be replaced?

Thanks for the helps in advance,

Nick

thgoebel

Welcome to the forum!

Each Shelly 3EM and pro 3EM was calibrated during the production process with its current clamps. Thus, it is recommended to use the Shelly with the appropriate clamps. Otherwise, a calibration at home is possible, but requires the removal of the (old) clamps to be calibrated. Calibration is done on the work bench.

Technically, the usage of current clamps of a Shelly 3EM with a Shelly pro 3EM is possible, but requires the modification of the plugs of the clamps. This can be easily done with an extraction tool delivered by MOLEX (MicroFit 3.0 series). But the above mentioned calibration is still an issue…