Jump to content

Physical Size of Current Transformers


Recommended Posts

The current transformers that come with the Shelly Pro 3EM are indeed physically a bit too large for installation in typically quite filled distribution boxes in apartments.

The ones that come with the Shelly Pro EM-50 are significantly more suitable. Does anyone know if there is a possibility to install the current transformers intended for the Shelly Pro EM-50 on the Shelly Pro 3EM? And that the calculation of current, power, and energy be accurate?

Link to comment
Share on other sites

  • Members
Posted (edited)

Both current clamps have a transmission ratio of 1:3000 and are interchangeable - with the only restriction, the 50A clamp will saturate earlier.

Another issue is the type of plug. But the plugs are both MOLEX types (micro fit 3.0), which may be easily interchanged (pins are the same).

Some details:

https://smarthome-forum.eu/thread/19721-einsatz-von-fremdwandlern-an-shellies-der-em-familie/

Edited by thgoebel
Link to comment
Share on other sites

Thank you, thgoebel, for the comprehensive answer. I believe I have all the answers I needed. I will buy an additional 50A CT for the Shelly EM; I already have two from the old EM, which broke. I just need three more MOLEX connectors, and I’ll be all set.

Link to comment
Share on other sites

  • Members
Posted (edited)

Another remark: The 50A clamp should be calibrated „on site“: Supply the Shelly pro 3EM with one phase only via terminals A to C. Connect original clamp A (120A) at IA, and 50A clamp at IB. Get a consumer with more than 500W (electric kettle or flat iron) and connect it with the same phase. Put both current clamps in correct direction at the live wire to the consumer and start calibration (A to B)…

Edited by thgoebel
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...