CT unplugging unsafe?

I am concerned about the use of dodgy phone-plugs for CT connections…

My understanding from the IoTaWatt sales site is that one of the standard CTs supplied is an Echun ECOL09-50 . Its datasheet makes no mention of any internal protection diodes.

Thus if one were to unplug a CT from the IoTaWatt box while a significant current was flowing in the primary, thousands of volts could be produced at the plug, potentially causing breakdown of the CT’s secondary insulation, and flash-over at the phone plug.

Have I missed something here?


Yes, you have. From the IoTaWatt stuff product description.

But I don’t want to argue with you. Those UL Listed CTs are out of stock with no immediate plans to restock. You should probably look for a different energy monitor without dodgy phone-plugs. Thanks for your concern.

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I’m guessing you are the designer/seller of the IoTaWatt product, in which case I thank you for all the work you have put into the design, and I especially thank you for releasing the details under a GPL.

Sorry I missed the ‘diode-protected’ mention on your website. And yes, I will be designing/building my own version with industrial-grade connections and added protection diodes (on the transformer side), on-board voltage transformer, and an Ethernet connection instead of unreliable wi-fi (especially when such equipment is often located in a remote corner of the house, far from the W-router).