Electronic – ARD00280 Microchip Energy Reference Schematic Live and Neutral Swapped


Looking at the Microchip Energy Chip reference design

I noticed that the power is being sampled from neutral. My first reaction to this was this is backwards, that the power should be sampled from the live. however, the guide talks about the concept of a live or hot ground. what is the advantage of using a hot or live ground as the ground reference in such a design as opposed to sampling from live?

Best Answer

The current shunt of an electricity meter is in the live conductor. This means the low voltage circuit reference is the live conductor.

The voltage circuit of the meter is as you explain connected between the live and neutral circuits, with the volt drop resistor connected to the neutral circuit.

All shunt electricity meters use this principal. They are safe because the are double insulated as indicated by the \$\ {\LARGE\square}\hspace -2.2ex {^\square}\ \ \$ symbol on the faceplate.