AC-AC adaptor & extension leads


I’m trying to figure out the pre-requisites needed before buying and installing an emonPi to measure household gas & electricity usage.

My meters are located outside and the consumer unit is directly behind the electricity meter on the inside wall of the house. I plan to site the emonPi next to the CU and drill through the wall so I can feed the wires for the CT Sensor/Reed Switch/Temp sensors and avoid having RF comms/ additional hardware outside.

There aren’t any mains sockets very close to the consumer unit though, so - would it work if I plugged both the AC-AC adaptor and power supply into an extension lead rather than getting an additional mains socket installed next to the consumer unit? I’ve tried searching for the info, it looks like most people have installed an additional socket nearby, but it’s not clear if this is for convenience or if it’s strictly necessary to get an accurate measurement for VRMS?

Thanks in advance


The a.c. adapter will measure the voltage it sees - obviously! Provided that your extension lead isn’t ridiculously long, or it’s got a heavy load on it as well as the Pi, or a combination of the two, then you should be OK.

Extension leads are never a good idea for a permanent installation, so I’d recommend getting a double socket installed at some stage.

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thanks for the answer :slight_smile:

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