shelly energy monitoring - forcing values | Home Assistant | Page 1

junior comet Dec 8, 2025, 4:11 AM

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I have a shelly set to monitoring 1 of the 2 hot lines going to my EVSE outside. The EVSE is also on a 240v circuit while the shelly draws its own power from a 120v circuit. The shelly assumes what its connected to is what its monitoring and those assumptiongs throw the math off. I know theres a way to force this setup to change its energy calculations to give a close enough measurement of this dual phase 240v circuit while being powered off 120v and only having a single clamp observing a single phases.

How can I tell home assistant not to trust everything its told by the shelly?

wintry lily Dec 8, 2025, 4:19 AM

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junior comet I have a shelly set to monitoring 1 of the 2 hot lines going to my EVSE outside....

why not just power the shelly from the 240v circuit?

junior comet Dec 8, 2025, 4:29 AM

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its in the breaker box, not the evse or the evse outlet

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and theres not a way I can tap into that thats code adherent

wintry lily Dec 8, 2025, 4:40 AM

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junior comet and theres not a way I can tap into that thats code adherent

whilst I don't know the specific codes of where you live...
just connect it to the same terminals in the breaker box that the cables going to the EVSE are connected to?
or you could add a box inline in-between the panel and the EVSE.
surely there is an option for doing either. or are you telling you you are not allowed to power 2 devices (one of which being a tiny load) from 1 circuit?

junior comet Dec 8, 2025, 4:52 AM

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wintry lily whilst I don't know the specific codes of where you live... just connect it to t...

I cant do that, it violates code. You cant split multiple lines off a single breaker terminal that way. Brother in law in the trades confirmed it violates code.

wintry lily Dec 8, 2025, 4:54 AM

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junior comet I cant do that, it violates code. You cant split multiple lines off a single br...

then do it in a box outside the panel?

junior comet Dec 8, 2025, 4:54 AM

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okay I'm not changing the shelly wiring.

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I asked how to alter the math in HA, not how to burn my house down.

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well, my landlords house

wintry lily Dec 8, 2025, 4:55 AM

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junior comet okay I'm not changing the shelly wiring.

then you are not installing it according to manufactures instructions so if the house does burn down your insurance may not be valid.

junior comet Dec 8, 2025, 4:57 AM

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okay, this is not going to be thrown on the 240v breaker. there isnt a clean way to do that to code. so lets move on. how do I tell HA to do its own math on this rather than trusting the shelly?

wintry lily Dec 8, 2025, 5:01 AM

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junior comet okay, this is not going to be thrown on the 240v breaker. there isnt a clean wa...

you could make helper entities that do the maths on the entities that are "wrong" and then you reference the helpers for your actual data usage.
I don't recommend using the device in this way because its not how its designed to be used.
If you truly believe that there is no way to correctly wire this device to the manufacture specifications then you should not be using it.

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if you have the space then put another 240 breaker into the panel. and put it on its own breaker?

junior comet Dec 8, 2025, 5:06 AM

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I dont. breaker is full

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its not in line so there no reason its cant do this. it has a 50A clamp. do you really think shelly intended this thing to run inline with that?

wintry lily Dec 8, 2025, 5:13 AM

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its designed to run on a single voltage/phase not a mix. using a mix is going to help with its accuracy. also its worth pointing out that most customers globally only have a single voltage to deal with.

#shelly energy monitoring - forcing values