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Mains supply energy monitoring

  • 03-04-2020 2:29pm
    #1
    Moderators Posts: 12,363 ✭✭✭✭


    Looking to get an energy monitor on my mains supply. My meter is outside, but i've an external socket right beside it to power a monitor.

    Criteria:
    • Inexpensive
    • DIY install
    • Wireless connectivity
    • API to expose metrics or some integration with Home assistant

    Ultimately I want to visualise it in Home assistant and thus Grafana, so it needs to be connected to my network in order to scrape data from it.

    I've heard of the shelly EM... is that suitable for mains? Is that suitable for Ireland or is it US specific?


«1

Comments

  • Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,531 Mod ✭✭✭✭2011


    I have a Mi Home device. This is wireless, battery powered and is DIY install. It trends my homes electrical energy usage (in watts) in realtime as well as providing instantaneous values. I can also set the unit rate but not in € only in £ (no big deal). This information is available on a PC or mobile app.


  • Moderators Posts: 12,363 ✭✭✭✭Black_Knight


    2011 wrote: »
    I have a Mi Home device. This is wireless, battery powered and is DIY install. It trends my homes electrical energy usage (in watts) in realtime as well as providing instantaneous values. I can also set the unit rate but not in € only in £ (no big deal). This information is available on a PC or mobile app.

    Thanks! That requires a hub and the monitor, yes? Seems about £110 for the hub and monitor. Unfortunately it looks like it doesn't integrate with home assistant directly, but perhaps could use their API to extract data.
    Battery powered would be handy too though.


  • Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,531 Mod ✭✭✭✭2011


    Thanks! That requires a hub and the monitor, yes? Seems about £110 for the hub and monitor. Unfortunately it looks like it doesn't integrate with home assistant directly, but perhaps could use their API to extract data.
    Battery powered would be handy too though.

    It only requires hub, not a monitor. Your smartphone or PC is your monitor.


  • Moderators Posts: 12,363 ✭✭✭✭Black_Knight


    2011 wrote: »
    It only requires hub, not a monitor. Your smartphone or PC is your monitor.

    By monitor, I meant the sensor itself. My bad.


  • Moderators Posts: 12,363 ✭✭✭✭Black_Knight


    Anyone else any experience with these types of monitors?


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  • Registered Users Posts: 170 ✭✭TobyZiegler


    Anyone else any experience with these types of monitors?

    Hey BlackKnight

    I've the efergy energy monitor for about a year and works pretty well. The app interface is crap but I was able to download another Android energy monitor app which uses their APIs from a guy called Dan Stone.

    The device I have has the standard clamps which I attached to the mains line which transmits to a receiver connected to the router. As the transmitter is battery powered it's a DIY job as you don't need to power it from the board.

    Not sure does it integrate with Home Assistant tho. If HA can integrate with ZWave devices then Aeotec do an energy monitor which could work.

    Decent list of options here https://www.smarthomeperfected.com/best-energy-monitors/ if it's any help

    There's a RasberryPi based monitor which might be worth a look as it's open source so more likely to be integratable


  • Moderators Posts: 12,363 ✭✭✭✭Black_Knight


    Thanks Toby! I'm have to check that out.


  • Registered Users Posts: 2,708 ✭✭✭kaisersose77


    I would like to do the same as I've got into using home assistant recently. For the Shelly EM how does one know which clamp to get (50A or 120A)? I just have a normal 3 bed house. Also is this something an electrician would be able to install no bother (as in there are clear instructions on how to install)? wouldn't be one for messing around with mainboard!



  • Registered Users Posts: 2,473 ✭✭✭ECO_Mental


    Just got the Shelly EM about a week ago and installed it into my main board and got it up and running with Home Assistant very easily and have it uploading to InfluxDB and then Grafana to do some fancy charts.

    You are right though it does mean messing about in your main fuse board so if you are not comfortable doing this then this is not for you. I'm not an electrician and have two feeds as I have solar PV so I had to be extra careful. Just switch off the main trip switch and the the isolator for the PV and get a phase tester to double check everything is dead. But to be honest even when I knew I had the main trip down the the board was dead I still treated it like it was still live......The trickiest part is getting power to the Shelly unit as you have to attached a live and neutral to one of the trips on the board. The CT clamps are easy just again even if you know the board is dead treat it like it live.

    I went with the 120A CT clamps as I have a house with a heat pump and I have a 16 kVA connection with a 100Amp fuse so this seamed appropriate. Once up and running and connected to Wi-Fi HA picked it up straightway and got it integrated. I have one clamp on the main ESB incomer before the PV feed as I wanted to capture any power going back to the grid. current going in the opposite direction is picked up as a negative and even the Shelly picks this as returned energy and tracks it. The sampling rate is instantaneous as far as I can see nearly every few seconds as far as I can see.

    I would recommend, I am thinking of getting another one to monitor my PV as the Solis inverter only samples every 3 minutes I think and pick up the utility room plug circuit as I have the washing machine and drier on this.


    6.1kWp south facing, South of Cork City



  • Registered Users Posts: 383 ✭✭comete


    I have a Shelly em with 120a clamp and don’t have the confidence to wire it into my fuse board myself, and don’t really use my HA for monitoring what my home is doing, mainly operating in the background to manage automations.

    I know it’s against the rules so consider this more of a heads up that I’ll be popping it on adverts.



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  • Registered Users Posts: 2,104 ✭✭✭Explosive_Cornflake


    Send me a PM or let me know when it's up, I am interested.



  • Registered Users Posts: 660 ✭✭✭bunderoon


    Hey @ECO_Mental

    I'm going to order a Shelly EM with 50A clamp.

    I have attached my CU to this thread. I'm thinking to connect the positive and neutral (once the board is dead, obviously) to the outputs of the RCBO as below. This RCBO feeds my garage radial socket circuit where nothing is being used out there - in general.


    Roughly - is this what you did? I see this it what many have done in Google images.

    Regards.



  • Registered Users Posts: 2,473 ✭✭✭ECO_Mental


    Yeah that looks ok, just make sure you connect the live and the neutral from the output of one circuit , not the live off one trip and the neutral off another. I did this by mistake and all it will do it trip instantaneously. Where the red circle is the main trip is to the left of that I presume and you will be logging this, what other circuit will you be logging? have you got solar


    ***beware I'm not an electrician so take my advice accordingly....😯

    6.1kWp south facing, South of Cork City



  • Moderators, Education Moderators, Home & Garden Moderators Posts: 8,097 Mod ✭✭✭✭Jonathan


    I can't make out the rating of that RCBO that you intend to connect it to, but you need to be aware that the RCBO/MCB is there to protect the cable and not the device. You could have a very toasty 0.75mm2 cable before a 32A RCBO/MCB trips. Have you got a 3A or 6A RCBO/MCB that you could use instead?



  • Registered Users Posts: 660 ✭✭✭bunderoon


    @ECO_Mental Yep, the main switch is the bottom left, so I'd be interested in logging the main overall usage.

    I dont have solar.

    The 2nd clamp would be for the utilty room where the washing machine and tumble dryer is used daily. Want to see how much Im using there.



  • Registered Users Posts: 660 ✭✭✭bunderoon


    @Jonathan That's a fair point. It's a 20A RCBO.

    Looking at the lighting MCBs for the house - 2nd, 3rd and 4th MCBs on middle row from left to right - they are 10A. I have no 3A or 6A for lighting. I recall the rewire of the house at the time (2012), it was 1.6mm cable used.


    For MCB then - I assume taking the live from the top of one of the 10A MCBs and then the neutral from the neutral bus bar at the bottom of the CU.

    Below , the 3rd MCB Sitting room lights.


    The Orange circle is the main feed to monitor. The 2nd last MCB on the bottom row is the Utility which I want to also monitor.





  • Registered Users Posts: 1,341 ✭✭✭Nelbert


    I had an issue with taking neutral from the bus bar with the shelly... It tripped main breaker every time.

    My light circuits were double poled (i.e. both live and neutral were at the breaker) so I tapped off one of those to power the shelly em.



  • Registered Users Posts: 660 ✭✭✭bunderoon


    @Nelbert

    Looking at my board again, the middle row, 3rd RCBO in from the left is my garage and outside garden lights. Load is about 150w .

    Anyway, that's a 10A RCBO, so I guess that is the one to go with.


    @Nelbert @Jonathan @ECO_Mental where did ye buy ye're Shellys from?



  • Registered Users Posts: 1,341 ✭✭✭Nelbert


    Got mine direct from shelly website. Make sure to cycle through the clamp options to get the best price. When I was buying a 50A and 120A clamp with it was cheaper than 2 x 50 or 120 or single clamps.

    If you've any tinkering in mind to do with smart light switches etc get one of the shelly plus modules too, worth the relatively low price to check out functionality wise (one of them works without neutral too although your wiring looks recent).



  • Registered Users Posts: 660 ✭✭✭bunderoon


    @Nelbert I ordered the 2 x 50A. It was the cheapest of the lot. Also one of the UK 3 pin smart plugs that have PM aswell. About 25 euro. I know the Tapo is half that but said I'd keep it all with one company.

    Deliver early next week.

    Now to set up HA in my docker machine.



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  • Registered Users Posts: 1,341 ✭✭✭Nelbert


    Well the good news if you are setting up HA is that once you add the Shelly's to your WiFi.... They'll be auto discovered and will be a simple add. Think their UK plug is very new so be interested to hear about it... I've a few Meross plugs that are obnoxiously wide and could do with being replaced.



  • Registered Users Posts: 1,436 ✭✭✭NewClareman


    Non-electricians working on a fuse board, let alone encouraging others to do the same, is not ok. Not only is it illegal but it could also leave you with no insurance if anything went wrong.

    I don't want to sound interfering or a busybody, but you are literally playing with fire. Our family had first hand experience of the results of poor electrical work.



  • Registered Users Posts: 1,134 ✭✭✭maxamillius


    I’d tend to agree folks, that’s a busy enough board with a mix of RCBOS, MCBs, contactors etc, very easy to leave loose connections which over time can lead to heat build up and in turn a fire…


    as per above poster, not trying to put a damper on these things as I’m a huge home automation advocate, however I am a qualified electrician and I would have to advise messing with electrics without a qualification…



  • Registered Users Posts: 660 ✭✭✭bunderoon


    I've a couple of bits that need doing elsewhere in the house for our local electrician so will get him to put in the shelly while he is here - even though I'm perfectly capable of putting it in myself.

    Post edited by bunderoon on


  • Registered Users Posts: 1,341 ✭✭✭Nelbert


    I would hope that anyone remotely uncomfortable or unsure would not touch a socket or light switch let alone add an energy monitor at the fuse board themselves.



  • Registered Users Posts: 1,134 ✭✭✭maxamillius


    Perfect if you’ve someone coming then you may aswell get them to do it, as I said, I’m not having a dig, it’s just some friendly advice from an experienced electrician that’s all!! So easy for things to go wrong, and even easier for insurance companies not to pay out when they do!!


    I like the idea of the Shelly must look into doing something similar myself, what are you hoping to achieve from the info? Is it likely that you’ll reduce run times of certain equipment etc?



  • Registered Users Posts: 660 ✭✭✭bunderoon


    No worries, fully understand.

    Our unit usage has gone up since we got the smart meter (normal 24hr tariff) in a few months ago compared to the same time of the year over the last number of years, so want to compare it versus what the shelly reads.

    I also want to see how much our dryer and washing machine is using every week. I've a feeling the dryer is on longer than that its supposed to be, be it human or mechanical 'issue'. I also like the idea of graphing the house's overall usage.



  • Registered Users Posts: 1,436 ✭✭✭NewClareman


    It's not just a question of capability, it is now illegal for anyone who is not a registered electrician to work on a mains board. I've no axe to grind here, just wising people up to the risks.

    You'd think so, but not always the case. :)



  • Registered Users Posts: 1,134 ✭✭✭maxamillius


    Interesting, are you thinking that the smart metre may not be accurate? I had smart metre installed last year also but have never really looked at the usage much…. Maybe I should?!


    although our washing machine is running constantly (2 young kids and a teenager) and I also have an electric power shower not ideal



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  • Registered Users Posts: 1,341 ✭✭✭Nelbert


    Getting sidetracked but I thought the legal bit is only regarding a rewire i.e. full install of a fuseboard?

    I've done plenty of sockets and lights but energy monitor was only time I've gone near the actual board and it was following consultation with a friend who's a sparks. Killed it outside at the meter before hand too.

    Bar energy monitors there's not much else a DIYer should even consider at a fuse board, it was the top end of my comfort zone.

    It's a quick job if you know what you're doing but a quick way to get fired across the room if you don't.



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