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Heating and cooling: I boost keeps sending power to the grid

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  1.  
    • CommentAuthorjhsigma
    • CommentTimeMar 2nd 2023
     
    I have just had installed a solar system with an I boost and car charger the intention was that initially the solar power would go into to the thermal store ,but any power generated goes partly to the grid even if the thermal store needs more does anyone know how to stop sending power to the grid when its needed in the house ? Thanks
    •  
      CommentAuthordjh
    • CommentTimeMar 2nd 2023
     
    What do you mean when you say 'partly'? All diverters 'leak' a bit of power back to the grid, just to allow for component tolerances etc and make sure that they never consume power from the grid. So it's normal for me to see RED on my electricity meter for example even when the diverter is operating. But if I look at th epower that's being exported, it is very low and the vast majority of the power is going into my thermal store. So how are you measuring how much power is being exported, and how much is it?

    If it is a significant amount, then either it's a faulty unit or there's some other factor you haven't yet told us.
    • CommentAuthorjhsigma
    • CommentTimeMar 2nd 2023
     
    Thanks for the info djh ,your correct it is low power .01kw (and intermittent )going back to the grid Im looking at the myenrgi app on my phone and the screen on the Zappi . The original intention was to dump into the thermal store until it reached 80 deg then the balance to the car (74kw battery )and then if anything left back to the grid ,but when I plug the car in it all goes to the car
    Could that be a setting on the Zappi do you think ?
    • CommentAuthorrevor
    • CommentTimeMar 2nd 2023
     
    It may be conflict between the I boost and Zappi. My energy make a number of items that work as a suite to get things to work you may need a my energy Eddi diverter. I cant say I am that knowledgeable about this but have looked into the Zappi for when I get BEV. Contact support at My energy they gave me a lot of info on use of Zappi in conjunction of my solar system that has a battery. They were v helpful.
  5.  
    You can set the export threshold on the i boost , its in the instructions.
    'STORAGE OFFSETT'
    default is 100W, you can increase that to 500W in 50W increments. its probably set at that to avoid accidental import for the element or perhaps its just not considered viable to have the unit constantly switching for less.
    As an additional load comes on and off it appear on the meters the iboost builds and drops off slowly to available power rather than switching in and out instantly. Its constantly variable output unless over 3kW.
    Zappi probably has and export threshold as well.
    Set them to suit your desired result.
    Also make sure the CT clamps are at least 10cm apart
    •  
      CommentAuthordjh
    • CommentTimeMar 5th 2023
     
    Posted By: jhsigmaThe original intention was to dump into the thermal store until it reached 80 deg then the balance to the car (74kw battery )and then if anything left back to the grid ,but when I plug the car in it all goes to the car
    I don't know anything about the particular devices in question and any possible clever interlinks they might have, but I think in general it matters which way round the devices are connected to the incoming mains. i.e. the order of connection along the wire. IIRC the furthest from the meter will get first dabs on any available power and the second one closer to the meter and grid will only divert anything left over after the furthest has had its fill. I'm sure somebody will correct me if I've got it the wrong way around!
    • CommentAuthorCWatters
    • CommentTimeMar 15th 2023 edited
     
    0.01kW is just 10W. I don't know what the typical leakage back to the grid should be but that seems pretty low to me.

    I wonder what the tolerance is on the meter?
    • CommentAuthorGareth J
    • CommentTimeMar 17th 2023 edited
     
    I would expect to accept a bit of leakage back to the grid, especially with a lower export threshold. I wasn't aware you could alter the export threshold on the iboost bit of you can, as mentioned above, and 10W bothers you, try upping the threshold. But you'll save less extra than you missed before, if that makes sense.

    I can't see how the order of the CT clamps on the cable makes any odds, preference is determined by export threshold. The distance between them can make a difference though, had to space two of mine ~20cm apart to stop them "fighting" each other.
    •  
      CommentAuthordjh
    • CommentTimeMar 17th 2023
     
    Posted By: Gareth JI can't see how the order of the CT clamps on the cable makes any odds
    Because the furthest from the meter sees the whole generation, whilst the one nearer the meter sees the generation net of whatever the first has diverted. (Assuming the generation itself is further away from the meter than either CT.
    • CommentAuthorGareth J
    • CommentTimeMar 17th 2023 edited
     
    Posted By: djh
    Posted By: Gareth JI can't see how the order of the CT clamps on the cable makes any odds
    Because the furthest from the meter sees the whole generation, whilst the one nearer the meter sees the generation net of whatever the first has diverted. (Assuming the generation itself is further away from the meter than either CT.


    Not unless there are wiring (and therefore load) spurs between the two CTs. Current in at one end of a wire is current out at the other, less losses. Unless something is very wrong. Both CTs on a continuous wire will measure the same current.

    The logic seems obvious to me but I am happy to physically test it with the pair of CTs I have to see which one "wins" if you like. When I installed it, I paid zero attention to which one was where. Just that they were far enough apart and the right way around.
    •  
      CommentAuthordjh
    • CommentTimeMar 18th 2023
     
    Sorry, I assume that the CTs are connected adjacent to the diverted loads, so exactly the diverted load is what is between the CTs.
    • CommentAuthorGareth J
    • CommentTimeMar 18th 2023
     
    Posted By: djhSorry, I assume that the CTs are connected adjacent to the diverted loads, so exactly the diverted load is what is between the CTs.


    Ah, ok. Yes can organise things physically logically that way but I think it's more common to put all CTs on the meter tails and let the differing export thresholds organise priority.
    •  
      CommentAuthordjh
    • CommentTimeMar 18th 2023
     
    Given that my meter tails are about 30 m from my DHW diverter I doubt I would do that.
    • CommentAuthorGareth J
    • CommentTimeMar 18th 2023
     
    Posted By: djhGiven that my meter tails are about 30 m from my DHW diverter I doubt I would do that.


    If your solar is wired into the meter Henley blocks, as many (most?) will be, you might not have a lot of options! Plenty of diverter widgets have wireless sender's now. I've got one leap frogging about 35m. In extremis, I have even run a length of swa back to a remote phase where generation inverters are, to feed, via a hard wired diverter, into an indoor immersion/storage heater. But I get that that's going to be unusual.
    •  
      CommentAuthordjh
    • CommentTimeMar 18th 2023 edited
     
    Posted By: Gareth J
    Posted By: djhGiven that my meter tails are about 30 m from my DHW diverter I doubt I would do that.
    If your solar is wired into the meter Henley blocks, as many (most?) will be, you might not have a lot of options! Plenty of diverter widgets have wireless sender's now. I've got one leap frogging about 35m. In extremis, I have even run a length of swa back to a remote phase where generation inverters are, to feed, via a hard wired diverter, into an indoor immersion/storage heater. But I get that that's going to be unusual.
    My meter is about 30 m from my DHW diverter and its associated CT. My diverter is near the solar connection to my mains system, at the main CUs where it is attached. i.e. the diverter and CT are in one place, the meter is in another. As is my EV charger, but that is currently dumb. Why would solar be wired into an [import] meter rather than through a CU?
    • CommentAuthorGareth J
    • CommentTimeMar 18th 2023
     
    Posted By: djh. Why would solar be wired into an [import] meter rather than through a CU?


    That's how my MCS array was done. Has it's own breaker and direct supply from Henley blocks. Same with our MCS WT. I can't tell you why or of it's mandatory/common/uncommon though. The CU is right next to them though so logistically, just as easy. I can imagine that, with yours being some distance away it made sense to wire to the CU. Indeed I have done that for my own, non MCS system.

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