I recently installed the new Homey Energy Dongle. Nice device, and gives me good additional insight in my energy usage.
I also have solar panels on my house, but unfortunately they stop working regularly on sunny days, as the solar energy converter goes into safety mode to protect it from too high voltage on the main power grid (a problem often heard of in certain parts of the Netherlands as the energy net is overloaded on these days).
A possible solution could be to connect my solar panels to another phase. However, success is not guaranteed as the voltage on the other two phases could be problematic (= > 10% too high) too.
I was eager to use the Energy Dongle to measure the actual voltage on all three phases, but unfortunately, the dongle does not collect the voltage information. It does however provide the current and the current power. So simple math would give me the voltage. However, the current is given in units of 1 amperes, so very coarse. Which effectively means I have no accurate reading of the 3 phase voltages.
Does anyone have an idea how I can solve this, and get the accurate measurement of the 3 phase voltages such that I can determine whether there is indeed one phase less loaded (or not) before I have a costly change in my metering box?
Thanks JohanP! You mean a smart powerplug with energy measurement capability? I don’t have such a plug, but indeed that could be a good idea. And I was considering buying one anyway.
If you happen to have a recommendation what is a great plug for this, please let me know. (I have Homey Cloud Premium, no Homey Pro (yet)).
Found one from Shelly on WiFi with energy metering, and for 3680 W as I want to use it for a washing machine. The product info (in Dutch) says it measures current. But does it also measure and give a direct read out of the voltage (as I want to prevent I end up with an inaccurate indirect measurement as now with the Energy Dongle)?
The dongle itself doesn’t measure anything, it is the interface to the P1 Data from the DSMR Smart Meter that measures and reports it. So Don’t blame the Homey Energy Dongle, Let your Grid operator replace the DSMR Smart Meter. If that Isn’t possible, don’t trust any other P1 interface and install that costly own Power/Voltage/Current meter.
Indeed, I also noticed a post by another user that does show voltage information, as @Peter_Kawa rightfully pointed out in his post above. So it leads me to believe that it is rather the smart meter, exactly as you said.
I can ask the grid operator to give me a better smart meter alternative, but I doubt if that is feasible. There is no incentive for them to do so in an already overburdened grid.
But rather than buying and installing a costly own power/voltage/current meter, just for nothing more than diagnosing whether or not one of the other two voltages is not/less overloaded to keep my solar panel converter from going into overload protection mode, I thought about a simpler method:
use a good old multimeter with probes, and stick these in a few wall outlets related to the other phases a couple of times a day on a sunny day and measure how voltages behave and how close they are to the converter safety levels (253 V). This is a cheap and direct way, and saves a lot of cost.
It may be usefull to post what type of smart meter you have, also, there’s a topic on this forum about compatible smart meters, maybe that can be of help.
I’d first send the grid operator a message about missing voltage measurements on the P1 port. It’s a pretty important part of all the measurements.
It might be just a setting, or firmware or such. They should be able to check (& fix) all of that remotely.
I get why you want to use the phase with least voltage peaks, but I don’t think it’s a permanent state. I.e. next month an other phase can just have the least voltage peaks.
Here you see my Solis limit the output on grid overvoltages:
(it’s 5 minute data, the dips are way more narrow in reality)
Back to the original problem, why not hafe a 3 phase relais installed ? If I’m.informed correctly it will simply switch off one of the phases and continue to work on thd others…
Good suggestion! The meter is a Kaifa MA304C. I could not find any posts on this type of meter on this forum, but if anyone has experience with this type, I am eager to know.
Also, I looked up the info that Liander (the grid operator) publishes about this meter. It does not really provide a technical specification, but from the information they publish, indeed it looks like the P1 port gives current and power, but not voltage. So that would explain the situation I am running into when attempting to get voltage readings via the dongle.
Further to the reply of @peter_kawa I will give Liander a call on Monday to ask them about it and see if they can do something (either by a firmware update or otherwise) to help me measure the 3 fase voltages.
@peter_kawa - I am not sure I understand your remark that the phase which has the highest voltage peaks might change over time. Do you mean changes at the grid side, so outside my house? That I would understand, and is a good point. It would mean that even when I find a less loaded phase now, and have a professional rewire my solar panels in my meter to that less loaded phase, in some time from now I may end up with the same problem again. Correct?
On a separate note - my converter can not limit the output like your Solis seems to be able to do. It is a 1-phase converter (SB 3600TL-21) and when the voltage becomes too high, it simply shuts off, rather than limiting the output.
This is a bit beyond my expertise @JohanP . My understanding is that in any case this would be a change in the meter cupboard by a professional and not something I can do myself. If this would be possible, it might help to overcome the problem that @peter_kawa mentioned that the highest voltage peaks may vary over the 3 phases over time.
P1 just gives the available messages from the meter., so you have just a 1 fase meter. With a smart 230 volt plug you measure just the voltage at that spot in your house not at the entrypoimt in your house. The homey dongle works perfect. For one and 3 fases. If you have more than 12 panels you need thee fases for the power.
