3-phase: to much consumption, wrong installation?

Hi there,

I installed a flukso at my parents house that has a 3-phase electric power system (Belgium). I don't now anything on the topic so a friend helped me to install the 3 clamps on the wires. However, I'm not sure that it measures the power correctly as the power displayed seems way too high (they have a heat pump but still...). There is also a PV installation installed on the pulse port that seems to display the correct values.

Here is the installation with the clamps attached (there is not enough space to put all 3 clamps on the top, so one is above and two are below):

And here is a screenshot of the power output:

In flukso settings, I 've set number of phase to 3, voltage to 230 and current to 50.

Does someone knows what is wrong there?


gebhardm's picture

From the pictures first it looks O.K., as the main breaker bottom three blue cables seem clamped. But what irritates me, is the circuit printed on the breaker itself that indicates a ground test option between the two left input terminals; so the most left seems to be a return (ground, star connect, don't know).

Let's describe what I see: There are four mains cables running into the main breaker: black, black, brown, and blue.
From the circuit diagram on the breaker there is a ground test between the first two terminals, so the two black cables (what I suppose to be the 30mA safety breaking of one phase against ground or star connect).
The clamps, to what I can see, are attached to black (top, second terminal), black (bottom, first terninal) and brown (bottom, third terminal) - well, then I suppose, by the bottom black clamp this is put into the return path of the circuit, so summing the complete power consumption (but this is what I guess as I do not know why there are four cables in the first place) - I would have supposed to put the clamps on second black, brown and blue according to what I see on the breaker switch...
So - to what you describe, there indeed one clamp seems to detect the sum of all - I would say, the first one...
Facit: Proposal - put the clamp from the bottom first black to the last blue and see if the sum disappears (or ask an electrician of your trust what the black/black/brown/blue cables are)
Wondering, Markus - in our house there are three mains lines, black, brown and blue...

fusionpower's picture

Not sure if this would work but setting all three as single phase so you get a chart line for each. Then you could see which clamp was getting incorrectly high values. You may even see an single phase appliance's pattern in one clamp and see it on the clamp that is seeing multiple phases. And once you identify the incorrect clamp, if any, you could them move it to the wire that is currently unclamped.
I don't have 3 phase power so this is just a guess.

leroyb's picture

Thanks for you answers.

I changed the flukso settings to get chart line for each (setting 130V per phase, is it right?). Here is the output with the new setup:

The blue line (consumption1) corresponds to the left black wire.
The red line (consumption2) corresponds to the second black wire.
The green line (consumption3) corresponds to the Brown wire.

The green line seems to be more realistic.

What do you think?


bazzle's picture

Can you work out from your Meter what the usage is over a set time to compare to graph?

gebhardm's picture

From the graph at least "consumption 1" does not seem to be a sum signal; note: Europe has a continental single phase voltage of 230V (see http://www.sensorcentral.com/worldsupport/standards12.php)
Well, as consumption 2 (which I would regard as "correctly attached") has peaks in the direction of 5000 watts (like consumption 1 also has) the question goes back to you what kind of electricity users you have in your home: is there an electrical heating? Something that you know to pull a lot of power? Feasible or not is a matter of the devices you have; I see peaks in this direction in our home only if, for example, the dish washer is operative as we have not electrical heating...
So, from the graph, this might all be reasonable and corresponding to the standard's description all well-connected - depending on what is operative in your home.
Therefore: What kind of devices are active during peaks? What is their specified power comsumption?
Here the FLM works as incident provider, the Dr. Watson, and it is on you, Mr. Holmes, at first to check plausibility...
Regards, Markus (from the south-west of Germany)

leroyb's picture


All I can say is that there is a heat pump in the house, that could explain those peaks.


on3ptz's picture

Did you split the electrical system into consumption and production ?

one of your clamps is before the eartleak switch, and that can never be correct if you have solar ...

gebhardm's picture

@on3ptz - the earthleak breaker is just a switch - when closed hopefully a zero ohm conjunction; so there is no difference in putting a clamp before or after it from the physical point-of-view... it is different of course with putting a clamp before or after a meter. See also the discussion in https://www.flukso.net/content/seperating-household-consumption-and-gene...

fusionpower's picture

Looking at the chart with the configuration changed to 3 separate single phases rather than the combined 3 phase i couldn't understand the why the combined part to the chart would not be the sum of the three single phases. According to the colour chart Gebhardm supplied the clamps are on the correct cables, the incoming blue wire should be the Neutral and the two black wires and the brown wire the three phase inputs.
Then i re-read your comments and you say you set the single phases as 130v but the three phase was set as 230v.
I suspect either the three phase config should be 130v or the single phases 230V.
You will need to confirm that with someone who knows.
I suspect you have some sort of large load that is using two of the phases, electrical heating, pool heater, under floor heating etc. This is why 2 phases have the high consumption and the third phase much less by comparison.
If the three phase setup should be 130v then that is going to reduce the combined consumption figure significantly, almost halve it.
Then you just need to check the combined consumption against what your consumption meter is showing.

Arnold's picture

As I can see in the pictures, you have a 3x230V system instead of a 3x400+N system. This means you measure 230V between 2 phases and 130V between phase and neutral but my guess is that the neutral (bleu incoming line) is not even connected upstream. The Neutral is not provided by the E-company because you can't use this 130V. (It’s just there because it comes from a standard XVB cable). I this case I think you should use 130V in the flukso sensor settings.

leroyb's picture

Hi All,

I finally managed to get the right consumption by using 130V in the flukso sensor settings as suggested by Arnold.

Thanks all for the support.