If the current waveform is not clear, you need a big load (your electric kettle) and move it around to different sockets until the wave you are looking at gets bigger. (I was using about 20 A on a 100 A input. That is certainly big enough to see the phase relationship clearly enough. But 10 A (10% of full load) might have been not enough.)
There is no such thing as absolute phase. Everything is relative. Your “brown” phase might or might not be the same as a neighbour’s, and it might be the same as, or shifted 60°, 120°, 180°, 240° or 300° from someone in the next town. (You get a 60° shift going through a delta-star transformer.)
So as far as the emonTx is concerned, the sketch regards the phase that the a.c. adapter is on as phase 1, then the other two must follow in sequence on inputs 2 & 3.
Good evening! This is my results. I’m having trouble interpreting these…can there be some fault related to me using the same GND for all three CT’s ? Some bias from heat pump (which operates at 3-phase) running while doing these tests ? Refrigerators ? Are the CTs reversed ?!
Input 1:
cycleCount 254, samplesRecorded 226
| v c |
| .vc |
| c. v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c .v |
| c v. |
| c . |
| v c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v. c |
| v c |
| .c |
Input 2:
cycleCount 2204, samplesRecorded 227
| vc |
| . c |
| . c |
| . vc |
| . c |
| . vc |
| . c |
| . c |
| . c |
| . vc |
| . c |
| . c |
| . cv |
| . cv |
| . c |
| . c |
| . cv |
| . cv |
| . cv |
| cv. |
| c . |
| cv . |
| c . |
| c . |
| cv . |
| c . |
| c . |
| cv . |
| c . |
| cv . |
| c . |
| vc . |
| vc . |
| c . |
| c . |
| c . |
| c . |
| vc . |
| vc |
Input 3:
cycleCount 254, samplesRecorded 227
| cv. |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c. v |
| c v |
| c v |
| c v |
| v.c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v .c |
| v c |
| v c. |
| v c. |
| vc . |
There is something seriously wrong. My first concern is the voltage trace appears to have a different magnitude in each case, and it is horribly distorted in the case of Input 1. We do not expect it to be a perfect sine wave, because the a.c. adapter adds a little distortion, and the 80-columns wide printout is a limitation also. But it should not be that shape. The voltage curve for Input 2 looks believable, but you should see exactly the same voltage curve in each case.
I need to find out why the voltage is so different in each case. You did not move the a.c. adapter, did you? How and where is it connected?
Connected like this and then into a wall socket approx. 1 meter away.
EDIT: I am using this AC:AC adaptor as power source for the emonTx to, if it changes something. And no, I did not move the AC:AC adaptor. I just changed the sketch on line 19. Solely line 19, changed it between 1-2 and 3 and ran the serial monitor. Should I’ve changed line 18 to ? The one that says “voltageSensorPin” ? Other than that i just ran around my house with a waffle-iron and a toaster
No, what you did appears to be correct. Now I’m completely puzzled.
It looks as if the voltage changed completely - both the amplitude and the shape of the wave - according to where you plugged in the appliances. And that should not happen.
There are two possibilities: either that is really what is happening, or the emonTx is not measuring correctly.
I need to draw exactly what I think you have, and then try to work out what might be wrong. I will be away all day tomorrow, so it might be 2 or 3 days before I am back to this.
Ok, just to test things, I removed the extra prolonging cable (don’t know the exact name in english) and connected the emonTx’s AC:AC adapter directly to the wall socket and surprisingly my readings on all three phases went from -3000 to 4-500w positive and almost corresponding to my energy meter outside showing around 600w…!
Don’t know if this is random and maybe had to do with my heat pump stopping at the same moment or something like that but it sure changed! Well see during the night and coming day.
The English is “Extension Cable”. And there must be something wrong with it - maybe a bad connection somewhere? That would explain the 3 different voltage graphs - something moved a small amount (you walked past?) and changed it from bad to good and back to bad again? It would not be the first time I have had a huge problem with something like that - it once took me 2 YEARS to find a bad joint.
As far as I could see during last night and today during the day it seemed to work ok.
This evening, by looking at my energy meter outside it tells me the total active load is 3800w and emonCMS gives me around 4500w. Is this some error that can be calibrated or something I have to live with ?
I did have to move my emonTx now to be able to run without extension cable. When hooking it all up again i put the AC:AC adaptor in to my wall socket in the other direction and directly had negative readings. Is it important at what direction the AC:AC adapter is plugged in to the wall ? By changing it again back to how it was before the move I had normal positive readings again.
Finally I took another round of readings with Robin Emley’s test sketches again. Do they look more normal ?!
(both heat pump and a clothing-dryer was running).
Input 1:
cycleCount 254, samplesRecorded 227
| v. c |
| .v c |
| . v c |
| . c |
| .c v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c .v |
| c v. |
| c v . |
| c v . |
| v c . |
| v c. |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v c |
| . v c |
| . v c |
| . cv |
Input 2:
cycleCount 254, samplesRecorded 227
| vc |
| . vc |
| . c |
| . c |
| . vc |
| . vc |
| . vc |
| . c |
| . c |
| . c |
| . c |
| . c |
| . cv |
| . c |
| . cv |
| . c |
| . c |
| . cv |
| .cv |
| cv . |
| cv . |
| cv . |
| cv . |
| cv . |
| c . |
| c . |
| c . |
| c . |
| c . |
| vc . |
| c . |
| c . |
| c . |
| vc . |
| vc . |
| vc . |
| vc . |
| c . |
| .vc |
Input 3:
cycleCount 254, samplesRecorded 227
| c v. |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c. v |
| c v |
| .c v |
| . c v |
| . vc |
| v. c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v .c |
| v c |
| v c |
| v c. |
| v c . |
| v c . |
| cv . |
I cannot think of a good reason why the voltage wave should be different when you are looking at the current in each phase, except that the wiring cannot be what it should be. This is what you should have for the c.t’s:
The dashed line inside the emonTx represents the ‘earthy’ 1.65 V d.c. bias for the input which, if you use a common return wire for the c.t’s, must be that common connection.
Can you check that there is no other connection to either any of the c.t. wiring or the a.c. adapter wiring?
I took the emonTx outside to my meter cabinet just now. Hooked up the CT’s one by one without common return wire. The AC:AC adapter had to be attached to a extension cable about 10 meters long (did not find a shorter one).
The inputs from the CT’s are hooked up L1-input 1, L2-input 2, L3-input 3.
Got these results. Can the AC:AC adapter be faulty ? The CT’s not working ? Am I using the sketch in the wrong way ? What might be the next step ?
EDIT: Did I do something wrong with the burden resistors ?
INPUT 1:
cycleCount 904, samplesRecorded 71
| c v |
| cv |
| v c |
| v c |
| v c |
| v. c |
| v. c |
| .v c |
| . v c |
| . v c |
| .v c |
| .v c |
| v c |
| .v c |
| .v c |
| . v c |
| v c |
| v. c |
| v. c |
| v . c |
| c. |
| c v. |
| c v . |
| c v. |
| c v |
| c v. |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v. |
minVoltage 471, maxVoltage 549, minCurrent 249, maxCurrent 775
INPUT 2:
cycleCount 254, samplesRecorded 227
| c |
| . vc |
| . c |
| . c |
| . cv |
| . c |
| . vc |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . cv |
| . cv |
| . c |
| . cv |
| . c |
| .cv |
| cv. |
| cv . |
| c . |
| c . |
| vc . |
| c . |
| c . |
| c . |
| c . |
| cv . |
| vc . |
| c . |
| vc . |
| vc . |
| c . |
| c . |
| vc . |
| c . |
| vc . |
| vc |
| . vc |
| . c |
| . c |
| . c |
| . vc |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . c |
| . cv |
| . c |
| .cv |
minVoltage 310, maxVoltage 712, minCurrent 307, maxCurrent 715
INPUT 3:
cycleCount 704, samplesRecorded 115
| c v |
| c v . |
| v c . |
| v .c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v. c |
| v c |
| v c |
| .v c |
| .v c |
| .v c |
| . v c |
| . v c |
| v c |
| .v c |
| .c v |
| c . v |
| c . v |
| c . v |
| c .v |
| c .v |
| c .v |
| c .v |
| c . v |
| c v |
| c v. |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v . |
| c v. |
| c v . |
| v c . |
minVoltage 460, maxVoltage 561, minCurrent 329, maxCurrent 695
Are we sure the blue cables from CT is infact return/GND ? (that was how it was made in my house from the beginning).
I have checked once again. Sleeve of the 3.5mm connector is connected to blue cable from CT, Tip is connected to “signal” cable (brown, they are all three brown) from the CT.
The burden resistors should not affect what you see on the voltage channel. You could have got that wrong, but it is difficult to see how. And the current waves look believable.
To check, can you post a clear picture of the emonTx circuit board showing your new burden resistors?
It is the different shape of the voltage that is what is worrying me. You are not changing the voltage input, therefore you should see exactly the same shape printed with the letter ‘V’ each time. You want to see something very like the V’s in my picture in post 39 (but for 3 complete cycles of course, and the amplitude will be a little less).
What do you record for the voltage with NO c.t’s plugged in - only the a.c. adapter?
That is just perfect, no problem there - I was typing when you posted the picture, so I did not see it!
But this might be where it is wrong:
The colour of the cable at the c.t. end matters only for whether it records the power as positive or negative. So you can exchange blue and brown at the c.t. end to correct a negative power reading.
The problem could be at the other end. The plug TIP is the common connection to all three c.t’s, like in my drawing in post 50. (The longest line of the ‘plug’ represents the tip, the shortest the sleeve. They match the socket. ) Therefore the common wire for all 3 c.t’s (forget the colour at the c.t. end) must go to the tip of all 3 jack plugs, and the wire that is separate for each c.t. goes to the sleeve. I thought we had corrected that earlier.
I just tried to run the Emley sketch without CT’s and only AC:AC adapter connected, set the “currentSensorPin” to 1.
It recorded just:
millis() now = 0
recordingMayStartAt 5000
And nothing more.
I do not understand that. It works for me! You have byte voltageSensorPin = 0;
and you have not changed that? That must mean that you do not have power to your a.c. adapter, or it is faulty. Can you measure the voltage from it? You should read about 11.5 V a.c.
To clarify, I never changed “voltageSensorPin” which was set to 2 when I downloaded the sketch. And more, I had all the common connection to TIP of the 3.5mm connector.
Now changed it to 0 and ran the serial monitor:
No of cycles recorded = 3 cycleCount 254, samplesRecorded 229
c v. |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c . v |
c v. |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
c v . |
Looks just great I guess ?
Now, how would this change anything (me thinking out loud)
It will make it possible for me to see which c.t. should be connected to which input. That is a relief. I was beginning to think that your emonTx might be damaged - in the end it was a silly slip-up between Robin’s hardware and the standard emonTx V3.
If you can now run the first test again, once for each c.t. and changing only the current sensor pin from 1 to 2 and to 3, and with your toaster as a load, we will be able to get each phase on the correct input, and the c.t. orientation correct.
What you should be looking for is:
The c.t. on input 1 should be exactly aligned with the voltage, as in the first diagram of my early post (39). If it is like the second diagram, exchange brown & blue for that c.t. only.
The c.t. on input 2 should be moved down the page by one third of a complete cycle, so it should cross the centre ( . ) in the same direction as the first crossing of the voltage but on about the 14th line. If it crosses in the opposite direction, exchange brown & blue for that c.t. only.
The c.t. on input 3 should be moved down the page by two thirds of a complete cycle, so it should cross the centre ( . ) in the same direction as the first crossing of the voltage but on about the 26th line. If it crosses in the opposite direction, exchange brown & blue for that c.t. only.
When you have that, you should have all the c.t’s connected correctly, and you can go back to the 3-phase sketch. Hopefully, all your powers will be right.
My uneducated guess: Switch place on input 2 and 3 ?!
Input 1:
| vc |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| . c v |
| .c v |
| c. |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| v c . |
| vc |
Input 2:
| v . c |
| . c |
| . c v |
| . c v |
| .c v |
| c v |
| c. v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c v |
| c . |
| v c . |
| v c . |
| v c . |
| v c. |
| v c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| . vc |
| . c v |
| . c v |
| .c v |
| c v |
Input 3:
| c v. |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c . v |
| c. v |
| . c v |
| . c v |
| . c v |
| . c v |
| . vc |
| . v c |
| v. c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v . c |
| v .c |
| v c . |
| v c . |
| v c . |
| v c . |
| cv . |
| c v . |
| c v. |
| c . v |
| c . v |
Did change input 2 and 3 and got positive readings like the other day. Seems ok. Only thing is, looking at the main meter, it reports 2500w. EmonCMS total sum of three inputs is around 500w higher all the time. How can that be handled ?
No, after 60 posts in this thread, it was an educated guess
Calibration.
Those extra burden resistors you have used are 5% tolerance, the SMT ones are 1%, so together, in the worst case, those could be giving you an error of about 2.5%.
The voltage calibration constant for your Euro adapter should be 260.0 - the value in the sketch will give you an error of 6.5% - assuming it is giving the correct voltage. But these errors - don’t add up to the 20% that you need to bring your output down by.
First, I suggest you put the correct voltage calibration in the sketch: double Vcal = 276.9;
If you can measure the voltage and compare it with the value that the emonTx is telling you, then adjust the number so that you read the correct voltage.
Then, probably the easiest way is to adjust the “scales = …” numbers in emonhub.conf so that the power on each phase agrees with your meter. The first 3 numbers are the powers. So assuming each phase power is now 20% too high, and the total the same, that line in emonhub.conf should read:
scales = 0.833,0.833,0.833,1,0.01, ... [etc]
(1/1.2 = 0.833)
If you prefer, you could adjust the current calibration constants in the sketch instead. You have already changed those to the correct theoretical value, but that did not take account of the actual component values differing from their nominal values.
