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The power readings cannot be correct until they get a correct voltage signal to calculate from.

"Voltage: 128*255+184 = 32,824*3.3/1024 = 105V  (Here we have 220V which is strange."

I'm not sure where this comes from, the "voltage" integer from the emonTx is calculated to an actual voltage reading but scaled by 100 to give accuracy to 2 decimal places. It is also a signed integer so the result actually reports -325.83v which is even stranger !!

What power supplies are you using ? Just a AC/AC or a combination of AC/AC and Battery or AC/DC ?

Are you using a "stock" sketch in the emonTx?

Paul

edit - Plus if using a AC/AC is it definitely linear NOT switched mode ?

Thanks pb66 for your answer. I am using just AC/AC power. I am uploading emonTX firmware through the arduino IDE, the firmware that I am uploading is emotxV3_4_Discrete_Sampling with RF12. The AC adapter that I am using is the one that I bought from Open Energy. Any ideas?

What do you see on a serial monitor connected to the emonTx?

Hi Robert, I see the following:

emonTx V3.4 Discrete Sampling V1.80 RFM12B
OpenEnergyMonitor.org
POST.....wait 10s
CT 1 Cal 90.90
CT 2 Cal 90.90
CT 3 Cal 90.90
CT 4 Cal 16.67
RMS Voltage on AC-AC  is: ~245V
AC-AC detected - Real Power measure enabled
assuming pwr from AC-AC (jumper closed)
Vcal: 245.53
Phase Shift: 1.70
CT 1 detected
No temperature sensor
RFM12B
Node: 10 Freq: 433Mhz Network: 210
CT1 CT2 CT3 CT4 VRMS/BATT PULSE 
14333 0 0 0 29727 1  
14353 0 0 0 29782 1  
14973 0 0 0 30288 1  
 

Regards,

NK

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I'm puzzled by the voltage you're measuring. You've said the nominal voltage is 220 V, yet it is showing as about 300 V. What is the exact type of ac adapter that you have? (It should be either 77DB-06-09 or 77DE-06-09. If it is a 77DA-10-09, STOP USING IT IMMEDIATELY - it is a 120 V version.)

Can you measure the no-load voltage from the adapter? It should be about 11 V ac.

What is also puzzling is why the Vac appears to be escalating (or at least fluctuating wildly), reported as "RMS Voltage on AC-AC  is: ~245V"  early in the serial print then 297-302v, the original post shows a voltage consistently in the region of 322-329v (ignoring roll-over to signed) presumably after it has been on for a while.

A previous thread (EmonTx RF12 Data Format Doubt) shows values 250-251v has anything changed since then ?

The "Vcal: 245.53" suggests you have calibrated, presumably for use at 220v (currently 268.97 in that sketch) ? although I'm not sure it would be totally necessary (or that different) for a 230v adapter as Vcal follows the AC/AC transformer ratio rather than the supply voltage. Did you change anything else in the sketch?

Paul

Paul, don't worry too much about the first voltage report in the header - it is a quick only approximately calibrated measurement aimed at checking whether the supply is there or not.

fair point - I wasn't concerned so much about the value for just that reason, but just thought the >20% jump in next to no time was odd considering I don't recall ever seeing any initial confirmations in the region of 180v for a normal 230v system

I hadn't linked that other thread to this, something is definitely not the same, yet the calibration values are not so far out as to give a voltage 36% high. There's something really wrong somewhere.
That initial voltage might include a dc offset so it's not totally reliable, it's the raw rms count times 0.87 So the rms count is 282, which gives an ADC input voltage of 0.91 V rms, so given a 10 kΩ : 120 kΩ divider, that's 11.83 V out of the adapter and almost exactly what I'd expect. If it's the Euro adapter, the ratio is 230 V in for 11.5 V out (±5%), hence 236.6 V supply - inside 220 V ±10% and entirely credible. So it looks as if I was wrong to suspect the adapter, and something has changed in the sketch.

Thanks guys. There sure is something strange about this because we can't that voltage variations in the network. But again, everything is strange with the meassurements.

The answers to your questions below:

What is the exact type of ac adapter that you have?

06-09. I attach a picture of it just in case.

Can you measure the no-load voltage from the adapter?

11.33V

Did you change anything else in the sketch?

I changed two things in the sketch. I changed Vcal in a desperate way to see some changes, it was due only to my level of desperation by not seeing any progress in over 6 hours. The second thing that I changed is RF69_COMPAT value to 0, because I am using an RF12.

Hi Paul,

Tha thread was on other issue that was solved thanks to Robert's answer.

Regards,

NK

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When I went to the other thread I noticed something different about the output of the info send to the RPI through the RF12B.

The lines at the other post are in the following form:

10 199 247 0 0 0 0 0 0 64 98 0 0

And in the sketch that I installed in this emonTX (it is a different one), the lines are in the following format:

OK 10 201 55 20 65 42 62 0 0 3 126 0 0 0 0 0 0 0 0 0 0 0 0 1 0 (-74)

The sketch that I installed is the one from this link https://github.com/openenergymonitor/emonTxFirmware/blob/master/emonTxV3/RFM/emonTxV3.4/emonTxV3_4_DiscreteSampling/emonTxV3_4_DiscreteSampling.ino obviously with the changes on RF69 and Vcal.

NK - I wasn't suggesting it was the same issue, just referencing the voltage readings and asking if anything had changed. I can see the sketch has changed by the number of variables in the payload but we cannot tell if it's the same emonTx and/or power supply arrangements.

If the power supply is able to connect to the mains either way round can you also try reversing the connection to switch the phase of the ac adapter. if 180° out wouldn't the effect of the rectifier impact the waveform differently?

Paul

Your ac adapter is the Euro version (DE-), the nominal input voltage is 230 V, the no-load output is 11.5 V (±5%), so this is OK. Your voltage calibration for that should be 260.0
The value you have is wrong by 6%, not 36%, so there is something else wrong also.

RF69_COMPAT = 0 is correct for the RFM12B. (The sketch would lock up and not run if that was wrong.)

The extra data in your sketch is for 6 × unused temperature sensors plus pulse count (also unused?), so that is not the problem - not this one [those have caused other problems recently, so beware!]

The data (following "OK 10") are all signed integers:
power1, power2, power3, power4, Vrms, temp[6], pulseCount sent LSB first.

None of this explains why you are seeing ~300 V, I think you need to attach your sketch as you have it now so that we can do a line-by-line comparison. I suspect something has been changed by accident.

[Edit] Paul, changing the phase of the AC adapter is equivalent to flipping the CT's - it reverses the direction of real power.

"10 199 247 0 0 0 0 0 0 64 98 0 0"

Is a packet from a single temperature sensor sketch the latest has provision for 6

"OK 10 201 55 20 65 42 62 0 0 3 126 0 0 0 0 0 0 0 0 0 0 0 0 1 0 (-74)"

Also has a "OK" prefix and a trailing RSSI, this tells us the later was recieved on a rfm69 equiped RFM2Pi or RFM69Pi or emonPi whilst the former was probally recieved on a rfm12 RFM2Pi.

the important difference is the values in bold 251.52v in the first payload and 322.59v in the second,

Paul

Thanks again for your help guys. I attach the sketch so you can take a look at it.

Regards,

Nicolas

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I don't believe it - except for the Vcal value (which does not explain all of the discrepancy), it is identical to my saved copy.

There has to be a fault or a wrong component in your emonTx. I'll refer this to Glyn.

Thanks Robert, it is indeed very strange, I thought the same because I have another emontx that has been working perfect for more than 6 months. Thanks for your help and I hope that Glyn has some idea of what could be happening and if it could have a solution.

Regards,

Nicolás

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Hi Nicolás,

It sounds like you may have a faulty emonTx unit. I'm very sorry about this. Please could you email support@openenergymonitor.zendesk.com and quote your original order number. We will arrange for you to be sent a replacement.

Very sorry for the hassle. 

Hi guys,

 Just writting to let you know that I received a replacement emontxv3 and it worked liked a charm at it's first connection. The board was faulty. Thanks for the help, I'm renaming this as solved.

Regards,

NK

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