Since installation, emoncms is displaying a value about 24x that of the LCD on the emonpi. While the emonpi reads a believable 3Kw, emoncms displays 73Kw.
I’m using the pulse input. emonpi seems not to detect the CT.
Any suggestions appreciated.
Welcome, John to the OEM forum.
Both displays come from the same source, so you must have something in the processing in emonHub or in emonCMS that’s multiplying the pulse count.
Where and how have you installed your c.t? Is it on your meter tail, like the picture here: Install emonTx & emonBase - Guide | OpenEnergyMonitor
Is the plug fully inserted?
Do you have an a.c. adapter - and was it switched on and powered before or at the same time as the d.c. supply to the emonPi?
Look in emonHub.conf (“emonHub” then “edit config” from the Setup menu. The entry for Node 5 should look like this:
[[5]]
nodename = emonpi
[[[rx]]]
names = power1,power2,power1pluspower2,vrms,t1,t2,t3,t4,t5,t6,pulsecount
datacodes = h, h, h, h, h, h, h, h, h, h, L
scales = 1,1,1,0.01,0.1,0.1,0.1,0.1,0.1,0.1,1
units = W,W,W,V,C,C,C,C,C,C,p
In particular, check the numbers in “scales =…”
Hi Robert, thank you for the greeting.
I’m sorry to have included two different issues in the same post.
CT not detected:
The current transformer is closed across a meter tail (a single core). The ct is one bought from the store. It has continuity - about 72 ohms - between the sleeve and tip of the jack. These pins correspond with the schematic. I have tried it in ct1 and ct2 and have rebooted several times however early in the boot the display shows “no AC detected”. Is that to do with expectation of an AC adaptor or the feed from the current transformer?
Readings disparity:
I don’t have an AC adaptor - as yet.
The emonHub node 5 entries seem to be the same as your post. Copied and pasted here in case I am blind to something:
[[5]]
nodename = emonpi
[[[rx]]]
names = power1,power2,power1pluspower2,vrms,t1,t2,t3,t4,t5,t6,pulsecount
datacodes = h, h, h, h, h, h, h, h, h, h, L
scales = 1,1,1,0.01,0.1,0.1,0.1,0.1,0.1,0.1,1
units = W,W,W,V,C,C,C,C,C,C,p
Thanks.
It’s probably best that you did, because the issues might well have been related. They might still be.
That refers to the a.c. voltage sensed (or not, in your case) by the a.c. adapter.
Was the c.t. plugged in when you powered your emonPi? As the FAQ says, both a.c. adapter and c.t. are detected at power-up, rebooting the Pi is not enough. If it wasn’t plugged in, you must do a controlled shutdown of the Pi, then power down and power up again.
All those numbers in emonHub look OK.
I’m trying to remember what the emonPi displays normally. I can’t look at mine because it’s got a modified test version of the software in it. When you wrote “emoncms displays 73Kw.”, where exactly in emonCMS?
The first place to see the data is in the emonHub log. The lines that show the c.t. inputs look like this:
2020-10-03 19:12:16,247 DEBUG MQTT Publishing: emon/emonpiCM/power1 243
2020-10-03 19:12:16,249 DEBUG MQTT Publishing: emon/emonpiCM/power2 222
2020-10-03 19:12:16,251 DEBUG MQTT Publishing: emon/emonpiCM/power1pluspower2 465
2020-10-03 19:12:16,253 DEBUG MQTT Publishing: emon/emonpiCM/vrms 235.88
- 243 W and 222 W on the two c.t’s respectively. If both those are zero, then you have a c.t. problem, either it hasn’t been recognised, or it’s faulty - and I wonder about that, because 72 Ω is a bit low, it should be nearer 100 Ω.
How are you processing the pulses in emonCMS?
Thank you for your help Robert. As I dug deeper I realised there was so much wrong that I made a fresh Emon sd image. It seems to work fine now 
And I’ve ordered an AC-AC transformer to improve the accuracy.
So the problem - maybe put a little harshly but not intended to offend - was you finding your way around and you messed it up. There’s another couple of words for that: “Learning curve”. Whatever else, don’t be put off. There’s an awful lot to learn here, and on the whole a pretty helpful and willing bunch of contributors who’ll help you.
Just remember you’ve got to power down (not just reboot the Pi) for it to recognise the new a.c. input.
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Robert, you are most probably right! Thanks for taking the time to help.
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