Hi everyone,
I'm just in the process of commissioning another emonTX V2.
I'm using an existing sketch that I know to be working correctly. I can measure mains voltage using the AC/AC adapter and the attenuator circuit without issue.
When I try to measure a known current on any of the CT inputs the measurement is a flat line at code 512 or 513. If I substitute an equivalent CT in place of the shop purchased YHDC unit I can measure pretty well the expected current. Same behaviour occurs on all 3 CT inputs.
Impedance across the coil is about 100 ohms on both the working and non working units.
No end of inserting silver paper, etc, in the jaws makes the slightest difference to the reading obtained on the non functional CT unit.
Is it reasonable to assume that the CT is dead or can you suggest any further checks that I can perform?
kind regards and thanks.
Ian
Re: Problem with current transformer
I once had a CT that wouldn't behave despite doing all the kinds of things that you've tried. Turned out that the jack plug was not quite making contact within the socket. This can occur if the emonTx or similar is slightly loose on its mountings.
I've also had one faulty CT which was easily sorted, albeit rather a fiddly operation. Both ends of the unit can be dismantled so I would be surprised if it can't be fixed.
Re: Problem with current transformer
...I've had problems with the jack plugs themselves, I replaced them with Neutrik Rean plugs which have performed well.
NOTE - the ones I had problems with were NOT purchased from the OEM shop.
Paul
Re: Problem with current transformer
The usual problem is the socket on the pcb is very stiff, so the plug is not fully inserted and the contact springs sit on the insulation between the parts, not on the metal. Unscrew the plastic cover so that it's just flush with the body, then, if you can see any sleeve, it's not fully home.
It is wired correctly - to tip and sleeve?
Re: Problem with current transformer
...I've had problems with the jack plugs themselves, I replaced them with Neutrik Rean plugs which have performed well.
like this?
Re: Problem with current transformer
Thanks everyone,
in the end it was down to me forgetting that new plugs and sockets need to be introduced to one another with "hammer force". Once I did that everything sprang to life.
After much of today "playing" with hardware and software I now have a system which allows me measure the energy directly sent to my immersion heater via a wireless connection to my nanode hub and then on to emoncms. It's difficult to do this directly with math because the wiring in my house doesn't seem to offer a single feed to the immersion heater from the consumer unit.
With my system now I can measure the various sets of consumption/generation data into the house and through the solar generation circuitry as well as monitor the energy dumped into the immersion heater using the software initiated by Robin. I can also read the Elster AC100 meter. All of this is then sent to the web and stored on my web page on the emoncms server and I can monitor this from anywhere via the web.
thanks for your help.
Ian
Re: Problem with current transformer
...I've had problems with the jack plugs themselves, I replaced them with Neutrik Rean plugs which have performed well.
like this?
Well I used these from Ebay and paid about £2 each inc postage. They are really professional quality and I've not had any problems whatsoever since.
The only downside is the metal sleeve - which may be a problem if it's unplugged whilst the sun is shining and CT clamped!
Paul