No output from CT2 from emonTX - RESOLVED

Hi hope someone can help,

I am getting readings from CT1 and C T3  - tested using the Home Energy Monitor sketch on emonGLCD (and editing the emontx.power# ) , however  I'm getting no output from CT2, - it's not the CT, i've swapped them around, it;s definitely the port.

Can anyone give me a step by step troubleshooting guide on what to look for / check in what order - it's obviously a problem with the way I've wired the / assembled the emonTX

Robert Wall's picture

Re: No output from CT2 from emonTX - RESOLVED

The first suspicion lies with the jack socket - these have been the cause of problems in the past. If this proves to be OK, you could check the voltage on the burden resistor (18 Ohms, the one nearest the corner of the board), you should see 1.65 V d.c. (+/- 2% or so) on each end. Also check that the adjacent capacitor is inserted the correct way round (especially if the voltage is incorrect) - the broad white band should be to the edge of the pcb.  If you have a multimeter with a millivolts a.c. range, you could check the voltage across the burden resistor - you should see 9 mV per Amp of current when the c.t. is connected.

Avontech's picture

Re: No output from CT2 from emonTX - RESOLVED

Many thanks Robert - spot on actually I just found it myself and was coming back to say so!!

I did a quick check with a multimeter and got consistent results across all three feeds so then physically inserted the CT jack into the plug and noticed it wasn't quite all the way in. A little bit of extra muscle, quick check and now up and running.

Once again many thanks

My next task is ti put my coding head on as I've got three inverters (14kwp) and 3 CU's all on the same single phase (I have a very tolerant and generous DNO ! ) so I want to collect all the details about which inverters and pv arrangements are performing best and what's using the power (apart from my 16 year old's bedroom aka electronics warehouse :) )  Goal is then to use RPi as an emonCMS - it's already collecting weather data so that I can monitor the PV systems performances to the nth degree.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.