Unusual 0W readings

phogg · 2018-08-16T04:37:20.941Z

Hi,

I’ve been using a good number of emonTX units talking to an EmonPi for over a year and in the last week 1 of the emonTX units keeps erratically reporting 0V in between correct reads (1 read in perhaps 50 might be incorrect). All the other units still seem to be operating business as usual. Has anyone else experienced anything similar?

Many thanks,
Phill

Robert.Wall · 2018-08-16T15:42:32.677Z

I cannot remember anyone ever reporting that problem. Has anything “unusual” happened recently - abnormal temperature? Any clues in the emonPi log?

How is the emonTx powered - via 5 V USB or the a.c. adapter?

How many c.t. inputs are affected?

Are the power readings either side of the zero normal?

Is the accompanying voltage reading normal?

Have you looked for all the silly things, like a corroded c.t. connection?

I can only think of two things that could make it report a true zero - a short or open circuit in the c.t., or (most unlikely) another device sending a message that both masquerades as that emonTx and sends a syntactically correct message showing zero power.

phogg · 2018-08-16T20:57:05.063Z

Thanks Robert - you were on the money.

I have a unit rigged up to a 4G router which had come back into the office a day or so ago with the same node ID and batteries in it and that was reporting over the top of the unit I was expecting to see.

Crisis averted!

Phill