New iotawatt, no voltage or power readings - resolved


I’m in the UK and have just got iotawatt, 9v ac ref [Ideal 77DB-06-09(UK)], and 3 CT SCT013-000

Device powered up ok, wifi and browser connection all work fine, setup appeared ok … but …

Inputs all reading as 0v and 0w

I have tested the AC ref (digi multimeter, ac voltage measurement) and it appears to be outputting as 0V +/- 0.1V, and checked multimeter against another LV AC adapter to verify not a multimeter issue

I have an old energymonitor with CTs so I also know the circuits i am measuring are drawing current

The status page is showing sampling is happening (see pic)

Does the iotawatt require the ac ref to be functioning to measure and display the CT measurements?

If so, implies my AC ref is a dud? openenergymonitor are replacing it just in case

If this is the case, might be worth updating the FAQ/troubleshooting to reflect this or adding a log entry when 0V ref is detected

If not, any ideas what I might be doing wrong or what might be wrong?

Many thanks!

Yes. Voltage is needed both to define the AC cycles and to compute real-power.

Before you connect the new VT, you might check that the new one has about 11 volts output before connecting to the IoTaWatt for the first time in the unlikely event that the IoTaWatt input is overloading the VT and blowing the fuse.

Get back to me if the new VT doesn’t solve your problem.

Thanks @overeasy

New VT solved problems :slight_smile:

now the fun can start