New Installation - Australia, Regional NSW

14 posts were split to a new topic: Wifi problems mesh router

That’s only a rare occurrence, e.g. if I need to take the off-grid system offline for maintenance or something like that.

In any case the RED and WHITE VTs will still be on their respective phase and be unaffected.

It depends.

If the off-grid system is in grid-pass through (Utility First) mode, then the grid supplies the phase timing. The power is a straight pass through.

If the off-grid system is not operating in grid-pass through mode, then the off-grid system is supplying the phase timing.

Which is why the BLUE phase VT is supplied power from the output of the off-grid inverter - so that the phase timing it supplies is in alignment with whatever the source of the power is, be it a grid pass through or generated by the off-grid inverter.

This is why I went with individual VTs.

So if I did need to flip the transfer switch back to grid-only (e.g. for off-grid maintenance), then in that time, I can either simply change the VT settings for those circuits back to their original phase, or not be fussed with having incorrect data if the downtime is short.

I would need to read this again in the morning after a couple of cups of coffee, and maybe make a line drawing (picture worth a thousand words - hint hint). But one thing that glares out at me is what appears to be needless complexity of the essential load handling.

Correct me if I’m wrong, but I think you are saying that the essential loads are connected to the three grid phases in one position of the transfer switch, but all three phases are connected to the Blue single phase in the other, which you say is “normal” mode.

I have to ask: Why not just make the essential system single phase all of the time? Then you would have a single-phase essential system and a three-phase non-essential system.

Another, probably simpler approach, would be to activate derived reference and use a derived Blue reference for any Blue loads on the non-essential side. Use of direct and derived are not at all mutually exclusive, in fact if any of your three-phase loads are three-wire, you can use derived reference to measure them with only two CTs.

You might need some Nodoze as well :slight_smile:

Ordinarily I’d agree. Hindsight is 20:20 and all that.

But I have what I have and there are various historical reasons including the power distributor wrangling I had to go through to get approval to build the second dwelling for my elderly mother, (who sadly passed away earlier this year). They required two things:

  • the second dwelling also have 3-phase supply
  • the entire property be capped to 32 A/phase

The whole thing grew out of the fact we average a dozen longer grid outages a year on average. I kept records of them all for years. Plus all the countless short duration outages.

With just the two of us here, I previously managed longer outages with a generator, a power inlet and the transfer switch and it was a reasonable effective way to deal with it.

But with the new dwelling for my mum (which I now refer to as the studio) and my work from home wife not being able to move/operate the generator, if I was not here then they would be without power and that was not acceptable to me. Aside from my wife’s work, it can get very hot here and heat can kill the elderly and that wasn’t going to happen on my watch. My mum in her twilight years was going to have the safety and power security she deserved.

So I set up an off-grid PV/battery system to replace the role of the generator. I found it worked very well and could be automated to do a whole lot more, so I expanded it.

And it works really well so why change it? I might even add more PV and battery to it but for now it does a great job. 10 kWh of LiFePO4 for daily cycling duties, 20 kWh of sealed lead acid data centre backup batteries in reserve for those extended power outages and we are not getting left hanging.

I had hoped the fact the outbuildings had three active wires each would enable some level of circuit level monitoring for the two outbuildings as effectively I have three individual circuits going to them.

But maybe the answer is to put it all ESSENTIAL circuits on BLUE phase, including running the outbuildings via BLUE only.

It would be possible. But would it be wise? I’ll have to think that one through.

Let me have a go. I am butchering a transfer switch wiring diagram.

Here is a 3-phase transfer switch diagram to show the way ESSENTIAL loads circuits are supplied:

And some photos. Under the transfer switch (ignore the 3-pole switch on the left - that’s the main supply breaker):

And from the top:

When switch is UP (GRID SUPPLY) then the grid supply is fed through to ESSENTIAL loads via R, W, B (shown on the actual switch as R, S, T) and all circuits operate as a regular 3-phase supply.

When the switch is down (OFF-GRID SUPPLY), then the single phase OFF-GRID supply is fed through to ESSENTIAL loads via G1, G2, G3, which are linked.

Naturally when the switch is in the middle position then neither supply is connected (break before make).

Now to make things fun, the off-grid inverter can generate its own power (using solar PV and/or battery), or it can pass through GRID power coming from the BLUE phase.

Naturally the circuit feeding the AC input for the off-grid inverter is one of the NON-ESSENTIAL circuits not supplied via the transfer switch (else I would have nasty feedback loops).

My “normal” mode of operation is for the transfer switch to be left in the down OFF-GRID position.

This means ESSENTIAL LOADS, which include the Studio 3-pole breaker plus this panel which also includes the Mancave 3-pole breaker:

are all getting a single phase supply via the off-grid inverter, be it grid power passed through the off-grid inverter, or power supplied by the off-grid inverter from the off-grid PV and battery.

I hope that all makes a bit more sense.

And to top things off, I seem to have weird Wi-Fi network issues (which I profess to not understand).

The IotaWatt is located near a mesh router for good signal. Even so, it seems to drop off the network and get lost. I do so wish it had an ethernet port to connect to. I grow weary of Wi-Fi hassles.

Today was a long outage between 9AM and 1:30PM.

Today’s log:

** Restart **

SD initialized.
3/22/23 02:06:23z Real Time Clock is running. Unix time 1679450783 
3/22/23 02:06:23z Reset reason: Software/System restart
3/22/23 02:06:23z Trace:  1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:3, 1:1[14], 1:2, 9:0, 9:0, 8:4, 8:6, 8:8, 1:3, 10:2, 10:3
3/22/23 02:06:23z ESP8266 ID: 15763621, RTC PCF8523 (68)
3/22/23 02:06:23z IoTaWatt 5.0, Firmware version 02_08_02
3/22/23 02:06:23z SPIFFS mounted.
3/22/23 13:06:23 Local time zone: +10:00, using DST/BST when in effect.
3/22/23 13:06:23 device name: IotaWatt
3/22/23 13:06:23 HTTP server started
3/22/23 13:06:23 timeSync: service started.
3/22/23 13:06:23 statService: started.
3/22/23 13:06:24 dataLog: service started.
3/22/23 13:06:24 dataLog: Last log entry 03/22/23 13:06:20
3/22/23 13:06:27 WiFi connected. SSID=Telstra25BEB0, IP=, channel=6, RSSI -66db
3/22/23 13:06:27 Updater: service started. Auto-update class is MINOR
3/22/23 13:06:28 historyLog: service started.
3/22/23 13:06:28 historyLog: Last log entry 03/22/23 13:06:00
3/22/23 13:06:28 Updater: Auto-update is current for class MINOR.
3/22/23 18:55:00 WiFi disconnected.
3/22/23 18:59:11 WiFi connected. SSID=Telstra25BEB0, IP=, channel=11, RSSI -80db
3/22/23 18:59:24 WiFi disconnected.
3/22/23 18:59:28 WiFi connected. SSID=Telstra25BEB0, IP=, channel=1, RSSI -51db
3/22/23 19:07:09 Updater: Invalid response from server. HTTPcode: -4
3/23/23 00:59:33 WiFi disconnected.
3/23/23 00:59:42 WiFi connected. SSID=Telstra25BEB0, IP=, channel=11, RSSI -76db
3/23/23 01:34:03 WiFi disconnected.
3/23/23 01:34:09 WiFi connected. SSID=Telstra25BEB0, IP=, channel=11, RSSI -76db
3/23/23 02:00:24 WiFi disconnected.
3/23/23 02:00:28 WiFi connected. SSID=Telstra25BEB0, IP=, channel=6, RSSI -51db

I don’t know much about networking but it seems like this device can’t make up its mind where to connect to.

Even so, is the data not still captured internally?


My 2.4 GHz and 5 GHz Wi-Fi have separate SSIDs.

My IotaWatt is ~2 metres from the mesh extender.

But it’s something I can try.

I still don’t fully understand your setup, and probably can’t without emmersing myself in the workings of your off-grid inverter (not going to do that). So, maybe there’s an explanation for this, but I find it strange:
The names imply these are the grid input to the inverter and the output to essential loads. Notice the power factor of the input. That can’t be right.

Both of these are configured with reference 14 or Blue phase. If I understand correctly from your description the VT is on the “out” side of the inverter. I think the output phase is produced by the inverter, and that any AC input is being converted to DC and then fed to the battery and inverter. I suspect the Blue phase out of the inverter is never the same as the grid blue phase.

I previously suggested that you try using derived reference for the grid side of the blue phase. I’ll give it another try. It would be pretty easy to do:

  • Check the “Enable derived three-phase” box in the inputs setup. This will not change anything with your direct reference setup.

  • Edit OFFGRID_AC_IN_4 to use Phase_RED for Vref, and then select “Mains Phase” B.

  • I suspect that with the correct phase reference, the power factor will be quite high. See if it’s .9 or greater. If not try setting to “Mains Phase” C.

Yes, it’s a good spot.

The issue is this:

The VT is using the off-grid inverter’s output voltage as reference.

When grid power is being passed through the inverter (e.g. daytime), then the AC input and AC output voltages match, and will be the same as the grid phase BLUE.

However when grid power is NOT being passed through, then the AC output voltage is is different to the AC input voltage. The output voltage will be what the inverter supplies (a steady 230 V) while the input voltage will be the grid phase BLUE.

Naturally in this mode there is almost no AC power being delivered into the off-grid inverter (although it does have a bit of annoying idle power consumption from the AC input).

I hadn’t ignored it, I just didn’t think it was possible to have both a VT and a derived phase voltage at the same time. I’ll have a go and report back, thanks.

OK, this is the new derived phase set up for the AC input:

And this is the set up for the AC output:

And the status screen:


When looking at the data for the AC input and output power factors, it’s not reporting the output PF at all - or rather the data is stuck at a fixed value. See this chart:

Can see where I made the change to the AC Input and adjusted the phase angle adjustment setting a couple of times.

But the AC output PF is not moving - it is stuck.

It’s the same for the power output:

I see this across a number of the data channels - the data just stops reporting and it goes flat line at whatever the last value was.

e.g. the Studio power data did this yesterday:

and others show the same thing happening.

The status display that you posted with realistic Power and PF for both input and output was at 11:50. The plot you are showing with the “stuck” values shows good PF data at 11:50, and the “stuck” PF value for output is .93 which is what the status display says. Not saying there is no problem, but I don’t see the case for it. I don’t know what happened before 11:50.

OK, here’s what I mean:

If we look at the trace for the inverter’s AC power output (blue line) we can see long periods where it gets stuck at one value.

Meanwhile this is what the power output is actually doing over that same time period (as reported by the inverter):

Up until about 10:45AM the two charts are showing the same pattern for power output. But then the IotaWatt data just freezes at a fixed value and it goes flat line. Every now and then it moves to a new value and then flat lines again.

But that’s not representative of what the actual power values are.

The status page shows the same power output and PF value it was show several hours ago:

I’m trying to understand why this data just stops being recorded and just goes flat line. I’m seeing this happen in several of the charts. The time periods it occurs vary.

e.g. the PF for the AC output shows the same behaviour:

And another, here is the power values for the Studio today so far:

Just before midday the data stops being recorded and goes flat line.

Meanwhile the ducted aircon channel was capturing data the whole time:

Can you plot the three voltages for the same period?


I do appreciate the assistance.

The voltage jump (blue) at about 8:30AM would be the off-grid system cutting over from supplying power from battery to passing through grid power.

Then just before midday yesterday (same as the other charts) can see the voltage also goes flat line.

And for reference, here’s the output voltage as reported by the off-grid inverter for the same time period:

I thought so. There’s something Janky about the Blue offgrid voltage. Clearly there’s a changeover of some sort at about 8:40 am. Was that pure inverter output before then? After 8:40 I can see that the IoTaWatt is unable to lock on to the voltage signal, not just after 11:50, but there are also a few short flatlines on each side of 11:00am and probably some smaller episodes as well.

In order to detect a voltage signal, the zero crossings must be pretty clean. If its not a smooth sine-wave, where the maximum slope is at zero crossing, the voltage is cannot be sensed and power cannot be measured.


The inverter is supplying power during the night using energy from the battery, then at some stage in the morning it cuts over to pass through grid power. In this case a little after 8:30AM yesterday.

Here’s a zoomed in look at that period just before and after the change from inverter to grid supply:

I get this might be an issue for the brief moments of supply change over (although I note it did pick up that transition yesterday morning), but why would it go flat line for hours on end?

OK, this morning’s change over just happened a few minutes ago:

It picked up the change over no issues.

Will monitor today to see how it goes.

Do you still have the offgrid_AC_in using derived reference? If so, can you plot AC in and out together?


Here is the AC power in and out from the inverter over last 30-min:

Can see the change over, and that peak on the right is my wife making a cup of tea (an instant hot water dispenser).

Here is the voltage chart for the same period:

Some flat line periods showing in both charts.

Yes, I can see the water heater. You can see where the voltage starts to flatline before that, just after 8:22, then the water heater comes on just after 8:24. After a few seconds the AC-out voltage gets another sample and jumps up to match the AC-in. When the water heater shuts down a minute later it leaves the AC-out hanging in the frozen state.

The AC signal from the offgrid blue VT seems to be producing a signal that IoTaWatt cannot recognize. It has to do with how IoTwAtt samples. Most other meters just keep sampling without regard for individual cycles. IoTaWatt samples individual cycles and needs to be able to identify the start, midpoint and end by looking for zero crossings. I suspect the signal is getting muddied, possibly the inverter is using a triac to switch in the line AC rather than a contact relay.

Let’s take a look at that signal. Use the command


You should get a list of sample pairs. Do this while it is not “stuck” and retry if it fails. Copy and paste the results into a notepad type file and upload it.