Which sketch for 3 phase multiple RF loads


I’m currently using an EmonTxV3_4 with Continuous Monitoring firmware on my 3-phase installation. As a next step for the project I would like to start diverting energy, but I’m struggling to select the right firmware based on choosing-an-energy-diverter .

-installation: 4-wire 3xL+N (400V)
-single phase solar PV (most of the load in the house is on this phase already)
-primary load is remote
-a secondary load is ideally remote, but could be considered local if required

Initially I was planning on using:

  • emonTx_Solar_Controller_Temperature_PLL_LCD_3Phase.ino by Petrik
    but from reading through the sketch I don’t think this sketch supports a remote RF controlled load.

Looking at Robin Emley’s Mk2 variants listed in the comparison table I found:

  • Mk2i_PV_Router_rev5e.ino which supports 2 loads of which 1 can be remote. But no 3phase support afaik.

The archived variants page also lists:

Any pointers greatly appreciated.

The first thing you need to know is, do you have nett metering? Do you pay for import on the other two phases when you’re exporting more on the ‘solar’ phase? The answer to this will affect how you divert energy.

Basically, and especially as far as the processor itself goes, anything for Robin’s MK2 can run on an emonTx of any vintage, and vice versa. The difficulty comes with things like radios, temperature, pulse inputs, extra switches and the general use of the I/O pins. Changing those is simple enough when you know what to change.

You can’t use Robin’s 3-phase sketches as a basis for the emonTx, because his p.c.b. has 3 mains transformers for voltage and 3 c.t inputs for current, so it directly measures the three phases. Our 3-phase sketch has to manufacture the second and third phases internally in order to estimate those powers, because as you know the emonTx has only the one voltage input.

So the answer is, to keep your emonTx you need to take your present 3-phase sketch and add in the sensing and remote control by radio parts of Robin’s sketch. This could be very tricky, the risk is you will lose phase lock if the additional calculations take too long.

A much better and probably easier way would be to buy a 3-phase Mk2 kit less the triac from Robin and graft the remote control part from Mk2_withRemoteLoad_5.ino into his Mk2_3phase_RFdatalog_4.ino sketch instead of the datalogging part, and use that solely for diversion, keeping your emonTx for monitoring. If you have two remote loads controlled over a radio link, you’ll in effect need 2 single phase Mk2 kits as well to receive the signals and drive the triac switches.

Robin’s website is Mk2PVRouter.co.uk

thank you @Robert.Wall

Not yet, currently it is still an analog meter that “runs backwards” so as long as the total consumption across the phases is <0 I’m not paying.
I expect by 2025 I will be forced to install a digital meter (Sagemcom T211) which reports total consumed and total injected power separately. I haven’t been able to find if total injected power and total consumed power can both be non-zero at the same time (or if i’d be billed for consumption on phases 1 and 2 while exporting on phase 3).

In the short term the goal is consume power when it is available, but also to avoid the inverter from tripping constantly due to high voltage when there is a lot of sun. Based on my experiments I can keep the inverter from tripping if I turn on a large enough load, and hence also produce more than when the inverter would be in standby/safety. (currently I can do this with home assistant integration monitoring voltage and driving a smart plug, but since this is binary on/off this is far from optimal)

While very interesting, I’m afraid I’d be out of my depth if I had to debug this.

I had looked into this option, but I get a sense the mk2 routers are “end of life” and it still looks quite complex to setup + additional firmware tinkering required.

Is there any remote load sketches for the EmonTx itself? Even if this would be single phase? Or a single remote load?

There’s been one or more discussions here about that - I think the term Net(t) metering might find it.

Not quite, the kits won’t be produced after the end of this year, but my understanding is Robin will continue to provide support for existing customers. I know the reason - I don’t know if I can say.

No there aren’t. But – it’s only a case of changing the payload from what it normally sends (powers, voltage, energy) to a single 1 or 0 for on/off (or or more precisely, the same message that Robin uses), and using Robin’s receiver sketch in another emonTx or whatever to send out the command to control your remote load.

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