Mk 2 in USA with 248Vac Mains

MK 2 PV Router in USA with 248Vac Mains

On my 248Vac Mains the MK2 pcb’s 230 volt rated control transformer outputs 8 Vac to the pcb and then the DC side of pcb is to run at 3.3v, Is this a problem?

Is there a way to do any calibration to improve how the sketch runs?

Do you understand European power supply? A nominal 230 V supply can be over 250 V in reality (my mains regularly is), up to 253 V. So it’s operating well within it’s specs.

Calibrate what to improve how?

Basically - there is no need. The sketch is actually seeking a zero balance, so amplitude has little impact on the operation, although it might affect the displayed values (if you have that option).

Have you carried out the calibration procedures on Robin’s website ?

Those values sound OK to me. If the voltage from the transformer is rather high, it could cause the voltage regulator to run a bit warmer. Because very little current is drawn by the processor, VR1 generally runs fairly cool. A small heatsink could always be fitted if necessary.

The second output from the transformer is used to provide an AC voltage signal to the processor. Dropper resistors are used to reduce the amplitude so that the resulting signal lies nicely within the working range of the processor’s ADC.

As RW has noted, calibration will have no effect on the control system’s ability to match consumption against generation. Calibration will only affect any datalogged values for average power.

The OP is in the USA. How does the European power supply fit in here?

The OP referred to the nominal European standard voltage, which is observed only in the absence. Continental European voltages are lower in operation, whilst British ones continue to be higher, both continuing in actuality the traditional standards of 220 V and 240 V. And the upper tolerance limit for European voltages continues to be 253 V, exactly the same as the previous British limit.

The US limits are within the European limits, AFAIK.

I’d imagine @djh correctly believes that the design originated in the UK, therefore it was designed with the UK mains supply in mind and would be suitable for that.

OK. I read that as a reference to a component rated at 230 Volts running at 248 Volts,
and a question being asked if the resultant output voltage was a problem.

I’d say it’s a fair bet the European system voltage wasn’t what he was speaking / thinking of.

Many in the US have little or no idea what the voltage standards are in other parts of the world.
They can’t get it straight at home, let alone another part of the world.
Lots of them refer to our 120 / 240 Volt system by the long-outdated term 110 / 220 Volt.
Of course, that’s no excuse for not looking up said information.

Fair enough.
I couldn’t help thinking that there might be some confusion, hence my question.

I’d go along with confusion. I think many ‘dubious’ importers bring in goods labelled “230 V” and believe, whether in ignorance or mistakenly or because they don’t care, that because of harmonisation the UK voltage changed overnight. It didn’t, and as far as I know, it most likely won’t change.

That I think means that a fair few appliances are likely to be over-run if/when the mains hits 254.4 V, as it can do.

Thanks Guys, I’m satisfied with all that being said.