Beiträge von barry2002

Already thanks for the updates...

so we can see they use opto couplers ... so input & output is isolated.

That's already good news...
I will think about my next step ... smd soldering ... or put a relay in front.

Doesa anybody know reason why the shelly 4 pro inputs are only Vac (110-230V),

Vuc (8-230V ac or dc) would be more convenient as a lot of electrical installation are done with buttons that can only carry 24V.

I would like to try following setup ... but I don't know how isolated the inputs are from the ouputs.

Does anybody know ?

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I think we should investigate the 2 watt meter method ... I think this could work.

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Basically ... you take one of the wires and use as "neutral" ... so we actually don't need the 3rd input

I think you are correct... we indeed need to know the linevoltage (Lx to N) not the phasevoltage,

in order to have correct calculations.

For now i made a program to capture the values of the current and voltage every second.

This way i have at least some idea of the power consumption.

If you do star-star .. I think I will need to find a transformer with ratio 1:1.73 ... else the voltage will be not correct... i don't know that exists...

I think a Delta-Star transformer will not be the solution.
If I remember correct when using 1:1 transformer in delta-star configuration there will be a phase shift of 30° between primary & secondary.. resulting again in a bad powerfactor at measuring side of 3EM.

So i tried ... powering the 3em in a one phase way...

but then the powerfactor (phase) is not correct.

So if we would be able to manually adapt/adjust/offset the phase we could get it to work in some way.

Is there a way to get the voltage & current history ... because this is always correct?

Dear,

i hope somebody knows...
In belgium we have some electrical networks that don't supply a Neutral to the home.

So the network is 3x230V i.s.o 3x400+N ....

The shelly 3EM requires a N to be supplied ... probably to measure the voltage per phase.

Is it possible to power the 3EM without neutral ?
Worst case i need to wire it up as 1 phase... but then the information of voltage per phase will be lost so the wattage will be slightly of.
Or does the 3EM measure the phase between voltage and current ? if yes... it's unusable.

thnx...