Hi All,
Newbie to the Forum.
I have an install with a Multi RS Solar (twin MPPT version) that is running my ‘off grid’ setup.
We have the ability to grid tie and I’m looking at it for winter (UK based) and for Conditional relay opening for the AC Input - load or battery SOC.
I’ve been doing some testing before I connect to the grid and have c.15v on the AC Input connections (between line / neutral and earth) on the RS no matter the relay state - is this normal? Am I missing something in the settings that would cause this?
If this connects to my supply from the consumer unit, it will cause the RCD to trip.
Thanks in advance.
Even if the AC-IN relay is opened, the Multi RS is still sampling, with its electronics, the AC-IN, for showing you the voltage there.
So you are saying that when the Multi RS is functioning, with the AC-In terminals “in air”, you can measure that voltage?
If this is the case this is strange and must be something wrong there…
Sorry, English not my first language, so I don’t really understand: the RCD tripping is a fact or a supposition?
Thanks for response, Alex.
Yes, I have measured the voltage at the AC-In terminals on the Multi, nothing is connected to the grid.
I know that it will trip the RCD (I have electrician background), but I have not connected so not a fact in that way.
My assumption was that it must be a setting that I’m not doing correctly.
You’ve used, for sure, a digital voltmeter.
Those devices have a very high input impedance and can be influenced very easy in their measurements.
Just make an experiment and put a 10K resistor in parallel with the DMM input and measure it again.
Why 10K? Because 10K at 230Vac will give you those 30mA that will trip a normal RCD.
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Yes, using my Fluke 1662 Tester.
Yes, I believe all is OK.
Just use that resistor when measuring and you’ll see.
Those 15V are coming / leaking from the low voltage electronics I’ve mentioned, who are measuring the Multi RS input voltage.
Okay, I’ll have a look at it tomorrow.
Thanks again.