question

urs4-2008 avatar image
urs4-2008 asked

Input RCD trips when 3 phase Multi's have neutral connected on output - not without

New install. Earth fault triggers before the Multis (that are in 3P) when Neutral are connected on the output - but not if they are not connected. Nothing is connected to AC out, except a RCD breaker (that doesn't trip). I believed the transfer relay connected neutral in with neutral out?

Changing the breaker before to one without ground fault then everything seems OK. And if neutral on the output are not connected together in a ac out breaker, then also everything works fine.

Could it be that one of the new Multis introduce a ground fault themself? Nothing else is connected, other than AC IN and a breaker on AC out1.

Multiplus-IIESS3 phase
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1 Answer
Michelle Konzack avatar image
Michelle Konzack answered ·

I think, we beed more infos.


However, if you are Off-the-Grid, then the common N from the Inverterd should be grounded.


From there you with the three L and N to the RCD and from the RCD to the Fusebox.


In the Fusebox you EART the PE and the rest of the installation is as usual.


This should not trip the RCD (at least not here in my Place) and I use an ABB/Metrawatt device to test the RCD with 0-1000mA to see, if my installations are correct.

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