How to detect Line (Hot) and Neutral Reversed with the electronic circuit? #2

Thread Starter

juri.burg

Joined Nov 14, 2021
1
I have the same question.

In my case i want to use a Victron Inverterchager (MultiPlus-II 48 | 5000) in an RV, Single phase only.
The Manual States "Do not invert neutral and phase when connecting the AC."

The problem is that most country's around here use Schuko connector for 230V AC. with this connector can be inserted 2 ways around, alternating the phase and neutral pin.

I am thinking about using a to witch phase and neutral, feeding the coil with neutral and ground (connected before the relay).
This way if phase and neutral are correct the relay does not get power, but it the are inverted the relay will invert them once more.
The only problem i can think of with this solution is that the coil in the relay will trip the RCD of the camp side. Any solution?
 

crutschow

Joined Mar 14, 2008
29,466
the coil in the relay will trip the RCD of the camp side. Any solution?
You will need a detection circuit that will draw less than that which would trip the RCD.
You could use a low current solid-state-relay (SSR) such as this, which only requires a few mA to operate, to control a larger mechanical relay operating from the mains.
The SSR will require a diode, series resistor, and filter capacitor, along with another resistor in series, to provide the DC LED input control signal.
 

MisterBill2

Joined Jan 23, 2018
11,573
One fail-proof option is an isolation transformer. Heavy and expensive but reliable.
I have the same question.

In my case i want to use a Victron Inverterchager (MultiPlus-II 48 | 5000) in an RV, Single phase only.
The Manual States "Do not invert neutral and phase when connecting the AC."

The problem is that most country's around here use Schuko connector for 230V AC. with this connector can be inserted 2 ways around, alternating the phase and neutral pin.

I am thinking about using a to witch phase and neutral, feeding the coil with neutral and ground (connected before the relay).
This way if phase and neutral are correct the relay does not get power, but it the are inverted the relay will invert them once more.
The only problem i can think of with this solution is that the coil in the relay will trip the RCD of the camp side. Any solution?
Is there any mention of the reason for not exchanging the neutral and power phases? If it will cause damage that is one thing, but if it leaves the system unsafe that is a different situation. Rather than trust an automated system that will consume power constantly it seems more reasonable to have a way to know which side is the line and which is the neutral. And I can not imagine that a GFCI for the whole RV would ever be workable, as the total system leakage would always exceed the trip-off limit, even though no device had an unsafe leakage level. Depending on a "Ground" reference does not seem at all dependable if there is not a ground as part of the mains connection. And in a 2-circuit connector there will never be that third connection, I don't think.
Two neon bulbs, such as the "NE2", with one lead to each side of the power connector and the other lead to a touch plate could give a rather reliable indication, but the correction would have to be manual.
 
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