Wiring Unlimited - floating network page 62

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daan-de-willigen asked 5 days ago

Wiring Unlimited - floating network page 62

Hi,

Ive searched the forum but could not find this question asked.

In Wiring Unlimited (rev 01 - 03/2023) chapter 7.5, about mobile IT Networks page 61/page 62.

It states that IT Networks are not connected to ground (therefore have a floating neutral) but in the images to this subject, in the middle image there is a connection between source and ground.

it proceeds to say no current will flow. But if i'm not mistaken, current will flow through body, through ground to source if there is such a connection als shown?

Thank you in advance, and if this already asked on this forum please redirect me to the topic.

wiring wiring diagram float

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sharpener answered · 4 days ago

Yes, the middle picture in the top row of p. 62 and the first (l.h.) picture in the second row appear to have been transposed. Maybe @Guy Stewart (Victron Community Manager) can feed this back?

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Guy Stewart (Victron Community Manager) ♦♦ commented · 4 days ago

Thanks, I’ll pass on the feedback to the author.

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daan-de-willigen commented · 4 days ago

Yes, that is it. Thank you for pointing that out.

I think it should indeed be fixed. People use these images as installation diagrams.

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Answer 1 · 2024-07-10T14:45:17Z

Alex Pescaru answered · 5 days ago

It's a ground/neutral loop, not a power loop, so no problem / danger there.

Danger will be if the human touches the brown / fused wire.

Maybe my terms are not very well used, sorry, not an English speaker.

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daan-de-willigen commented · 4 days ago

Thank you for your reply.

An IT network does not have a neutral-ground bond if im not mistaken. So that would be incorrect in referred image.

I understood that to create a 230v potential using an inverter with floating neutral, both neutral and live carry 115V. This would mean the neutral in this image would be harmful if such a ground connection exists in an IT network, correct?

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Alex Pescaru daan-de-willigen commented · 4 days ago

Hope we are talking here about single phase things and not split phase things, right?

Any power source will have (at least) 2 wires/terminals. The idea is that somehow both those wires to touch the human body in order for the circuit to close and the current to flow.

A floating power source (with neither terminal connected to earth) will have 0V potential between any of the terminals and earth. But it will have full voltage between its terminals, because between its terminals the power is generated.

When you ground (verb) any of its terminals, that terminal will be brought to the same potential as the grounding point and that point can be considered as a voltage reference.

In your circled image, both the leg and the arm have the same potential (earth and neutral, because they are connected together) and therefore no current will flow.

Keeping this in mind, take a look at the pictures and where you will see that both Phase and Neutral touch, through any means, the human body, that is a danger situation.

I am saying "any means", because the Earth (the planet / the big blue marble we are sitting on / etc) can be considered a continuous wire between any two physical grounding/earthing points on this planet.

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daan-de-willigen Alex Pescaru commented · 4 days ago

Thank you for your extensive reply and time!

I think because of the mobile IT network structure this picture is referring to, the source is in most cases an inverter or generator, it has no earth reference if im not mistaken, and i read that live and neutral both carry 115V. Sorry for not stating that.

Edit: to be clear, my point here is that the picture is not correct for the situation described in the chapter. I do not doubt the logic of the picture itself, just in the situation it is referring to.

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