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MPP HV2-5048 Earthing of output

Bob Steel

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I have this inverter on a 48v battery and producing 240 volts A/C.
Its wired up normally as is the 240v A/c output but I ran the output through a RCD first then to the outlet plug . All the earths are connected together BUT I have not yet connected them to the main earth ground peg .

Before doing so I turned the inverter on and measured the A/C voltage from the unconnected earth to earth proper and found it had a 48v A/c potential.

Is this correct? Is it how it should show at this time ?
Or is that telling me something is amiss.?
 
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Your talk of 240v suggest your not in the US? Location here is important as different regions of the world have different wiring standards.
 
Well I'm finding out for myself . This site is becoming a bit un-usable with silly posts .
Its looking like a MEN system is needed (Multiple Earth Network) and I will have to link my Neutral wire to earth . If anyone has any comments on the MEN system please add them . I saw a post somewhere that this was a bad thing in the event of lightening strikes as the difference in voltages just 10 feet away can cause massive current flows.
 

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Well I'm finding out for myself . This site is becoming a bit un-usable with silly posts .
@Bob Steel (aka Ty Tower) please explain.

Where the output voltage should not have influence the "strange" voltage readings you have, it's not a silly question.

240v "not North South America" systems NEVER have the neutral grounded.
That's USA 120v style.

Even making the suggestion to ground th neutral line makes clear you do not have the basic knowledge and skills yet to do installations on your own.
Please let a senior electrician guide you before accidents happen.

The 48v readings you get.
Yes, I have had the same, and it was bugging me nuts.
No falce contacts, all clean and properly installed.
Solution is simple and probably in the manual.
Ground the inverter/ hybrid.
It's power in and out have 3 wires.. one yellow green. (Earth/ground)
Connect it to your grounding rod and your problem disappears.

But what is this??
Best guess, leaking current.

In the aeva forums where you asked the same question, they call it ghosting voltage and that you should not worry about it.

That's absolutely WRONG advice!!
You should ground your hybrid inverter, as without it that 48v can give you a nasty bite, people with pacemaker can get huge trouble from this bite. (Aka electric shock)

You probably don't have one, and don't know anyone who might have one that could possibly want to come and help you with the installation.... Still... If that friendly neighbour steps in after hearing your complaints and he does get ...
That's on you.

Always ground your equipment!

The MPP HV2-5048 is low cost hybrid inverter. While perfect functional it will have higher own power consumption (+100w) and some "challenges" that a triple the price Victron or Outback type won't have.
One of them is leaking current/voltage.

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Lighting rods (different use for the "same" grounding rod) are not to be used in a grounding MAN system.

Most ideal the lightning rods (almost always connected with eachother) are 10 meters away from grounding rod.

Real life that's hard to do, and a few meters distance can be happening.

While lighting strikes in the lighting rods will have usually no effect on the grounding, it might have when they are too close to lightning rod.

For me I have 4 meters between them.
After a few hundred strikes, not a problem for my (off grid) house.

Not grounding things..
That can give strange results.
 
Well I think you make sense , then reading a bit further I lost it , then it came back and now I don't know if you have the faintest . Guess I need some of what you're on to even things out a bit. If someone repeated my post somewhere its because we are in a group discussion on this .

For me I have 4 meters between them.
After a few hundred strikes, not a problem for my (off grid) house.
That's a lot of strikes in one spot but there is much discussion and conflict on that point as you may be aware .
Don't judge my abilities by some pre-conceived notion you may have .
I ask because I want to be certain and opinions from people who have done it and have experience is worth heeding.

Solution is simple and probably in the manual.
Ground the inverter/ hybrid.
The Inverter IS grounded to the common ground on all devices . This A/c voltage is between that wire earth network and real ground rod. (They are not yet connected as I did this check before I connect it all up.I thought I had made that very clear but not clear enough for you it seems.)

The MPP HV2-5048 is low cost hybrid inverter. While perfect functional it will have higher own power consumption (+100w)
No it doesn't actually, its half of that , 48 watts to be exact and I think a good bit of that is on fans .So it has a constant draw of 1 Amp on the 48 v battery.
What is the draw on Victron or Outback?
Lighting rods (different use for the "same" grounding rod) are not to be used in a grounding MAN system.
Oh and its the "MEN" system and I suspect you are trying to get a point across with this line but I don't understand . Want to try again? How did you handle the few hundred strikes mentioned above?
 
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It's good that you have a group to discuss the issues, besides getting input from forums.

I was a bit p!seed due your second post, telling @schmism he make silly post....

That's not a good way to make friends as it wasn't really silly ..
Enough about that, and sorry if I bashed a bit back..

Victron and outback seem to have 15-25 watts own power consumption.

My Revo II (hybrid inverter) is about 50-75 watts.
It fluctuate and I haven't installed the shunt yet to make accurate readings.

For me the additional price in the high end brands is just too much compared to what they bring, compared to middle class like MPP, Sorotec, EPEver, Etc.

Low class like EASun... Stay away ?

I didn't understood that you did have it grounded yet.
That's good that you did!

(At the start I forgot and had some strange experience with it.., re-reading the manual and search on Google about off grid and grounding opened my eyes :) )
(I'm really good at making mistakes)

I wasn't aware of the special requirements that are needed for off grid grounding.
Basically you need to do a whole lot better then normal homes.
Got that covered now :)


Yes, during rain season we have a lot of thunder, and our location apparently makes it really Optimal for lighting.

I haven't counted them all, but 3 or 4 strikes during thunder storms is "normal" (I know that's high. We are on a hill)

Our lighting rod is the highest point for 100 meter (?) Radius.
(Probably more)

Last 2.5 years since it's up probably a few hundred hits.

Yes, there is many discussions about effects of lighting strikes and home electronics.
I'm just writing what works for me.
(And really happy it does!!)

Not native English, man / men easy for me to mix up.
Even when it acronym :)

Probably dumb to mention it, but I did see a lot of people using their lightning protection to ground their equipment.

As long as there is not a hit....
Sure, why shove an other rod in the soil?

When there is a hit..
You are screwed.

I wish I was making it up.
Then again.. Thailand.. everything goes :)
images (64).jpeg

Standing on a ladder made of Bamboo, official crew equipment :)
 
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Ps.. 1A on 48v is huge..

I have 48v delta fans.
0.75A and one fan is enough to cool 2500 watt ASIC miner...
And LOUD!..
Most hybrid inverter have 2* 12v 80mm fans with max 0.35A draw, that's about 8-9 watts
 

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It's good that you have a group to discuss the issues, besides getting input from forums.

I was a bit p!seed due your second post, telling @schmism he make silly post....
I watch these exchanges in forums. It's weird as some licenced electricians are terrible communicators, others will upsell and overspec at every opportunity. Then there are legitimate questions by owners questioning installs left by electricians which are obviously dodgy.

somewhere in the middle it should be possible to civilly exchange how to recognise a good/bad design and installation.
 
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