AS3001 update.

[supersparky]

Of course I've met lots of those type of people T1, I used to work for the council, remember. Unfortunately for myself and our work group, we had to deal with that type of person every day.
I would suggest though, that it would be classified as whatever the reading was on a NATA certified multimeter.
We had to have ours verified every twelve months, otherwise we didn't pass the annual safety inspection.

[jon_d]

Terry, peak is peak.

It's the highest possible point in the voltage measured.
You can have a DC voltage with AC noise superimposed on it. The peak is the top of the signal AC signal. Simple really.


The idea behind it high (peak) voltage that could punch though insulation. Hence the peak requirement, not the average etc.

[T1 Terry]

Terry, peak is peak.

It's the highest possible point in the voltage measured.
You can have a DC voltage with AC noise superimposed on it. The peak is the top of the signal AC signal. Simple really.


The idea behind it high (peak) voltage that could punch though insulation. Hence the peak requirement, not the average etc.

What I'm trying to point out is the 120vdc is ripple free, no peaks, if there are peaks then it isn't ripple free so then the limit is 50vac. They don't care what wave form the AC is, if there is a ripple above X (unknown factor or though 5% is the figure my friend from state rail that writes the what ever it is that becomes the rules for that organisation) then it is not ripple free, so the 50v limit applies ...... The standards mob are brilliant in making things ambiguous so they can not be taken to task over it. The authority that would jump on a loophole only apply the interpretations if an event causing injury or death occurs, after all, they need to cover their shiny buts to justify their existence. If you have ever tried to get a straight from these people, such as the use of an RVD in place of an RCD ..... there no answer to the actual question, just a link to the standards that were written by people who don't know what an RVD is .... along with 90% of electricians ..... Try to get an answer to the question, how do you protect a floating circuit to safeguard against the end user getting an electric shock ...... you will roll your eyes at the reply, if you even get one .....

T1 Terry

[supersparky]

I would say that 90% of licenced electricians have no idea that AS3001 even exists. As for RVD's and how they work, hmm, an even bigger number. Most people only know what they know because that have the need to deal with an issue, but only if they realise there is a potential issue that needs to be dealt with.
As an example, 20 years ago I had no idea about AS 3001, or RVD's, which were only just beginning to be used in the mining industry.

[supersparky]

Further to my above post.

Screenshot_20230628_192023_Chrome.jpg

So the reality is, ripple free is quite possibly non existent except maybe from a really expensive power supply.
I doubt that the man on the street has ready access to one of them.
We may have to wait until someone tests the new standard and see if it brings a change.
Perhaps some definition could be brought regarding the voltage of series connected solar panels.
After the regulator, you would have to try pretty hard to get more than 50v dc
I don't really know what the standard is trying to achieve with a definition like that.

[jon_d]

What I'm trying to point out is the 120vdc is ripple free, no peaks, if there are peaks then it isn't ripple free so then the limit is 50vac.

You can have ripple on a direct current voltage waveform. The peak is the peak. The trough is the trough. But it's not AC. The wave form doesn't cross zero volts and the current doesn't reverse.

As soon as it crosses zero, it becomes AC with a DC component.

[T1 Terry]

Further to my above post.
Screenshot_20230628_192023_Chrome.jpg
So the reality is, ripple free is quite possibly non existent except maybe from a really expensive power supply.
I doubt that the man on the street has ready access to one of them.
We may have to wait until someone tests the new standard and see if it brings a change.
Perhaps some definition could be brought regarding the voltage of series connected solar panels.
After the regulator, you would have to try pretty hard to get more than 50v dc
I don't really know what the standard is trying to achieve with a definition like that.

A 48v system using lead acid batteries would see 2.47vdc x 24 cells = 60vdc in normal cyclic charging and over 66vdc when equalising. A 72v house system, common back when lead acid was all there was available, would be 89v at the end of boost charging and 100vdc when equalising. At the solar side, that would require a lot more than 100vdc to achieve 100vdc with any current supporting it .... questionable if even the 120v limit would give you enough because that 120vdc is open circuit voltage, not Vmp or the point the MPPT controller determined the maximum power could be achieved ..... so a system for that sort of setup could only be carried out by a licenced sparky with no clue about what they were doing ...... but then it would be on an off grid system so the rules do not apply

The question then must be asked, if the RV does not put power back into the grid, is not a fixed supply but rather a transportable premises, just how much clout do the authorities have if the RV is not connected to the grid at the time?
Off grid makes any of this stuff p*ss and wind, the authorities are toothless tigers unless the RV is owned by a company ..... then shitte will get real interesting

T1 Terry

[T1 Terry]

What I'm trying to point out is the 120vdc is ripple free, no peaks, if there are peaks then it isn't ripple free so then the limit is 50vac.

You can have ripple on a direct current voltage waveform. The peak is the peak. The trough is the trough. But it's not AC. The wave form doesn't cross zero volts and the current doesn't reverse.

As soon as it crosses zero, it becomes AC with a DC component.

What is your definition of ripple free Jon? Would it hold up in a court of law with a QC challenging it?
I'm guessing the authorities themselves can't answer that one so they simply say "ripple free" to throw a blanket over the whole thing.

T1 Terry

[jon_d]

AC = Alternating current.

DC = Direct current.

Is a sine wave signal on the collector of a transitor AC? No. It's DC with a varying current Put a capacitor in circuit and isolate it from the DC such that it crosses 0 volts and then it becomes AC .


Ripple is not AC. AC (alternating current) by definition is only AC when the current reverses. It doesn't reverse until it crosses below 0 volts.

The thing is, people will put a DC meter on a wire and measure 100V. It could be a pure 100VDC (which is like saying 100V DC Average RMS) or is could be

70DC with a 30V RMS sine wave superimposed on it. A DC meter will still read 100VDC Average RMS. It will flutter around depending on its reponse time. A CRO with a fast response time will show the signal. However (from memory) the peak is 70 + Root 30/2.

But is not AC and not ripple. Because the sine wave was actually a speaker signal, centered around 70VDC.


To your point,

I'm guessing the authorities themselves can't answer that one so they simply say "ripple free" to throw a blanket over the whole thing.

Maybe their terminology is wrong. And they should simply it for the laypeople by saying removing ripple from the vernacular and simple refer to maximum peak voltage not crossing the zero volt line.

[supersparky]

Maybe, after I get my hands on a copy of the new AS3001, I could ask the ESO Qld for a definition of what they consider to be ripple free dc.
At the end of the day, we all know that the previous standard was way out of date and had little or no relevance to how RV Solar systems had evolved. If you were to go back a few years a transportable structures was a portable site shed, temporarily connected to the grid.