Residual current device in the TN-C photovoltaic installation

Question

Hello, I came across several installation diagrams of photovoltaic power plants, each with a 4P 40A / 300mA Type B residual current circuit breaker (for example from the HAGER brand). The only strange thing is that the selected diagrams worked in the TN-C system, which made it practically...

zbich70 · Answer

List these diagrams, especially their sources.

Anonymous · Answer

There is a ban on the use of RCDs on TN-C. And this designer can't go wrong?

eclipse99 · Answer

Schemat:

Anonymous · Answer

Is 5x16mm2 or 5x35mm2 a TN-C network?

BILGO · Answer

Why do you think so ?

masonry · Answer

Why do you say it's TN-C? After all, the RCD is inserted on the DC side.

eclipse99 · Answer

I was simply at the site of a potential investment and I noticed that PE + N are connected together in the main switchboard ..... hence my supposition that the designer did not read the documentation :-)

I was also wondering why these differentials are so expensive ... even 3,000 PLN!

jacur · Answer

Rather between the inverter and the produced energy meter And this RCD protects the inverter anyway?

BILGO · Answer

Certainly, these RCDs do not protect the Inverters. PV inverters have enough built-in safeguards ... I wonder why they cost 3,000 Could you please provide a model?

eclipse99 · Answer

Such differences are located between the inverter and the meter of produced energy. I gave the link to the RCD earlier.

Anonymous · Answer

After the topic post, I read the texts on photovoltaics.

In my opinion, photovoltaics should be a department in installations.
Photovoltaics cannot be considered in isolation from electrical installations.
It's like ophthalmologists or ...... mechanics discussing dermatology.
It is impossible to argue about photovoltaics without thorough knowledge of this department.

eclipse99 wrote:
I gave the link to the RCD earlier.

I watched this link about the RCD. - out of curiosity. RCd like RCd nothing special.
Security - you need to define what you are protecting against.
Or specific what - what device requires protection.
There is no panacea for everything in security.

Anonymous · Answer

It is certainly not a TN-C installation. Rather, it is the contractor who has not read the documentation. What is you? The word thousand does not contain ś. It is a special residual current device designed for circuits powered by inverters (or other power electronic converters).

jacur · Answer

Then there should be an RCD of type B behind each inverter? It is probably the opposite. RCD type B It is used to protect the power supply circuits of inverters. There is something about that in this pdf page 22:

Anonymous · Answer

Jacur , it is not a bit the other way around, nor very vice versa. Read carefully and understand the text from your link. Read on to page 24, there is a schematic and you can see exactly where the RCD is mounted.

jacur · Answer

Mostly, this type of RCD was installed on the power supply of inverters. But maybe because of the price it is not very popular and you need to increase sales just as you might imagine.

but I like "just in case" p.23

- technical instructions VdS 3145 - "Photovoltaic installations" - recommended ("for all
accident"

according to 4.4.4.3 the use of circuit breakers for protection against fire
RCD;

BILGO · Answer

In my opinion, the use of RCD type B for PV inverter type inverters does not make sense. Of course, RCD can be used, but AC type is sufficient.

Anonymous · Answer

I wrote precisely in post # 12
What and what to protect against.

jacur wrote:
It is probably the opposite. RCD type B It is used to protect the power supply circuits of inverters.

What is this supply circuit inverter?
What do we protect the inverter's power supply circuit against?
What can an RCD protect against at all - object of protection = circuit?
Is precision and logic in thinking too high a bar?
Using general and poorly formulated concepts is impossible to communicate.

arelektroda · Answer

Can someone explain the difference in the diagram in post # 4 and in the descriptions. E.g. My point is to clarify whether the rated differential current should be 30 or 300 mA because it is such a small difference.

Anonymous · Answer

Never heard about it. Why should a three-phase RCD be installed on direct current? Moreover, this RCD protects against the effects of damage to the insulation of the receiving installation or the effects of damage to the insulation of the receivers connected to this receiving installation. An RCD installed on the supply side of the inverters would not trip.

BILGO · Answer

At the beginning of the argument, gentlemen, decide which inverter is concerned, whether it is an inverter - a PV inverter, or an inverter - a frequency converter.
From what I understood my friend Jacur wrote about an inverter - a frequency converter

Anonymous · Answer

There is nothing to determine, just read the topic of the thread. The thread has nothing to do with the frequency converter. In addition, the supply of (all) inverters is DC voltage, which results from the definition of the inverter.

Wirnick · Answer

I want to note that the RCD is at the installation site 3x230V 50Hz. It does not matter what is the front or before (it checks itself - whether there is current asymmetry) - it checks the condition of the installation in both directions - in the current receiving phase or in the voltage generation phase. The type of RCD depends on the harmonics of the current.

Anonymous · Answer

This is exactly the logic of my colleague Wójcik. Someone with little cleverness has stuck the RCD overzealously as panacea - it is not known for what. Simple and logical what is the RCD for! The RCD measures the difference of the L and N currents. Nothing else measures. There, overcurrent protection is needed against the effects of damage. Why such a strange parameter 30mA? The 30mA AC current is the limit current that does not kill a person. It's about alternating current - a person withstands direct current more. A medical parameter that has nothing to do with the receiver and the network. The 30mA RCD is designed to protect people - not devices. It is to prevent people from being killed in the event of an electric shock. Only 1mA leakage disqualifies the device - the device is inoperative. RCD 300mA in general is assumed as fire protection of the electrical installation. Someone made it up.

Wirnick · Answer

Looking at the figure below, those using renewable and traditional energy are deprived of the protection of second-lieutenants. despite the use of an RCD in the inverter.

Anonymous · Answer

Why ? What's the difference with what powers the RG? Security is still in place in the facility installation at RG. RG pictorial drawing, without details.

Wirnick · Answer

Mr. Bronek, I will present a very detailed drawing now. Represents 100% basic protection of the user - only the inscription is available. Still, the RCD is not allowed to function properly.

Anonymous · Answer

They have protection in installation in a switchboard. They are not without protection. I have not written a word about this RCD - what it is for.

Anonymous · Answer

And how did your colleague know that 3 × 230V? I can see 400 / 230V, i.e. phase-to-phase 3 × 400V. I also do not know why the RCD would malfunction?

Anonymous · Answer

Since when is the RCD basic protection - and 100% of the user more = any alternative rules? This is how long a colleague is on the forum ......

Residual current device in the TN-C photovoltaic installation

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