[Solved] Safety Concerns: Mounting Foam on Electrical Switchboard Cables

Please help,

The cables in the electrical switchboard of the apartment that I received from the developer are dirty with mounting foam - I attach photos.
Can such contamination of cables cause problems (load, voltage) and can it be dangerous?

I learned about the condition of the interior of this switchboard only after a problem with the installation occurred - I heard sparking, there was a problem with the voltage - as a result, one fuse was melted - it needed to be replaced.

The foam itself is an insulator and has no effect on the installation. On the other hand, it looks terribly ugly.

Kraniec_Internetów wrote:

And this foam burns very nicely.

Just like the supposedly "non-flammable" insulation of wires.

But the foam also got on the N and PE strips and may cause insufficient contact between the wires because it is an insulator...

panjann wrote:

I learned about the condition of the interior of this switchboard only after a problem with the installation occurred - I heard sparking, there was a problem with the voltage - as a result, one fuse was melted - it needed to be replaced.

But it`s probably not the foam but a loose connection.

Under what circumstances can the camera housing melt? Is it a matter of a loose contact on the outflow side and when a load appears on the circuit, heat is released from such a loose contact?

takijasiu wrote:

Is it a matter of a loose contact on the outflow side and when a load appears on the circuit, heat is released from such a loose contact?

Yes, of course on the inflow side the situation is identical.

Moreover, the switchgear was made incorrectly and the switch was used. 3-phase residual current circuit for single-phase circuits. There is a greater threat to equipment than foam, and sloppiness of installation in development construction continues. No one even protected the switchboards against being damaged by soil before plastering.

andrzej lukaszewicz wrote:

used off 3-phase residual current circuit for single-phase circuits. There is a greater threat to devices than foam here

Could you explain to your friend why there is a threat to devices?

It has been written dozens of times on this forum. Zero disconnection in four-pole devices. That is, what will happen if the N track is damaged or switches on with a delay in relation to L1 L2 L3.

andrzej lukaszewicz wrote:

It has been written dozens of times on this forum. Zero disconnection in four-pole devices. That is, what will happen if the N track is damaged or switches on with a delay in relation to L1 L2 L3.

So a 3-phase RCD with a marked N circuit and a 1-phase RCD with a marked N circuit behave differently? I.e. on a 3-phase RCD, the order of switching on the individual wires is generally random, but in a 1-phase RCD, are the two wires there switched on in the right order?

Moreover, if behind the 3-phase RCD there is, for example, 1 3-phase receiver and several 1-phase receivers (as the photo shows, the first device is a 3-phase 3P overcurrent circuit breaker), what does it matter for two 1-phase receivers? does it mean that the power will appear on one of them 5 ms later than on the other?

And it has also been written so many times that this is a cheaper solution, because the "developer" wants to make money quickly and have peace of mind with the loans he took out to build a house. And since this solution also poses a danger - who cares?
When push comes to shove, it`s not the investor who will go to jail, but the person who received the installation.

Added after 1 [minute]:

takijasiu wrote:

andrzej lukaszewicz wrote:

It has been written dozens of times on this forum. Zero disconnection in four-pole devices. That is, what will happen if the N track is damaged or switches on with a delay in relation to L1 L2 L3.

So a 3-phase RCD with a marked N circuit and a 1-phase RCD with a marked N circuit behave differently? I.e. on a 3-phase RCD, the order of switching on the individual wires is generally random, but in a 1-phase RCD, are the two wires there switched on in the right order?

Moreover, if behind the 3-phase RCD there is, for example, 1 3-phase receiver and several 1-phase receivers (as the photo shows, the first device is a 3-phase 3P overcurrent circuit breaker), what does it matter for two 1-phase receivers? does it mean that the power will appear on one of them 5 ms later than on the other?

Does your friend know what it means to have no zero even for 5ms?

clubber84 wrote:

Does your friend know what it means to have no zero even for 5ms?

Sorry buddy, but the question I asked was completely different. So maybe I`ll ask again: does RCD 1-f properly support the N track, and does RCD 3-f support the N track incorrectly?

takijasiu wrote:

RCD 1-f serves the N track correctly and RCD 3-f serves the N track incorrectly?

Both operate correctly in the circuits for which they were designed (i.e. three-phase and single-phase). A 3-phase RCD may be dangerous for single-phase circuits, read about N loss.

In the absence of N in a 2-pole device, there will be no problems other than the lack of operation of the circuit.
In a 3-phase, 4-pole device supplying single-phase circuits, the lack of N is a serious problem with accidental voltage division of two receivers connected in series at 400V.
And if it`s an iron and a charger, we know how it will end.

ArturAVS wrote:

takijasiu wrote:

RCD 1-f serves the N track correctly and RCD 3-f serves the N track incorrectly?

Both operate correctly in the circuits for which they were designed (i.e. three-phase and single-phase). A 3-phase RCD may be dangerous for single-phase circuits, read about N loss.

Therefore, RCD 3-f is 3P + N and RCD 1-f is 1P + N, i.e. the N circuit is always switched on before the phase connections and always disconnected after the phase connections. So why can connecting 1-ph receivers to the RCD 3-f phase terminals cause them to have a phase wire connected before the neutral? Since both cameras support N properly?

Read post #16.

andrzej lukaszewicz wrote:

In the absence of N in a 2-pole device, there will be no problems other than the failure of the circuit to function.
In a 3-phase, 4-pole device supplying single-phase circuits, the lack of N is a serious problem with accidental voltage division of two receivers connected in series at 400V.
And if it`s an iron and a charger, we know how it will end.

Can you explain what 2 receivers connected in series at 400V are?

There are 2 LN circuits, they are L1`-N` and L2`-N` - where N` is N after the 3f 4P differential, and L1` is L1 after the differential and L2`, respectively, is L2 after the differential.

A given particular receiver has the L and N wires connected. The L1`, L2` and N` wires - let`s assume - can be connected inside the differential switch with the L1, L2 and N wires, respectively, in a random order.

I still don`t understand, where is the place for 400V? Tracks L1-L1` and L2-L2` are not normally shorted to each other in the middle of the differential. And the receivers are connected between the wires L1` and N` (the first receiver) and the wires L2` and N` (the second receiver).

Edit:

Okay, I think I understand: the receivers are connected by a common N`, which, until N` is connected to N, will be a wire connecting only the receivers and this will effectively close the L1`-L2` circuit through two receivers and the N` wire between them?

However, if RCD 3-f operates as 3P+N, it guarantees that the N`-N connection in the differential will be switched on first - right?

takijasiu wrote:

However, if RCD 3-f operates as 3P+N, it guarantees that the N`-N connection in the differential will be switched on first - right?

And what if it gets "hot"? Or will the clamp be loose as described in #1?

Yes, in RCD 3f you are guaranteed to disconnect the N terminals last. There is no randomness here. If it were otherwise, the TEST button would be a form of Russian roulette for, for example, two-phase induction hobs.

Manufacturers even provide turn-off times and differences between Lx and N in data sheets. You can check the order by performing an experiment: the lower terminals of the RCD device to the ground of the 12V DC source, and the 4 12V indicators to the upper terminals. By slowly moving the lever down you will see the lights go off in a specific order, the one connected via the N track will go off last.

Some devices, e.g. a computer (with a switching power supply, protection class I) have a certain leakage. If only one RCD device is used for the entire facility, it is possible that the "collected" from all devices will exceed the response current of 30mA. If the RCD trips, it may not be clear where to look for the problem in the installation. The use of several RCDs "narrows" our search.

ArturAVS wrote:

takijasiu wrote:

However, if RCD 3-f operates as 3P+N, it guarantees that the N`-N connection in the differential will be switched on first - right?

And what if it gets "hot"? Or will the clamp be loose as described in #1?

Of course, yes - if it gets hot or unscrews, this will also happen.

How often does it happen that a break in the N track behind the 4P or 3P+N device causes the circuit between the phases to close (i.e. a floating zero is created) and the result is a fire? I`m asking not maliciously, just out of curiosity, how often does this situation happen? If such a situation occurs, will the insurance company not pay compensation and prove that the installation was performed incorrectly?

takijasiu wrote:

the result is a fire

This is a drastic case, but possible. Most often, some devices are simply damaged (sometimes the damage is significant), and I have personally encountered such damage.

This break behind the RCD can basically only occur in the switchgear. If everything is done correctly (cross-sections, tightened clamps), such a situation should not arise.

Much more often there is a PEN break, a "zero" before the counter.

popiol667 wrote:

This break behind the RCD can basically only occur in the switchgear. If everything is done correctly (cross-sections, tightened clamps), such a situation should not arise.

Much more often there is a PEN break, a "zero" before the counter.

In general, any situation when receivers powered from different phases are connected with a common N wire is dangerous, because if this common N wire is interrupted in such a way that it loses continuity to the place with the lowest potential (e.g. in the TN-S system to the point of entry N wire "to the building"), this N wire will close the circuit between the phases.

But then, is it normal to ensure that all single-phase receivers powered from phases L1, L2, L3, respectively, have neutral wires collected, e.g. on terminal strips for L1, L2 and L3, respectively, in such a way that the most object, the connection point of these N wires were their terminal strips in the switchboard? This would actually be a guarantee that a break in any N wire anywhere outside the switchboard would not result in a closed circuit between the phases. I`m sorry if the answer to this question is obvious, but I just don`t know.

Generally speaking, it is not so much what is sought, but rather what it is in a typical installation. A break in the N circuit will not "close the circuit between the phases" - unless it is a 3-phase circuit, e.g. for a stove (e.g. you damage the blue wire in it).

takijasiu wrote:

How often does it happen that a break in the N track behind the 4P or 3P+N device causes the circuit between the phases to close (i.e. a floating zero is created) and the result is a fire? I`m asking not maliciously, just out of curiosity, how often does this situation happen? If such a situation occurs, will the insurance company not pay compensation and prove that the installation was performed incorrectly?

As I understand it, according to you, if he burns a charger once in ten, a TV set for five PLN one in a hundred, and if he kills someone once in a thousand, he will still get away with it? And PZU will pay the money anyway. Maybe not for a charger, but for a TV, yes, and you`ll buy a new one; and for your skin your wife will get...
Interesting...
When I read new standards and regulations and see new types of security, I can say that someone is making a lot of money...
But what if it turns out that at this critical moment it will protect your charger, maybe your TV or YOUR life? Will you still ask about numbers?

Andrzej42, what is wrong with asking about numbers? A colleague of mine asked a technical question. You are suggesting that he is cunning. This is probably not entirely consistent with the rules of this forum.

The smart guy is not the user who asks if there is any threat, but the one who did something like that and the one who received it.

Will it matter whether there are 3xRCD 1f or 1xRCD 3f if an interruption in the N or PEN track occurs before the switchgear?

You can also write that new regulations and security measures are being created, and a fussy electrician will still cover everything with foam.

As for the answers:

popiol667 wrote:

You`re suggesting he`s cunning

if so, lack of knowledge or experience,

andrzej lukaszewicz wrote:

Moreover, the switchgear was made incorrectly and the switch was used. 3-phase residual current circuit for single-phase circuits.

This was already stated in post #9, so why bring it up in the next ten posts

popiol667 wrote:

and what is wrong with asking about numbers?

nothing, but why? No, I understand: According to statistics, flying by plane is many times safer than driving a car, and yet we get into a car every day and no one cares about the numbers.
And here: the user of the installation asked a question and we answer him and give him suggestions. And then there are questions: why, too much, you can do it cheaper, how many times - I know, some people know better - we can`t help it, but we try to explain to others: the four-pole residual current circuit breaker is used in three-phase circuits, it is not recommended for single-phase receivers . Especially since it`s not all that expensive anymore, it can be planned and done reasonably well.

I will add, quite off-topic, that when differentials began to be introduced, people installed only one for the entire house.
During the initial conversations, I always suggested including a few, because let`s imagine it`s New Year`s Eve, a party in full swing, a cheerful guy enters the bathroom, pours water on the washing machine or whatever, and... the party continues with candlelight and a guitar.

1. The user does not need to have any knowledge, that is why he is asking
2. I`m asking without malice - if it was made incorrectly, why do these types of flowers pass through during designs and acceptance?
3. I don`t think anyone in this thread has written that it can be cheaper. Questions about why they are so expensive arise because people see switchboards with one RCD for the entire house/apartment, and some electricians will say that this is enough.
4. I fully agree that one camera is not enough. The situation is half the problem, as described in the description, what to do when you don`t know where the fault occurred, which causes the RCD to trip, but does not trigger the operation of other protection devices.