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Testing RCD: Methods to Check Residual Current Circuit Breaker After Heater Electrocution Incident

mis_dj 73765 17
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Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
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  • #1 4171253
    mis_dj
    Level 12  
    I am asking if there is still any method of checking the residual current circuit breaker. Recently, I have a problem that when connecting the heater, I accidentally touched the power cord and was electrocuted (luckily I was gently caressed) at home I have a new installation (new house) before everything was fine, ie the switch went off when the electricity ran out. I checked the switch with "T" TEST and the first time it broke (inside, however, something sparkled slightly), however, after turning it on again and trying to "TEST", the switch does not strike me anymore. I also checked by shorting the phase wire with the pin and it did not knock out either. Is there any other way to check if it is scrap? I will add that I am not an electrician and I am asking for a simple advice because I do not know the terminology of electrical strikes.
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  • #2 4171279
    pawka_pk
    Level 22  
    As it does not respond to the test, it is damaged, especially when you shorted the phase wire on the pin. Nothing to risk. Better replace it.
  • #3 4172560
    Jekaterina
    Level 12  
    The RCD will trip when current flows between N and PE. Shorting L and N does not switch off the differential, but only damages it. Checking the differential consists in shorting the wires: N and iPE (at home, of course). There are meters to check RCDs, and if the test doesn't work for you, you need to check your differential. The measurement will probably not be cheap, but if you murdered the differential at your own request, do not spare the money for checking.
  • #4 4172585
    neo_dc
    Level 32  
    If the measurement is to cost half a new differential, is it worth having fun? Check if the cable has burned out somewhere, if not - then replace it, and if you do not feel up to it, ask someone who knows it.
  • #5 4172700
    ZBIGNIEW GOGULSKI
    Level 21  
    Jekaterina wrote:
    The RCD will trip when current flows between N and PE. Shorting L and N does not switch off the differential, but only damages it. Checking the differential consists in shorting the wires: N and iPE (at home, of course). There are meters to check RCDs, and if the test doesn't work for you, you need to check your differential. The measurement will probably not be cheap, but if you murdered the differential at your own request, do not spare the money for checking.
    Shorting the N-PE conductors without any load connected does not cause the residual current device to trip (tested in various installations, even in rooms in the power plant, I have recently checked this topic myself in practice) only when any load is turned on, then the N-PE conductor is short-circuited. will turn off.

    Added after 7 [minutes]:

    if after shorting the phase with the protective pin, it does not break the differential and pressing the test button does not do it either, it is definitely a damaged differential and should be replaced, but there are devices that are used to check differentials, among other things, the response time is measured, the current at which it breaks out, but if so, it behaves as you write it does not make sense to measure it, just replace it with a new one
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  • #6 4172759
    Bolo_Yeung
    Level 14  
    First, I will mark: I am not a specialist, all my experience comes from minor repairs - sockets in the walls, etc. - as well as from several health and safety trainings in which I had the opportunity to participate. So I am asking people who do this professionally to correct me if I am wrong.

    I noticed that often, probably for the wrongly understood cable economy, the pin is connected to the neutral conductor - as a friend of the electrician explained to me, the PE and N conductors are abandoned in favor of a common PEN. In such a case, it should not trigger the operation of the differential fuse from what the L wire with the pin should be - both the PEN and L wire currents with the same current value.
    Perhaps this is what the installation in mis_dj's home looks like? .
    Edit: I did some research - it's about the type of TN-C network.

    The fact that in this case the differential fuse is quite an illusory protection - for long-lasting shocks the fibrillation current is lower than the 30 mA, not to mention the self-release current ...


    Finally, I will say one thing - it is not worth saving on security. It is worth spending a few dozen zlotys on a new fuse (this is probably the cost of differential differentials, typical for "home" applications), instead of risking your life for "savings".

    PS. Ekaterina - what in case of L and PE short-circuit? In this case, the differential fuse should trip ...
  • #7 4172854
    neo_dc
    Level 32  
    Bolo_Yeung wrote:
    as a friend of electricians explained to me, we give up PE and N conductors in favor of a common PEN.


    I would have sent him ... for training ;)

    In such an installation as you write, the differential has no right to work. This is called a protective zeroing. Besides, someone has to pick up the installations that your friend puts on ... I'm curious who :D

    The author wrote that the house is new, so the installation is appropriate - L, PE and N.

    By the way - the author connected this heater with the voltage on? Reckless ...
  • #8 4173023
    woogoo111
    Level 14  
    If you shorted L (phase) with PE (pin) and the differential has not blown, and unfortunately you do not write whether the fuse for this L has tripped, You may of course not have a separate fuse, but an appropriate differential. In any case, if you shorted L with PE and there was no sparks, and no additional fuse popped out, then you probably do not have PE connected.
    As for the TEST button itself, in differentials from a well-known manufacturer, after several or several months of operation, the cause of its failure was quite often the failure of the internal resistor in the differential, used to simulate the leakage. This means that the RCD must be replaced anyway.
    And referring to the earlier statements, the pin in the socket, in installations with an RCD switch, cannot be bridged with N. Różnicówka, then it does not work properly.
  • #9 4173298
    Bolo_Yeung
    Level 14  
    neo_dc: It just so happens that the installations in question are not set up by him. Unfortunately, in many cases there are "savings". It is important to complete the work as quickly and as cheaply as possible - that is why such situations occur. And since it's against the norms ... who would care. After all, they don't live there. As long as there is no accident, no problem.

    Oh, in such an installation the differential will work - usually when a current greater than these 30 mA flows through the human body. So how does he really flick us really well.

    PS. I leave it to the unpleasant guess what happens in the TN-C installation when the PEN conductor breaks somewhere further ...

    mis_dj: you wrote that it had blown the fuse before each time the current ran out - so it is possible that your installation is correct (but it's worth checking yourself).

    It is possible, however, that the fuse was good - as you wrote yourself, you felt "gently" after touching the phase wire directly. Most likely no device had a puncture at this point. No current was flowing through the PE conductor and in this situation the only one that leaked was the one going through the body. A typical fuse used in a home installation works most often at 30 milliamperes, and the electric shock cannot be classified as "delicate".

    Although I would not risk - it is better to replace the fuse, especially since there is definitely something wrong with it (problems with the "test :) ...


    Edit: I just found ... I recommend it to all those who think about "saving" on the safety of the electrical installation
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  • #10 4177809
    ZBIGNIEW GOGULSKI
    Level 21  
    Bolo_Yeung wrote:
    neo_dc: It just so happens that the installations in question are not set up by him. Unfortunately, in many cases there are "savings". It is important to complete the work as quickly and as cheaply as possible - that is why such situations occur. And since it's against the norms ... who would care. After all, they don't live there. As long as there is no accident, no problem.

    Oh, in such an installation the differential will work - usually when a current greater than these 30 mA flows through the human body. So how does he really flick us really well.

    PS. I leave it to the unpleasant guess what happens in the TN-C installation when the PEN conductor breaks somewhere further ...

    mis_dj: you wrote that it had blown the fuse before each time the current ran out - so it is possible that your installation is correct (but it's worth checking yourself).

    It is possible, however, that the fuse was good - as you wrote yourself, you felt "gently" after touching the phase wire directly. Most likely no device had a puncture at this point. No current was flowing through the PE conductor, and in this situation, the only one that leaked was the one going through the body. A typical fuse used in a home installation works most often at 30 milliamperes, and the electric shock cannot be classified as "delicate".

    Although I would not risk - it is better to replace the fuse, especially since there is definitely something wrong with it (problems with the "test :) ...


    Edit: I just found ... I recommend it to all those who think about "saving" on the safety of electrical installations

    Buddy Bolo, please do not confuse the concept of a fuse with a residual current device. Regarding the differentials used at home, the most common one is 30 mA, although more sensitive (10 mA) are also used in particularly dangerous rooms where there is increased humidity, e.g. a bathroom. In practice, differentials with a lower leakage current are already knocking out already by 15 mA, they are often knocked out. Regarding the question regarding the connection of the pin with the neutral wire (working zero), if you connect the load to this socket, such as an electric stove or a boiler, which have a connection between the housing and the ground, there will be electricity and the differential will turn off. It could have been somewhere, when you write in some installations, made in such a way that this particular circuit from the savings was not connected by a differential and then it will work but it will not be in accordance with the standards applicable to current installations
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  • #11 4179267
    Bolo_Yeung
    Level 14  
    I have come across the following terms for an RCD: "differential", "RCD", " fuse This is why I wrote about the "fuse". It is obvious that I meant the discussed residual current device all the time.
    Hope this cleared up the misunderstanding.


    If the only leakage current (with the exception of the leakage current, which is negligible in the new house) is the leakage through the human body, then the differential may - with a weaker current flowing through the body - not work, even with the TN-S network. The release current is about 15 mA - a typical house differential works, as you wrote, at 30 mA.
    So, touching the phase conductor and light an electric shock may not have tripped the RCD, even when it was fully functional.

    Quote:
    Regarding the question regarding the connection of the pin with the neutral wire (working zero), if you connect the load to this socket, such as an electric stove or boiler, which have a connection between the housing and the ground, the current leakage will occur and the differential will turn off.


    Assuming, of course, that there is a puncture on the housing ... and yes, in this case the differential will work immediately, giving a signal that something is wrong with the device. Mis_dj wrote one clearly that he touched the phase conductor directly.
  • #12 4179325
    ZBIGNIEW GOGULSKI
    Level 21  
    Hello recently, checking the operation of the differentials in the electrical installation, after checking that they are working properly, my son-in-law expressed a desire to check on himself whether the differential would turn off or not. As he was wearing work boots, he first touched the phase and, to his surprise, he did not feel anything, only after a while we were surprised to find out that he was isolated from the floor with a rubber sole. So he tried again, touching the wall with one hand and with a quick movement of the palm, he touched the phase - he felt a kick at that moment, but the differential did not turn off. I did not agree to the next attempt because I had no intention of resuscitating him. I think that in this situation the current was so small that it did not turn off the differential and the human body felt it. In a situation where a person was more earthed, the differential would certainly work, but the shock effect would also be greater. I note that the differentials were checked earlier that they break out, I do not recommend such checking to anyone, it is stupidity caused by curiosity
  • #13 4179430
    kierbedz4
    Level 36  
    In my case, I check the operation of differential 1 by triggering it with the TEST 2 button, in the second case I check the operation of the differential by connecting a 40w bulb in the socket between the wire in socket L1 and the PE pin, which is a safe non-invasive move for the differential. Checking the differential by shorting the L1 wire with PE will lead to a short circuit and, as a consequence, an electric arc, which may result in welding the contacts in the differential to be replaced. The differential permanently installed in the switchgear should be reset with the test button once a month and once a year subjected to a technical test with a differential tester whether it still meets the technical requirements and to the issuance of a protocol allowing or not allowing the differential to be further exploited.
  • #14 4179461
    Bolo_Yeung
    Level 14  
    ZBIGNIEW GOGULSKI: Well, I think we've already agreed. as for the assessment of the situation described by mis_dj ...
    Either way, the differential to be replaced shouldn't save on security

    And as for the described "testing" accident - even a current close to the self-release current (for alternating 50 Hz, 12-15 mA if I remember) flowing for maybe a second may cause permanent irregularities in the work of the heart's stimulus mechanism. Especially when the current flows from one hand to the other .

    And I know this unfortunately from the autopsy.
  • #15 8621496
    marekcherubin
    Level 12  
    kierbedz4 wrote:
    In my case, I check the operation of differential 1 by triggering it with the TEST 2 button, in the second case I check the operation of the differential by connecting a 40w bulb in the socket between the wire in socket L1 and the PE pin, which is a safe non-invasive move for the differential. Checking the differential by shorting the L1 wire with PE will lead to a short circuit and, as a consequence, an electric arc, which may result in welding the contacts in the differential to be replaced. The differential permanently installed in the switchgear should be reset with the test button once a month and once a year subjected to a technical test with a differential tester whether it still meets the technical requirements and to the issuance of a protocol allowing or not allowing the differential to be further exploited.

    I wonder if this rather primitive but (so far) effective test with a light bulb, and in my particular case, an 8k? resistor between the L1 wire and the PE pin in the socket, could be the cause of the differential difference. After the above-mentioned treatment, the differential worked, but for the last time. Now it is not triggered by the "test" button or the above-mentioned attempt. Differential, and more specifically the 16 / 30mA 1-phase residual current circuit breaker Shracka was 9 years "in service" ... or maybe age is the reason ...
  • #16 8621537
    romoo
    User under supervision  
    Buddy, buy a new differential.

    And since the test destroys the differential, unless the 5 kg strength test with a hammer.
  • #17 8621624
    czesiu
    Level 37  
    The resistor in the RCD has a lower power than the actual power dissipated on it, because it is supposed to work only for a moment.
    Older RCD models did not have an additional contact to disconnect the test circuit and when two conditions occurred simultaneously: the RCD was powered from the even contacts and the user unknowingly pressed the test button for a longer time, this resistor simply burned out.
    Current RCDs have an additional contact that disconnects the circuit from the resistor, which can be seen in their diagrams, then the probability of damaging the resistor is minimal.
  • #18 8621641
    marekcherubin
    Level 12  
    romoo wrote:
    Buddy, buy a new differential.

    of course! I will not avoid it

    romoo wrote:
    And since the test destroys the differential, unless the 5 kg strength test with a hammer.

    hence my question, because I also thought that by letting this 30mA into the ground anyone (including myself) would not hurt.

    Added after 8 [minutes]:

    czesiu wrote:
    The resistor in the RCD has a lower power than the actual power dissipated on it, because it is supposed to work only for a moment.
    Older RCD models did not have an additional contact to disconnect the test circuit and when two conditions occurred simultaneously: the RCD was powered from the even contacts and the user unknowingly pressed the test button for a longer time, this resistor simply burned out.
    Current RCDs have an additional contact that disconnects the circuit from the resistor, which can be seen in their diagrams, then the probability of damaging the resistor is minimal.

    Thank you for valuable information, but let me remind you, I wonder if the reason was the described test with a resistor between L1 and PE in the socket and in it the resistor in the RCD test circuit, it did not take part.
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Topic summary

The discussion revolves around methods to test a Residual Current Device (RCD) following an electrocution incident involving a heater. Users emphasize that if the RCD does not trip during testing, it is likely damaged and should be replaced. Various testing methods are discussed, including shorting the neutral (N) and protective earth (PE) conductors, which should only trip the RCD when a load is connected. Users recommend using a differential tester for accurate assessment, although some suggest simpler methods like connecting a light bulb to check functionality. Concerns are raised about improper installations, particularly regarding the connection of PEN conductors, which can compromise safety. The importance of regular testing and maintenance of RCDs is highlighted, with a consensus that if the device fails to operate correctly, replacement is necessary for safety.
Summary generated by the language model.
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