Mir hat heute ein Arbeiter die Frage gestellt:
Stell dir vor du hast eine Steckdose mit dazugehörigen Stromkreis. In diesen Stromkreis fällt dauernt der FI und der LS. Was ist passiert?
Kann mir wer weiter helfen? Danke!
(1 votes)
Loading...Hallo Ich habe diesen Kühlschrank in meinem Zimmer. Das Zimmer ist auch gleichzeitig mein Wohnzimmer wo ich Fernsehen schaue und über die Playstation Spiele mit lan Kabel. Immer wenn der Kühlschrank anspringt und dann wieder ausgeht ist es so als würde mein Fernseher dadurch gestört werden und auch das Internet ist dann kurzzeitig weg was…
Vorweg: Es ist mir klar, dass die ehrenamtliche Arbeit keine Jobs gefährden darf. Seit einigen Jahren bin ich einmal im Monat im Repair Café und helfe 3 Stunden lang anderen Menschen, deren Geräte defekt sind. Das geht von der ersten Beurteilung (Schrott oder erhaltenswert) über die Fehlersuche bis hin zur vollständigen Reparatur. Wer will, der…
Wisst ihr lieben wo ich die Lernunterlagen zum Studium für Elektrotechnik herkriege? Habt ihr vielleicht Vitamin B? Oder kennt ihr Leute die solche Unterlagen besitzen? Ist wirklich wichtig danke ihr lieben.
weiß jemand wie dieser stift stecker heißt? das kabel dazu: https://www.robo-ersatzmesser.shop/produkt/kabel-ersatzteil-ladestation-worx-landroid-50035691/ danke
Hey Ihr Lieben, ich habe leider das Problem, dass ein angeschlossene USB A Kabel leider nicht nur Daten wie Mikrofon, Kamera etc überträgt, sondern auch ein Netzwerk. Gibt es da irgendwie eine physische Möglichkeit das zu unterbinden (Kabel ohne Netzübertragung oder nen Adapter) LG Arti
There is a sum current transformer in the FI. In the case of a single-phase alternating voltage, L and N are passed through the sum current transformer. If the sum of backflow and backflow is not equal or deviates too large, the FI triggers.
This deviation thus occurs when the current flowing through L does not flow back over the N in the same amount. This missing quantity is looking for another way, namely via the PE.
The pure FI is therefore a comparator and triggers differential currents.
The LS, on the other hand, is an overcurrent and short-circuit protection device. It triggers when an overcurrent flows too long and thermally triggers the LS or suddenly a very high current flows and electromagnetically triggers.
Let’s assume there’s a full short circuit between L and N. The current may be 3kA arbitrarily. Because the 3kA flows across the L and N alike, the FI does not trigger, but the LS.
Now we assume that there is a body closure between L, the human body and earth. The fault current may be 100 mA. Because the 100 mA flows through L, but no longer back through N, but through PE, the FI triggers, but not the LS, because this current is too low for the latter.
Now we assume that there is a short circuit between L and PE. The current may also be 3kA arbitrarily. These flow via L, but no longer via N, but via PE. The FI triggers, like the LS.
Hm ok I understand, but one thing is unclear to me. When L and Pe touch each other, it would be a short circuit, which makes the Ls lose. Okay, but what’s the difference with a body closure? So why doesn’t the LS trigger a body lock? Why does it trigger in connection between L and Pe, but not in connection between L and zb a housing that is grounded (which would be a body closure or not?) In both cases, a current would flow over the pe. So why is there a short circuit between L and Pe, but between L and a PE-connected housing, no short circuit, but just a body lock? I don’t understand.
When the housing is grounded and the phase L comes into contact with it, this is also a short circuit, one speaks of the so-called perfect body closure. The FI and LS naturally also apply to these errors. Whether the LS comes to triggering depends on whether the FI does not already trigger.
But if the housing is not grounded, the fault trough lacks a path. However, if a connection to the earth is established with this housing, e.g. by your human body, because you now touch the housing, a fault circuit is created. Your body resistance is now decisive for the level of the fault current, which is significantly lower than that of the complete body closure, but is then interrupted by the FI.
I suppose the worker or taskman means a circle where LS and FI are separate, so no combined FI-LS, so you can be sure that both trigger.
Look at the conditions under which these protective devices trigger.
And then look at the mistakes that both trigger simultaneously.
Fi: Body and Earthlock, LS: Overload and short circuit. But I really don’t get on it.
And now find the smallest common denominator. 🙂
When the overload flows towards Earth?
One triggers at too high a current.
The other triggers a fault current.
Naaaaaa?
I really don’t know. I don’t have a solution despite the tips.
This would have to be considered
LS is a protective device for the system.
It’s a circuit breaker.
Technical tricks enabled a small personal protection.
The Fi, professional RCD, is personal protection. He’ll blow what’s coming in, what’s going on.
Differences present RCD switches off.
In the case described, there is probably a connection between L and Pe
But why would the LS trigger an L-PE connection? There is neither an overload nor a short circuit.
Yes. Except you would have nen it-net like me at the time
It’s a rich earth.
for what is predesitinated are devices with heating windings, motors, transformers etc.
here only piece for piece helps to find the error.