Need a portable RCBO to trip faster than general

[Energizer]

If you are touching phase and earth together to test this, be aware the current will be in the 100s of amps, not mA

Why 100s? The current is in amps, but RCD trips in 30-40ms and disconnect the circuit. This can happen in real life when you plug in a device with insulation fault, the phase is touching the ground of faulty device

 

[DPG]

Why 100s? The current is in amps, but RCD trips in 30-40ms and disconnect the circuit. This can happen in real life when you plug in a device with insulation fault, the phase is touching the ground of faulty device

Think about the instantaneous current that flows when there is a direct phase to earth short circuit. It may only be for a few mS, but it is a large figure.

 

[Rockingit]

At this point..... "I'm out". The OP is showing a significant lack of knowledge for what they're asking and using a potentially lethal method of testing.

 

[brianmoooore]

If you arrange for the fault current to start at zero and slowly build up, then you will get the discrimination you desire, but this is not what you are doing.
You are applying a fault current of at least many tens of amps which will be reach its peak in a maximum of 5mS, which will trigger both RCDs. That's what they're designed to do and that's what they do.

 

[Energizer]

Think about the instantaneous current that flows when there is a direct phase to earth short circuit. It may only be for a few mS, but it is a large figure.

I wrote before about the important current that flows to the ground for a few ms. And I explained that this is only a test. But this happened in real life before when a user plugged in a faulty device with direct leak to the earth. The users don't think when they plugs in a faulty device. From another point of view, I want to secure the users outlet without modifying the electrical circuit by adding a dedicated RCD in the main distribution board. Well, we will see what we can do...

 

[Energizer]

If you arrange for the fault current to start at zero and slowly build up, then you will get the discrimination you desire, but this is not what you are doing....

And not that the users are doing when they just plug in a faulty device that leaks to ground. I'm simulating this (in the name of the science) and trying to find a solution.
I agree that the both RCD do what they are designed to do.

 

[DPG]

And not that the users are doing when they just plug in a faulty device that leaks to ground. I'm simulating this (in the name of the science) and trying to find a solution.
I agree that the both RCD do what they are designed to do.

I really would stop testing like this if I were you. It is not particularly safe, and will stress the RCDs unnecessarily.

 

[Energizer]

Nobody here mentioned the term of ''selective tripping'', when you have 2 RCD in cascade. In my case, I should replace my general RCD by S type one. The selective residual current protective devices have the identification code S. S=selective. And second RCD should be instantaneous design or short time delayed design, type K

Those who are lacking the knowledge are scratching the head and leaving out

 

[Energizer]

I really would stop testing like this if I were you. It is not particularly safe, and will stress the RCDs unnecessarily.

Don't worry about that

 

[DPG]

Nobody here mentioned the term of ''selective tripping'', when you have 2 RCD in cascade. In my case, I should replace my general RCD by S type one. The selective residual current protective devices have the identification code S. S=selective. And second RCD should be instantaneous design or short time delayed design, type K
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Those who are lacking the knowledge are scratching the head and leaving out

We are well aware of those, but you were specifically asking for quicker RCDs!!

Doh, I'm out.