You'd maybe better posted that thread in the Non-US subforum.
RCD is not equal to GFCI. A "normal" RCD does not need an normal input voltage voltage to act, it consists of a passive coil adding up the currents going thru. This nowadays works down to 30mA for three phase and 10 mA for one phase systems. The typical cut off time is 10 to 30 ms. In German f.i. they are abbreviated "FI"-switch. A standard GFCI is probably more comparable to a "DI"-switch which is used as additional protection measure but depends on the presence of a reasonable input voltage to run its internal electronics.
In harmonized norms both types are called RCD, but the second type is rare here.
But your point was AFCI. As a matter of fact I've invested the last thirty minutes to understand what that is, still I do not understand how it really works, but I've never heard about that in Western Europe.
May be we have no arcing just shorts?
[This message has been edited by Wolfgang (edited 11-09-2005).]
#58408 - 11/09/0507:43 PMRe: AFCI in other countries??
I spent some time trying to decide if it was better in the General board or non-US board... RCD stands for Residual Current Device. I did't know it was an electro-mechanical device. Here our GFCI's sre controlled by a computer chip and sense the current usinf a biased current transformer torrid which also can tell if the nuteral is connected properly. I understood that RCD's were intended for life safety; is this true? Just that they have a different trip curve? AFCI's work by sensing the shape of the current curve to tell when a sustained arc is taking place. Many AFCI's also have GFCI functions in them as well. We're required to install them in any circuit that serves a lighting or utility outlet in a bedroom in a dwelling. Not any other room, just bedrooms...
#58411 - 11/10/0510:40 AMRe: AFCI in other countries??
Many AFCI's also have GFCI functions in them as well.
They have a GFP function, not a GFCI function. The term GFCI is reserved for life safety with a 4-6 mA trip. The GFP part of the AFCI has a 30-50mA trip. It is my opinion that the GFP part of the AFCI, not the fancy "arc sensing" circuit, does most of the work in the AFCI device. Don
#58412 - 11/10/0503:34 PMRe: AFCI in other countries??
In European power grids passive, electro-mechanical RCDs can do different jobs:
1. in so called "TT-systems" they are mandatory for the whole of the service. In Europe xformers can be pretty far away. TT means that xformer (always star point)ground electrode and your local ground electrode are not bonded. In this case a ground fault will almost never cause an important current to ground able to trip a breaker as the ground resistances will be too high. That's why RCDs are in this case integral part of the system (example: France 2 RCD in series (often 500mA/30mA).
2. Furthermore in any location with an increased danger of fire a 300mA is supposed to prevent fires. Here you have to understand that in Europe there is almost mandatorily an isolated ye/gr ground run alongside every hot wire. In actually Germany we mainly use cables not wires, but that differs. A melting isolation will create a ground contact before external isolation/(plastic!!)conduit is destroyed.
3. For additional protection of persons the same technical principle with a nominal maximum ground fault current of 30mA (Standard)or even 10mA is mandatory for bathrooms, garages , outside in one country, for everything in the next, this depends on local rules and pocos.
With regard to grid forms it is important to understand that the 230 V can either consist of 1 hot and 1 grounded conductor,
or of 1 hot and 1 one conductor only grounded at a xformer a mile away (not accepted as really grounded)
or just 2 hot wires (f.i. Belgium often).
This is why we do not really care about poles , as any of the both "active" conductors in a receptacle can be "not" cold. And therefore a detection of a "bad neutral" is not helpful at all.
#58415 - 11/12/0510:46 AMRe: AFCI in other countries??
30mA trip is generally the most sensitive used in a normal domestic environment here, and is now requried by our code for outside receptacles and for other outlets which are likely to be used to feed appliances used outdoors.
We have no equivalent to the AFCI, and thus far I've not seen even a mention that such things are under consideration here.