The UK had it introduced at some stage too, did it end badly there?
Yes.
We've had it for several generations of DIYers and electricians and it is still going wrong all the time.
From your own experience you have electricians there who don't know what a ring final is or that they are now allowed. You tell me what's likely to happen when they are asked to add new outlets to one.
Don't hire cowboys that have no clue and randomly connect things without looking.
Completely wrong.
Sockets A B D & E were the ones originally installed when the circuit was first put in.
In the house in question, there was a "Spine" down the middle of the house from which all the outlets were sourced. Additions had been made to this circuit. That's why I referred to them as "Spurs" off an original circuit.
Because I didn't use the correct terminology for your liking, you now have a stick up your rectum. Solution: Remove stick from rectum.
First, most important, and possibly show stopping question:
With this 2.5mm² cable is In ≤ Iz?
In is 20A, As already stated in the previous two posts I've made.
Iz for my configuration (If I were to be using only ONE 2.5mm² cable) Will be between 20A and 27A, I do not know exactly which figure to apply as there are various environments that the cable will run through (Ceiling with insulation, Conduit in rendered wall etc)
In any case,
In ≤
Iz.
Why do you keep mentioning the lengths?
Lengths of cable under load can have a huge influence on voltage drop, which in turn influences current load in the cable.
I haven't checked VD, but that didn't seem to be your concern, nor have you said what your Ze and maximum EFLI is.
As mentioned in my post, there is no current earth in the existing setup, it is tied directly back onto the Neutral at the outlets, I have no idea what the value of
Ze is as it currently is non existent.
The maximum EFLI I do not know either, I do not know which type of fuses for consumer units are standard here, so I do not have any data sheets in order to calculate maximum EFLI.
Not really, assuming that the installation hadn't been done by an idiot.
Try 3 or 4 idiots over a span of 50 years without any legislation covering it.
OK - I just can't work out why.
Well I don't know, something must be wrong with your head if you do not understand why I would mention that we do not have fuses on plug here like the UK does, after someone mentioned that 32A is permissible for a 2.5mm² ring circuit provided that fuses on plugs are fitted.....
Shouldn't trip - Ib should be ≤ In - you aren't supposed to use an OPD as a load limiting device.
Ib is up to 20A
In is 20A
There for...
Ib ≤
In
How else do you propose to limit the current in a circuit which you do not wish to exceed 20A?
Analyse the wording: OverCurrent Protection Device.
In dum dum speak: "Too Much Current Switchy Offy."
You wish to LIMIT the LOAD on a circuit to 20A.. Makes perfect sense to me, but apparently you have a different take on it, I'd love to hear it.
How will you know what it has where you're installing it?
How will you know that your EFLI is OK for the device?
By using the tables provided in the IEE 16th edition to compute it?
By finding out what type of fuses are standard here, and calculating the required EFLI. Then measuring to see if they are within limits?
You're going to have a 20A ring?
Why?
Is it allowed there?
Yes, for one room.
Because the limiting factor is the 2.5mm2 wiring in ring, and it requires adequate protection. 20A is sufficient for a bedroom. (And it sure as hell beats 63A per phase protection which is currently there.)
Who are you, my father or teacher, your starting to act like I need to satisfy your questions for some obscure reason.
Because it has been discussed with the electrician who will check over the work, commission it and sign it off.
Which is why I asked questions about what and how you knew things.
Would you rather I just made assumptions about what you know and what your background is?
I had a simple question about computing CCC for a ring circuit. Turns out there is no simple answer, there is only the guidance from the BS.
Paul_C said:
That's a simple problem of trying to connect too much load to the circuit though, not one caused specifically by the particular "branching" arrangement depicted.
If the cable ran in a single line as CU - A - B - C- D - E - F, then the leg from CU to A would still be called upon to carry the same amount of current with the loads given in your example.
True,but the difference between radial and ring is the loading via two cables, giving two different paths to reach the same location.
The radial was never designed to have so much added onto it.
Granted, the ring could have the same done to it, but its a lot more logical to me to have zones with rings than having a "loose end" somewhere you can tie into.