4D5A
Has it changed?I've only got my old yellow one beside me and it's 4D2A in there!
10mm Cable Capacity.
- Thread starter Biffco
- Start date
Has it changed?I've only got my old yellow one beside me and it's 4D2A in there!
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4D5A
Has it changed?I've only got my old yellow one beside me and it's 4D2A in there!
Yes, ammendment a few years back, as 4D2A related to test data from round cables, 4D5A was added after tests had been carried out on flat PVC cable, nothing wrong with using 4D2A as the figures are lower than what it was found that flat PVC twin would take, and indeed you have to at times, because 4D5A is rather brief!
Me up to date one is at work - better chuck the yellow one out...
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I've got to hand it to you Softy Boy ... You're damn good entertainment value.
I'm not entirely sure if we're disagreeing on a misunderstanding so I'll make one last attempt to put my point across.
I was simply making the point that when I work out what cable size to install I do current calcs at 230V rather than 240V to ensure I get the highest possible current for any given rated KW.
This in turn means that I will always specify a cable which will meet the load under any circumstances albeit at the overhead of cost i.e. I could end up fitting 10mm2 when 6mm2 would have sufficed etc.
I am not saying that I would rate the circuit MCB based on this however, which, looking back at the previous posts you may have assumed that I meant.
The "stick to plumbing" was meant as a joke for what it's worth
MW
I agree. I've been thinking about charging a fee.megawatt said:You're damn good entertainment value.
I know. But the figure you've selected is arbitrary, and doesn't correspond to the manufacturer's rated load. This means that it's inaccurate.
Yes I quite understood that point.
My only assumption was that your post was superfluous and erroneous.
Since my post was directly in response to Steve's point about a 50A MCB, and your first post on the topic was in direct response to that post of mine, if you weren't talking about MCBs then your point must have been superfluous and erroneous. This means that my assumption was correct.
It was a cracker. It must be the way you tell 'em. Don't give up the day job though.The "stick to plumbing" was meant as a joke for what it's worth
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In that case, let's err on the side of caution & design with 230V in mind, then the higher figure is always allowed for. If in reality it's 240V, then we're safe aren't we?
EDIT: I posted this without reading the whole thread, obviously...
To the OP:
Don't forget to make sure your isolation switch is 50A, too.
Not IMHO - inaccurate doesn't equate to safe.securespark said:In that case, let's err on the side of caution & design with 230V in mind, then the higher figure is always allowed for. If in reality it's 240V, then we're safe aren't we?
But if that's your view, then why not design with an even lower figure?
I mean, if you're going to ignore the manufacturer's stated rating, then you might as well go all the way and use 230V - 6%.
Good morning all, just had a look at table 4D5A and looks like i'll only get 44-47 amps out of a 10 mm cable. Looks like i'll have to settle for a 40 amp MCB. I'm assuming a tybe B MCB is the correct choice for this application?
This days the required calculations of the load in Amps has to be done using 230V.
The MCB is selected after the cable capacity is verified and found adequate for the load.
What you are protecting with the MCB is the cable not the shower.
Being honest if the choice is between nuisance tripping or a damaged cable I will choose nuisance tripping.
The calculated load (no diversity in this case), is about 47A, I think that after taking in consideration all the de-rating factor as the cable run method is not known, you have to stick to the worse scenario. Therefore I suggested a higher capacity cable (type or size) or lower capacity shower. Otherwise I would stick to the 40A MCB.
Last thing, is the main fuse ok for this extra load? If the whole place is protected by 60A fuse and you are adding at least 40A, you might have 'fun' with loosing your main fuse.
The MCB is selected after the cable capacity is verified and found adequate for the load.
What you are protecting with the MCB is the cable not the shower.
Being honest if the choice is between nuisance tripping or a damaged cable I will choose nuisance tripping.
The calculated load (no diversity in this case), is about 47A, I think that after taking in consideration all the de-rating factor as the cable run method is not known, you have to stick to the worse scenario. Therefore I suggested a higher capacity cable (type or size) or lower capacity shower. Otherwise I would stick to the 40A MCB.
Last thing, is the main fuse ok for this extra load? If the whole place is protected by 60A fuse and you are adding at least 40A, you might have 'fun' with loosing your main fuse.
As all the standards of electrics going towards the EU regs. As the wires colour changed, this was expected as well. I do not remember where it is written but I am sure that while doing my 2360 and my 2391 this was mentioned.
In any case I think that it is better to be on the safe side, if you are not sure AND all the difference between using 240V and 230V (in this case) is bout 2A, would this 2A save your day? probably not but a safer approach might save some ones life. Do not forget that we do not have details concerning the method, and what influences are to be considered.
In any case I think that it is better to be on the safe side, if you are not sure AND all the difference between using 240V and 230V (in this case) is bout 2A, would this 2A save your day? probably not but a safer approach might save some ones life. Do not forget that we do not have details concerning the method, and what influences are to be considered.
For a resistive load if the voltage is higher then the current is higher and the wattage disapated at the element is higher.
If you have a rated wattage at 230 volts that means you can calculate the current at 230 volts.
If the actual voltage is 240 then the current will then be higher
I(240) = I(230) times 1.045
Not much higher ( 4.5% ) but enough for a pedantic inspector to reject the calculations as in-accurate.
And if the voltage is higher than 240 volts ( as in close to the substation ) then the current will be higher
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