I wonder if the first figure should read 1667 ?, maybe two different operatives ? and one has put the max Zs for the RCD part and the second has put the max Zs for the MCB part ? just a thought.
Okay fair enough, I think we are singing from the same hymn sheet here, when designing a sub-main we go through the assessing compliance bit when we are selecting our cables, and no I wouldn't try to make up the csa as a mix.
I was taught that where PME conditions apply that we allow for the...
They may well be physically connected, but need to be assessed for compliance individually, as in the OPs case in this long thread, the armourings may well comply as a CPC, but not as a MPB, so ideally he would need a 10mm core to fulfil the MPB part, this is what you yourself were putting...
Arghh! we don't, either the core complies, OR the armourings comply for a "straight" CPC, that is what we have been saying, the armourings are earthed for protective reasons where a core is used as the CPC, NOT to make up the csa.
Sometimes we use a core for a bonding conductor, and the...
Oh! god not again, you cannot split the functional requirements of a single protective conductor across different materials.
In this case
Armour complies to equivalent 10mm copper = fine
core complies to 10mm = fine
Neither complies not fine
the other parts of that section
Armour complies as...
well if it was limited to say 3 pitches per cable that would probably not overload, the (16A MCB/RCBO In X 1.45) X 3 off, it could possibly pull approx. 69 to 70 A for about an hour, but the chances of all 3 pitches pulling that amount together for that length of time would be slim I would have...
I suppose it is possible that overload protection has been omitted, and they are only providing fault protection for the 16mm SWA cable buried underground ?
A quick Google it seems they are rated 15kA Ipf, which may be needed depending what the Ipf is at the intake of that board, how long is the run to the RCBOs/caravan pitch ?
This is the argument that is raging lol, the regs say we cannot combine them, different materials ;), GN8 says not, they each have to comply in their own right, ie. 10mm ,or equivalent for the armourings.
This was partly my fault because I originally looked at a dodgy table which was over...
I didn't think Dave was Shouting Charlie, he is making a valid point though, you cannot really make a sweeping statement that the OP is doing it wrong, the manufacturer has told the OP what they want, whilst he does not have to follow their recommendation it may affect any warranty or cause...
Well even in BS7671 there is provision to deviate as long as the same outcome or better is achieved, it tells us this in the good book itself.
Now most sparks (me included) will just follow the book because we are not qualified to know any better, this is no reflection on our ability and...
Seriously ???
If the client is really hearing noises on his Hi-Fi caused by other circuits then I think he has more serious electrical problems to deal with first.
I can see you ending up married to that job lol, "Audio phools" will pay silly money for things like "oxygen free" cable with "enhanced insulation" which they can hear makes a difference to the sound, run forest, run :) lol
That I don't know,
but does the mast have an RA of less than 200 ohms ? ;)
Poor old UK is walking the plank, E54 with the sword behind him, and Tony with the cosh lol :)
H69 strapped to the front as a figure head lol, on the good ship Electrical forum lol :)
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