4mm radial

[sedgy34]

has anyone spured off a 4mm radial in 2.5mm on 75 mtrs circuit length on 32A mcb

 

[Top Cat]

Your MK link doesnt work TC.
Anyways my 2p is that you'll never get 3 4mm wires in a standard socket terminal anyway.
And most BS double sockets are rated at least 20A.

Hi biff it worked yesterday but not today so i will try it again.

If it does not work go to MK site, wiring devices and downloads.

http://www.mkelectric.com/Documents...pecifications/T02 LOGIC PLUS Tech 355-389.pdf

Read it and weep. Lol

 

[sedgy34]

that's why 4mm is stranded. so you can snip a few off to make them fit. only joking, before i'm crucified)

Tel
are you really joking!

 

[SPARTYKUS]

I've got 3 4mm2 into the back of a socket before, it's a bit like fitting a 16mm2 main earthing conductor into the old Wylex rewirable board earth bar, it doesn't look possible UNLESS you have perfection - if the 16mm2 is perfectly formed cylindrically, it will fit, perfectly. And the same applies with the 4mm2. If they're all un-deformed and go in dead straight it is possible.

However E54 points out it's all a bit tenuous with the screw and number of threads utilised

 

[Geoffsd]

Anyways my 2p is that you'll never get 3 4mm wires in a standard socket terminal anyway.

Of course you can.

How much thicker do you think it is?

 

[SPARTYKUS]

Of course you can.

How much thicker do you think it is?

4mm2 = PI R(squared) = cross sectional area, so looking at it there ain't gonna be much in the radius of one to tuther

 

[Engineer54]

Hi biff it worked yesterday but not today so i will try it again.

If it does not work go to MK site, wiring devices and downloads.

http://www.mkelectric.com/Documents/English/EN%20MK%20Technical%20Specifications/T02%20LOGIC%20PLUS%20Tech%20355-389.pdf

Read it and weep. Lol

Just seen your Link, all i can say is, they are wishful thinking!! The last time i tried 3 X 4mm into the back of an MK logic socket outlet, it was a matter of cropping the cables down. As for getting 2 X 6mm, never been that foolish to even try!! ...lol!!!

 

[CIVILElectrics]

This is allowed page 363 IEE Wiring Regs 17th Edition. Hope this settles it

 

[malcolmsanford]

This is allowed page 363 IEE Wiring Regs 17th Edition. Hope this settles it

Not unless your talking about table 4H2B regarding the volt drop values for multicore 70c thermoplastic insulated and thermoplastic sheathed cable, non armoured (aluminium conductors)....................so not sure where we go with that .........

and it also not page 363 in the Red one either ................are you referring to Appendix 15 ?

 

[Top Cat]

Doesn't really matter as it should be protected by an RCD anyway!

Something i am confused over with Zs is if the circuit is protected by an RCD, as is the case for 90% on a 17th edition board (and the tripping times are within limits) could you put "N/A" in the box for "max measured earth fault loop impedance?

 

[yellowvanman]

Something i am confused over with Zs is if the circuit is protected by an RCD, as is the case for 90% on a 17th edition board (and the tripping times are within limits) could you put "N/A" in the box for "max measured earth fault loop impedance?

You need the still confirm Zs is a reasonable value, based on Zs = Ze + R1 + R2. If using software package to fill in results then to stop the software complaining the measurent is out of spec you should be able to put in max allowed Zs as 1667.

 

[Top Cat]

You need the still confirm Zs is a reasonable value, based on Zs = Ze + R1 + R2. If using software package to fill in results then to stop the software complaining the measurent is out of spec you should be able to put in max allowed Zs as 1667.

Thanks for that, basically what i thought.

Another question:-
I was told off by my NIC inspector for putting down Zs = Ze + R1 + R2 as calculated not measured (i had put down on EIC a note to say that it was a calculation).
He said why do you do it that way? I said because the last inspector told me to!
Well i am telling you to do it by measurement.
I asked is there anything technically wrong in doing it by calculation?
He mumbled no under his breath (as long as you make a note on the EIC) but still wants it done by measurement!
What do most of you do?

 

[yellowvanman]

Nothing wrong with calculation. Also reduces the amount of live testing, because you've done the R1 + R2, you've done the Ze so nothing wrong in adding the two together and putting on the form!

Calculation of R1 + R2 = Zs -Ze is wrong though.

I would always try and do a Zs measurement but sometimes if its difficult to access eg. high level lights use the calculation then.

 

[Geoffsd]

I would say that only the original design (that is working out from the length of the cable) is a calculation.

Although adding together measured Ze and R1+R2, IMO it still counts as a measurement rather than a calculation.

 

[HandySparks]

I was told off by my NIC inspector for putting down Zs = Ze + R1 + R2 as calculated not measured (i had put down on EIC a note to say that it was a calculation).
He said why do you do it that way? I said because the last inspector told me to!
Well i am telling you to do it by measurement.
I asked is there anything technically wrong in doing it by calculation?
He mumbled no under his breath (as long as you make a note on the EIC) but still wants it done by measurement!
What do most of you do?

I queried this at my last ELECSA assessment, particularly regarding the more awkward circuits to test. The assessor said that I should be doing a live Zs test on all circuits. He said that live testing was part of the job and not the same as live working.

I can see his point. It's a good check that no cores have been left disconnected after all other tests. When doing an EICR, on socket circuits I check every outlet. On lighting, I tend to do only one or two which I guess to be furthest from the origin. In fact, when I do a Zs test, I usually do a line impedance test (Z L-N) as well, which is easily done with my Fluke, so I'm checking that the neutral is OK as well as the L & E.

 

[yellowvanman]

I queried this at my last ELECSA assessment, particularly regarding the more awkward circuits to test. The assessor said that I should be doing a live Zs test on all circuits. He said that live testing was part of the job and not the same as live working.

Just goes to show the variability of assessors, I know someone in ECA/Elecsa who continually preaches the Zs = Ze + R1 + R2 calculation and EIC entry