Eddy Currents

Crosswire · Oct 16, 2013

I vaguely remember an illustration in one of my books showing 3 phases of a supply entering metal trunking seperately, and the words ' THIS ARRANGEMENT IS NOT PERMITTED' emblazoned beneath it.

However I have been going through all my books and cannot find it.....

Anyone know what I'm on about?

Crosswire · Oct 16, 2013

Rockingit said:
Eddy Currents was lead singer in the band Tesla's Coils. They were a bit one hit wonders, with only their single 'Back to EMF' finding its way into the charts. Eventually the band split, and the drummer and bassist went on to form the duo Inductance Moves, which failed to motor as the critics claimed it lacked the necessary spin. Eddy went on to enjoy brief success with his solo album 'Don't stand so close to me (have we met before?)' before retiring to become a plate spinner.

:frown2:......

Only joking 10/10 for effort

snowhead · Oct 16, 2013

Crosswire said:
Sweet. Now if I could find the illustation as well.......

Here's one I did earlier, no alchohol used.

Crosswire · Oct 16, 2013

snowhead said:
Here's one I did earlier, no alchohol used.

View attachment 21021

I'm beginning to think that people are not treating this matter with the solemnity and respect that it deserves....

cossie400 · Oct 16, 2013

Didn't Eddie Currents do "electric avenue"?.........

Crosswire · Oct 16, 2013

Found it!!!!!!

Page 190 of the NICEIC Guide to Inspection, Testing and Certification (5th edition)

I can sleep peacefully now.....

snowhead · Oct 16, 2013

Crosswire said:
I'm beginning to think that people are not treating this matter with the solemnity and respect that it deserves....

:grinningelf::grinningelf::grinningelf::grinningelf::grinningelf::grinningelf::grinningelf::grinningelf::grinningelf:

Knobhead · Oct 16, 2013

The layout I always used for transformes and switch gear when using singles.

E54 would go for a paxoline gland plate, under the regulations (M&Q) I worked to it had to be steel.

Crosswire · Oct 16, 2013

Tony said:
The layout I always used for transformes and switch gear when using singles.

E54 would go for a paxoline gland plate, under the regulations (M&Q) I worked to it had to be steel.

Forgive my ignorance, but why seven holes ( assuming a three phase supply)?

telectrix · Oct 16, 2013

in and out?

Guest111 · Oct 16, 2013

Crosswire said:
Forgive my ignorance, but why seven holes ( assuming a three phase supply)?

3 lives in,3 out and 1 earth?

Knobhead · Oct 16, 2013

Crosswire said:
Forgive my ignorance, but why seven holes ( assuming a three phase supply)?

For hight current it is better to use two smaller conductors per phase (look up skin effect). The neutral normally only needs one conductor.

Modern practice due to harmonics is to use two.

Where high unbalanced harmonic loads are expected. The transformer will be rated type "K" and three neutral conductors provided.

Crosswire · Oct 17, 2013

Tony said:
For hight current it is better to use two smaller conductors per phase (look up skin effect). The neutral normally only needs one conductor.

Modern practice due to harmonics is to use two.

Where high unbalanced harmonic loads are expected. The transformer will be rated type "K" and three neutral conductors provided.

Ah I see.

So where does this leave 521.5.2

" Single-core cables armoured with steel wire or steel tape shall not be used for an a.c. circuit"

Is there something I am not understanding about this Reg? I have a site with massive single core cables all run in swa. Does this Reg not apply to sub mains?

cossie400 · Oct 17, 2013

Crosswire said:
Ah I see.

So where does this leave 521.5.2

" Single-core cables armoured with steel wire or steel tape shall not be used for an a.c. circuit"

Is there something I am not understanding about this Reg? I have a site with massive single core cables all run in swa. Does this Reg not apply to sub mains?

They may well, and most probably will be AWA's. (Aluminium wired Armoured)

Crosswire · Oct 17, 2013

cossie400 said:
They may well, and most probably will be AWA's. (Aluminium wired Armoured)

Ah that makes sense. Good thinking Batman!

Do they then still need to be slotted when terminated onto a metal trunking, as described above?

cossie400 · Oct 17, 2013

Crosswire said:
Ah that makes sense. Good thinking Batman!

Do they then still need to be slotted when terminated onto a metal trunking, as described above?

Hell yeah!!!!

The steel trunking is the issue, as it's ferrous and contains iron, it will have to be slotted.
if the trunking or a gland plate was made from aluminium or brass for example it would not need to be slotted as it is non-ferrous.