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Posted By Topic: Tidy/efficient swb wiring

TimoW
Mar 02 2018 11:02

Hi all,

Just looking for advice or any tips and trick as to how to maintain neat and tidy domestic switchboards. The other day i fitted off a near full 40 way DB. managing the sub circuits is fine but by the time you add in say 3 6.0mm live/neutrals per RCD things start to get a bit full.
Perhaps use a more heavily rated busbar system to feed multiple RCDs??


   

AlecK
Mar 02 2018 12:06

Busbars to feed RCDs are likely to become more common, as new edition of \"3000\" will require that Ns not be simply looped between fittings; the connection has to remain effective continuity even with the RCD (or whatever) removed. Twisting of conductors will not be an acceptable means of ensuring continuity, will need ferrules or similar. Or busbars.
   

mowgli
Mar 02 2018 16:13

AlecK I read something along those lines recently related to ring feeding. Since then and for all looped circuits in the switchboard: I start at the source fitting (e.g. neutral bar) then for each looped fitting I strip some insulation without cutting the conductors, twist it, fold it then secure it in the terminal. After the last looped fitting the wire goes back to the source fitting. Took a few goes to establish the right length of insulation to remove but now it\'s quick and easy.

Do you agree this will satisfy the disconnected continuity requirement?

TimoW I put all those loops in first so they end up behind any subcircuit wiring. I like square corners and cable ties. So everything tends to head out to a side then squarely up. Diagonal wires to me, say I screwed up and cut the cable too short.
   

Satobsat
Mar 02 2018 16:45

I do similar to mowgli except where they come off the neutral bar, in adjacent terminals, I bring them straight down the back of the board behind the rails then out to the sides to loop through the RCDs.
This leaves the sides clear for circuits and above the MCBs and RCDs clear for pigtails.

I also try and avoid square bends and try to have curves instead.

RCCBO din rail is available (active and neutral).

Does anybody think they will switch to RCCBOs in the future anyway eventually i.e. one per circuit?
   

AlecK
Mar 02 2018 17:16

yes, if the conductor isn\'t cut it can\'t become separated when disconnected.

At the smaller scale, eg a control panel with N looped between relays etc, ferrules would be the go - though not strictly a \"switchboard\" so arguably the requirement wouldn\'t apply
   

SparkyJoe
Mar 02 2018 19:52

I really really like the rcbo\'s with the Live and neutral buzz bar however i have no idea how much these are (As im employed at current) but they do a decent job, and you can terminate all the phases first and the neutrals second and it looks sexy as f00k. Id rather put buzbars in from the rccb because its faster and you dont have to fuck on stripping bits of cable.
   

mf51to1
Mar 02 2018 20:14

[quote]TimoW I put all those loops in first so they end up behind any subcircuit wiring. I like square corners and cable ties. So everything tends to head out to a side then squarely up.[/quote]

Yep same here.
I like looming wiring but try to minimise cable ties.
   

Fuel1
Mar 02 2018 20:54

I have used 2 pole comb bus bar to feed the 40/63a rcds and then used 10mm 1c flex to feed both the phase and neutral from the main switch and neutral bar, you can also take feeds off the comb bus bar to feed other mcbs.
   

TimoW
Mar 07 2018 08:52

Have just had a decent search through the NHP website and they have a good busbar system and all the necessary accessories. I get a decent discount on RCBOs and am leaning to just using them instead of RCCBs.
   

mf51to1
Mar 08 2018 22:28

Timo what’s your method of connecting the A from the main switch to the first busbar fed RCBOs? Usually the terminals are quite small to fit a 16mm tail? I’m talking about the single pole RCBO.
   

pluto
Mar 09 2018 09:48

mf51to1 Mar 08 2018 22:28
Your comments
Timo what’s your method of connecting the A from the main switch to the first busbar fed RCBOs? Usually the terminals are quite small to fit a 16mm tail? I’m talking about the single pole RCBO.

My comments
1. All RCD (or RCBO) are required to be double pole in NZ on a single phase supply and be at least Type A (use of type AC RCDs for personal protection purposes is NOT permitted in NZ.)

2. RCBOs to IEC (oe AS/NZS) 61009 (the NZ requuired standard) do have smaller terminals holes than for MCBs. The use of a busbar system for the supply connections is intended by the IEC standard when multiple RCBOs are being used.

For information, as IEC 61009 is not on the EWRB free list, the standard provides for the following terminal sizes;
RCBO Current rating (max) first then - followed by min wire size.
13 A - 2.5 mm2
16 A - 4 mm2
25 A - 6 mm2
32 A - 10 mm2
50 A - 16 mm2
80A - 25 mm2
   

AlecK
Mar 09 2018 10:52

I suspect you meant \"max\" wire size?
   

Sarmajor
Mar 09 2018 12:48

I suspect Pluto is taking single pole to mean single pole switching whereas the previous poster is talking about the RCD’s that only occupy one pole space in the board.
They do have smaller terminals than the RCD’s that take 2 pole spaces.
   

pluto
Mar 09 2018 13:05

Sarmajor Mar 09 2018 12:48
Your comment
I suspect Pluto is taking single pole to mean single pole switching whereas the previous poster is talking about the RCD’s that only occupy one pole space in the board.
They do have smaller terminals than the RCD’s that take 2 pole spaces.

My comment
from IEC 61009, the terminal hole size is NOT dependant on the DIN width (18 mm) of the REBO device.
   

AlecK
Mar 09 2018 13:37

Pluto:
Sarmajor wasn\'t suggesting that the terminal size is dependent on the DIN width;
he was pointing suggesting that mf51to1\'s usae of \"pole\" might mean something different from what you took it to mean.
   

mf51to1
Mar 10 2018 16:14

Sorry for the confusion, yes I was meaning physical size - one pole width RCBO. As sarmajor was saying they have smaller terminals than a two pole width RCD.

   

Tex431
Mar 10 2018 19:55

Any pictures?
   

mowgli
Mar 10 2018 20:13

Mf51to1 the single way, double pole RCBO from NHP easily accommodates a comb busbar and a 6mm wire. So loop in 6mm: main switch to first active in comb, then last active in comb back to main switch.

If the RCBO is the main switch then it is load limiting so just add a 6mm tail to the 16mm. 6mm doubled over in a 16mm straight crimp works well.
   

TimoW
Mar 13 2018 18:26

http://www.nhp.com.au/Media/News/Article/Latest-News/Simplify-installation-with-wiring-solutions-from-NHP

The above link shows how to combine MCBs, RCBOs, and RCCBs tidily.
   

mralarms
Mar 14 2018 02:53

I prefer the Hager double comb as there is no coping out neutral tabs to jump where not required