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rd400f
14-01-2010, 12:33 PM
Hi
I cant think where ask to post this so here it goes.

Can you guys have a look at the pic and comment on how the RDC is wired up.
Is it correct?...It is mainly the Nuetral wires highlighted by the blue arrows that I want you guys to look at.
1051

Thanks
Richard

Speedy Gonzales
14-01-2010, 12:42 PM
Link doesnt work whatever it is. Just goes to the login screen. And I'm already logged in

rd400f
14-01-2010, 12:49 PM
Link doesnt work whatever it is. Just goes to the login screen. And I'm already logged in

Hi
I have attached a small JPEG of a circut I did in M/S Paint.
I used the paper clip symbol to attach it.Is this wrong?
Richard

Speedy Gonzales
14-01-2010, 12:52 PM
What clip? Click on manage attachments underneath when you reply. Remember it can only be so big.

Sweep
14-01-2010, 12:58 PM
http://pressf1.co.nz/attachment.php?attachmentid=1051&d=1263425517 (http://pressf1.co.nz/attachment.php?attachmentid=1051&d=1263425517)

I got this from the original link if it helps.

rd400f
14-01-2010, 01:01 PM
Hi
I cant think where ask to post this so here it goes.

Can you guys have a look at the pic and comment on how the RDC is wired up.
Is it correct?...It is mainly the Nuetral wires highlighted by the blue arrows that I want you guys to look at.



http://i1022.photobucket.com/albums/af346/gsx750esd/Summer%20Nats%202010/RCDWIRING.jpg

Richard

zqwerty
14-01-2010, 03:31 PM
The idea of an R.C.D. is to check that all the current running through the Phase wire returns via the Neutral wire, if they are not the same then that means some current is going elsewhere ie through you to ground and may kill you. The R.C.D should sense the difference and trip the circuit before you even feel it.

Looking at that diagram I would say you have not achieved the correct configuration.

Speedy Gonzales
14-01-2010, 03:34 PM
This may help (http://en.wikipedia.org/wiki/Residual-current_device)

Terry Porritt
14-01-2010, 05:23 PM
The neutral from the RCD should run to each of the MCB protected circuits, NOT back to the (main) neutral bus, as zqwertys indicates. It is not doing anything as it is supposedly wired.

http://www.stewartsgroup.co.nz/19/news/28.html

http://www.stewartsgroup.co.nz/downloads/RCD%20diagram.jpg

Edit: option 2 in the circuit diagram

rd400f
14-01-2010, 06:22 PM
Hi
I dont quite understand this statment.
"The neutral from the RCD should run to each of the MCB protected circuits"
As all the neutrals from each MCB run to the main Nuetral bar anyway.

But have a look at this pic.
Probably still not right but I'm trying

http://i1022.photobucket.com/albums/af346/gsx750esd/rcdwiringmk2.jpg

Thanks
Richard

Terry Porritt
14-01-2010, 07:09 PM
If you look at the circuit diagram I posted, in option 2 the neutral to each socket or sockets protected by a miniature circuit breaker comes from the RCD neutral bus NOT the main neutral bus which will be used for other supplies such as cooker, air conditioning etc etc.

If the neutrals to these sockets run back to the main neutral bus then the RCD is not in circuit doing anything. They must be connected to the RCD neutral bus.

This work ought be done by a registered electrician, especially if you have to ask :)

Edit: it should also be obvious that in no way should the RCD neutral bus be strapped to earth

decibel
14-01-2010, 09:51 PM
Hi
I dont quite understand this statment.
"The neutral from the RCD should run to each of the MCB protected circuits"
As all the neutrals from each MCB run to the main Nuetral bar anyway.


The Neutral wires returning from the right-side of your picture have to go through the RCD BEFORE going to the Neutral bar.

Under NORMAL working conditions, the amount of current flowing in the phase wire through the RCD must be exactly matched by the amount of current flowing in the neutral wire back through the RCD.

Any slight mismatch will cause the RCD to trip - which is the whole point.

rd400f
15-01-2010, 09:55 AM
The Neutral wires returning from the right-side of your picture have to go through the RCD BEFORE going to the Neutral bar.

Under NORMAL working conditions, the amount of current flowing in the phase wire through the RCD must be exactly matched by the amount of current flowing in the neutral wire back through the RCD.

Any slight mismatch will cause the RCD to trip - which is the whole point.

Hi
Thanks for your reply.
So this should be the correct circut.
http://i1022.photobucket.com/albums/af346/gsx750esd/RCDWIRINGmk3.jpg

With any non RCD circuts having thier neutrals going back to the non RCD neutral bar.
Thanks
Richard

Terry Porritt
15-01-2010, 10:26 AM
Thats right.
What you have labelled the neutral bar is the RCD neutral bus bar.

The incoming neutral wont normally be switched, it's only the phase or live that goes through the main switch, the neutral will run directly to the main neutral bus bar.

This now brings you into line with Option 2 diagram in the link I gave:
http://www.stewartsgroup.co.nz/downloads/RCD%20diagram.jpg

EDIT: I've abstracted the option 2 diagram and uploaded to image F1
http://www.imagef1.net.nz/files/Option_2_-_1_phase_RCCB.jpg

rd400f
15-01-2010, 10:40 AM
Thats right.
What you have labelled the neutral bar is the RCD neutral bus bar.

The incoming neutral wont normally be switched, it's only the phase or live that goes through the main switch, the neutral will run directly to the main neutral bus bar.

This now brings you into line with Option 2 diagram in the link I gave:
http://www.stewartsgroup.co.nz/downloads/RCD%20diagram.jpg

EDIT: I've abstracted the option 2 diagram and uploaded to image F1
http://www.imagef1.net.nz/files/Option_2_-_1_phase_RCCB.jpg


Hi
So this is the final correct circut.
http://i1022.photobucket.com/albums/af346/gsx750esd/RCDWIRINGmk4.jpg
Can I ask why the reg say that you dont have to RCD protect a Permantly Wired product like a stove.
A stove could still have a fault that the RCD would save you from...true?
Thanks
Richard

Terry Porritt
15-01-2010, 12:58 PM
Hi
So this is the final correct circut.
http://i1022.photobucket.com/albums/af346/gsx750esd/RCDWIRINGmk4.jpg
Can I ask why the reg say that you dont have to RCD protect a Permantly Wired product like a stove.
A stove could still have a fault that the RCD would save you from...true?
Thanks
Richard

Presumably it is considered adequate safety is provided for an earthed stove with a fuse or circuit breaker, whereas sockets can have portable appliances/tools plugged in with more potential faults, or even an extension lead with radiant heater balanced on the edge of the bath.................................:clap

I'm not sure why lighting circuits are thought necessary to be protected with RCDs rather than just a mcb, but the use of RCDs does improve safety. in the event of faults.

I did have a colleague in the shop where I worked part time, whose finger skin was so thick he could check for the live wire with his finger...not normally recommended practice.

Since retiring I dont have access as I once did to AS/NZ standards, only what is available via internet, and standards organisations charge an arm and a leg for standards.

I found this Power Point presentation that is relevant:
http://www.deir.qld.gov.au/pdf/eso/wiring-rules-seminar-notes.ppt

rd400f
15-01-2010, 04:41 PM
Hi
Thanks for all your help so far. Can you have a look at these two pics of my dist' board as it stands right now.
http://i1022.photobucket.com/albums/af346/gsx750esd/originalboard1.jpg

http://i1022.photobucket.com/albums/af346/gsx750esd/originalboard2.jpg

Look on the second pic and you can see that it appears that the earth and neutral bus bars are connected by a copper strap.
This is as it was done by a registered sparky not me.
So is it correct ?
So if it is then when the RCD's are fitted the bus bars must be isolated from each other true.
Thanks
Richard

Terry Porritt
15-01-2010, 05:11 PM
If there are no RCDs presently fitted, then the bus bar wiring looks correct, ie the earth bus bar is strapped to the main neutral bus bar as is required for MEN, Multiple Earthed Neutral system

If RCDs (plural, note) are to be fitted then a separate RCD neutral bus bar will be installed, and this bar as already said must not be strapped to earth, as that would negate operation of the RCDs. The neutrals going to the protected circuits will then have to be disconnected from the main neutral bus bar, and connected instead to the RCD neutral bar.

With due respect, you look as though you will be getting out of your depth if you are thinking of installing RCDs yourself, that is a sparkies job by law, it is not covered by current regs/law as a job a home handyman is allowed to do.

I said plural RCDs because there are regs about the number of circuits per RCD.
I also read that if there is no room on the existing power board, then a separate subsidiary RCD power board can be installed.

What I say is not authoratative....I am not a registered electrician, though in a past life I used to design, build, sell, factory install 3 phase machine tool equipment like hydraulic supply units and motorised grinding machine wheelheads and workheads, and heaps of other stuff.

Didn't need a 'ticket' in the UK to do that then :clap

I suggest if you intend going further, then get hold of a good sparky.


Edit: It is just possible that existing bus bars can be re-wired to provide an earthed main neutral bar and an unearthed RCD neutral bar, there appears to be an unused bar at the extreme right in the first picture, or the short bar next to the earth bar appears to be just a connector to the main neutral bar.
This could possibly be used as the new main neutral if only 2 or 3 unprotected circuit neutrals come off it.

rd400f
15-01-2010, 05:45 PM
Hi
Thanks for confirming what I thought.
I will not be doing the final RCD install myself just getting all my ducks in line before getting my pet sparky to knockem all down.
Thanks
Richard

decibel
15-01-2010, 06:28 PM
Also note that if you have more than one RCD, you need a separate RCD neutral bar for each.

Terry Porritt
15-01-2010, 07:27 PM
Also note that if you have more than one RCD, you need a separate RCD neutral bar for each.

A very important point I overlooked, thanks.