RCBO's, Individual Circuit RCBO's, and some questions.

[Crossy]

8 hours ago, Thainesss said:

So a wire bridge would basically be a jumper between the level changes, right? What size wire?

As big as you can bend to fit 10mm² minimum.

 

These slight differences in parts from different manufacturers are a bit of a pain, but not insurmountable ????

 

[Thainesss]

Well I got it all done, and only had a slightly minor snafu and im pretty sure it was down to shared/borrowed neutral (or something). My hot shower was supposed to be on its own dedicated circuit with 3 wires going from the breaker box directly to the hot shower, but when I got everything turned on - 2 RCBOS would trip so somehow the 2 circuits were interconnected and it probably happened during an extention to the house. So after farting around in the attic space with a voltage detector trying to trace wires and trying not to fall through the roof I found that the hot shower wiring was spliced with a section of 1.5mm2 wire and was HOT almost melted. I have a 6000 watt shower on a 32a breaker. 

 

So I ran new 4mm2 wire to the shower and that fixed everything, and maybe avoided a house fire so thats good. 

 

On 1/12/2019 at 8:58 PM, Wirejerker said:

Use the bus and cut it at the change of levels and use wire bridges between the levels. I would leave a gap of one or two poles next to the 32A CBs for future upgrade. You can fill the gap for now with a CB from the old board

 

On 1/13/2019 at 5:41 AM, Crossy said:

As big as you can bend to fit 10mm² minimum.

 

 Got 16mm2 wire up in there pretty easily.

 

 

All done. 

 

 

[Thainesss]

My 2 main takeaways from this little project are this:

 

Im used to working with metal boxes with knockouts that you just tap with side cutters and twist off - done. Clean. 

 

I didn't really think about the fact that I had a plastic box with plastic knock outs until I had the old box removed and was getting ready to install the new plastic one. I tried a couple small taps, nope. Googled it and people said to use the edge of a flat screw driver on the edge of the knockout to pop it out - that cracked the box on the back about a half inch. This box was hard enough to find and I didnt want to damage it experimenting so I used a bare hacksaw blade. 

 

So takeaway 1 - ill never use another plastic box. They crack & flex too easily. Ill use a metal box with actual knockouts. 

 

Takeaway 2 - This box is way too small, all the wires had to be cut to fit, and there isnt any spare wire material in there to change your mind later.

 

If I ever do another project like this ill plan better and order an oversized cabinet type metal box with real knockouts and plenty of space. 

[Thainesss]

Oh and time wise I shut off the power at 07:25 and had the power back on and the air-conditioning running at 11:50 while I cleaned up. Would have been done there had the borrowed neutral thing not happened. Overall I had about 8 hours into it. 

[Crossy]

I always drill plastic boxes with a spade type wood bit.

 

Looks a decent job, and it's a zillion times safer than it was, particularly considering that bit of 1.5mm² on the shower.

[Thainess]

On 1/9/2019 at 12:47 AM, Crossy said:

@Thainess please check my edit in post #5

 

Edit your edit, because that's not me. I'm Thainess and I think you meant to address this to Thainesss.

[Crossy]

1 hour ago, Thainess said:

Edit your edit, because that's not me. I'm Thainess and I think you meant to address this to Thainesss.

Edit edited (added a note), it was a while ago anyway and the thread has moved on.

[Led Lolly Yellow Lolly]

I've not read through this topic but I think it's worth mentioning that I started using a lot of Siemens gear and I'm presently fitting a 3 phase board in our new kitchen. There are some high risk circuits so I'm using single width RCBOs on them and I'm delighted to find the Siemens RCBOs have Functional Earth connections.