Residential electrical installations - best practices?

[OneMoreFarang]

I have some background in theory and practice with electrical installations from a long time ago.

I know about wire sizes, MCBs, RCBOs, etc.

 

I do the electrical installation in my new renovated condominium myself. I am pretty sure that I know how to do it technically correct.

 

What I don't know are best practices. I.e. when to use RCBOs instead of RCCBs with MCBs?

If I have a circuit with just one 100W device, should I use a 6A MCB, the smallest available (i.e. from ABB), or is 10A just fine?

My kitchen has a left side and a right side. Does it make sense to have one MCB for each side?

 

I am looking for a website with information like above or a small book. If possible I don't want to read a 1,000 pages book or look up lots of different details in different places. As far as I know there is often no right or wrong. It is a question of what is recommended and sometimes what makes sense compared to how much money spent for each little detail.

 

Until now I have the following situation:

I have empty pipes to each switch, power outlet, etc.

Large wire trays in the ceiling. I have ceiling tiles and can easily open the ceiling anywhere and add new cables or change anything.

I have one large breaker box with some RCBOs i.e. for the water heater, hobs, etc.

Two rows with each a RCCB and many MCBs.

In total I have space for about 40 MCBs (or similar).

 

Can anybody of you recommend some websites, books, etc.?

Thanks

[Crossy]

Have a look at this guide. https://www.tlc-direct.co.uk/Book/1.1.htm

It's aimed at UK regs but the principles are the same.

 

The Aussie regs are closer to Thai installations, but I don't have a simple guide. 00. AS_3000_2018.pdf

 

 

[sometimewoodworker]

4 hours ago, OneMoreFarang said:

What I don't know are best practices. I.e. when to use RCBOs instead of RCCBs with MCBs?

If I have a circuit with just one 100W device, should I use a 6A MCB, the smallest available (i.e. from ABB), or is 10A just fine?

My kitchen has a left side and a right side. Does it make sense to have one MCB for each side?

The general guide is that MCB’s protect the wiring, so you can go lower than the suggested size but there is no particular point to doing that.

RCCB’s while protecting the wiring also protect (in most cases) the people.

multiple RCCB’s can make isolating a fault easier but shared neutrals can make a lecky’s life a nightmare.

Multiple circuits can allow a greater load in a single room and if a fault happens only a single circuit is likely to be effected.
 

I probably have many more circuits in my workshop than is necessary but I have extreme flexibility in citing  tools

 

None of the above addresses the fact that probably most MCB’s in domestic use in Thailand are type C and they should be type B

Edited July 20, 2023 by sometimewoodworker

[OneMoreFarang]

15 minutes ago, sometimewoodworker said:

multiple RCCB’s can make isolating a fault easier but shared neutrals can make a lecky’s life a nightmare.

Thanks for your information.

 

I saw some videos on YouTube about mixed neutrals and the problems with that. It was scary enough to remember it.

It seems two RCBOs are not recommended in some countries to that only "half" of everything is off. I.e. a light in one room is off but in the next room the light is still on.

 

19 minutes ago, sometimewoodworker said:

The general guide is that MCB’s protect the wiring, so you can go lower than the suggested size but there is no particular point to doing that.

I never thought about that but obviously it makes sense. A 6A or 10A MCB won't make a difference to safe a human life. That's the job of the RCCBs.

The smallest cable which I intend to use are 1.5sqmm. 

[sometimewoodworker]

12 hours ago, OneMoreFarang said:

 

I saw some videos on YouTube about mixed neutrals and the problems with that. It was scary enough to remember it.

It is actually shared neutrals, the phrase “mixed neutrals” AFIK  is semantically meaningless, though I can’t think of a situation where it would be scary.

12 hours ago, OneMoreFarang said:

It seems two RCBOs are not recommended in some countries to that only "half" of everything is off. I.e. a light in one room is off but in the next room the light is still on.

The regulations regarding electricity wiring are generally specific to a wiring scheme so grabbing bits hear and there without understanding exactly why they are as they are can be a poor idea.

[bluejets]

On 7/20/2023 at 6:03 PM, OneMoreFarang said:

Can anybody of you recommend some websites, books, etc.?

SAA wiring rules (current version).

Will set you back in excess of $400 AUD.

 

You'll also need some direction from a lecky as it can get rather mind altering just trying to understand.

Sadly, due to the current trend of replacing diagrams with words, it can be open to interpretation in places.

Edited July 21, 2023 by bluejets

[Crossy]

1 hour ago, bluejets said:

You'll also need some direction from a lecky as it can get rather mind altering just trying to understand.

Sadly, due to the current trend of replacing diagrams with words, it can be open to interpretation in places.

 

Does Aus produce anything like the IET On-site Guide https://shop.theiet.org/on-site-guide-bs-7671-2018-a2-2022-8th-edition which contains the essentials without the salad-dressing and is rather cheaper?

 

Or, something like the TLC site I linked to earlier?

 

The Aussie regs are rather closer to the Thai requirements than the IET Regs. but the full book is expensive and mind bending for the average chap.

[carlyai]

This is a bit old, but gave me the idea of how to wire my house and garage.

I downloaded this free of the internet then printed the book.

I drew up the wiring plan using the examples in this book and had the builder(sss) install conduit in the cavity walls up to a raceway ontop of the bondbeam. 

It doesn't specifically go into RCBOs etc. but give a grounding in how installations work.

An electrician did the final installation, but the planning etc gave me the confidence to wire up our 3 room garage and greenhouse.

So if you have a small wiring project, plan it out, work out your loads etc, do the installation, then cross reference Crossy's sites.

 

 

 

[carlyai]

You can order type A RCCB at Sonepar.th.

 

A while back a couple of us were looking for 3 phase RCCBs and the other guy found what we needed.

This is his quote: '

A9Z21425 Acti9 iID 4P 25A 30mA A RCCB

that costs 2660 baht.

We had to pre-order it and most other type A RCD's through Sonepar.th company as they are mostly not available locally.'

So if you want type A RCCBs then maybe Sonepar is the company to see.

[connda]

We rewired the structures on our property a few years back and put all the wiring through PVC wiring conduit. 

[bluejets]

On 7/22/2023 at 8:57 AM, Crossy said:

Does Aus produce anything like the IET On-site Guide

Not as far as I am aware , Crossy.

I did look for any reference on the SAI site however it appears they do a copy as well as sections of the rules normally outside the scope of the standards which SAA do anyhow.  https://infostore.saiglobal.com/en-au/standards/wiring-rules-bundle-2022-1306048_saig_as_as_3181015/

Again at a price, equally as mind bending I'd imagine.

All documentation from SAA is the same complexity.

When doing the hospital refits/extensions we had to have a folder overflowing with standards to cover many extra sections.

Can't imagine any "watered down" AS3000 as any argument or reference one has, has to refer to the AS3000 directly.

Always something new to add as well.......many times received the "latest" with an extra folder full of amendments to glue in to the newly acquired book.

Still, have to keep up as our licence renewal every 5 years is a "zero mistakes" application.....no 75% pass here.

Edited July 23, 2023 by bluejets

[The Theory]

On 7/20/2023 at 3:03 PM, OneMoreFarang said:

My kitchen has a left side and a right side. Does it make sense to have one MCB for each side?

I did my house wiring by myself. The house is small (50sqm), but modern. I used all Schneider products, specially love the breaker box (MCB/RCCB, 14 breakers+lightening protector). The house is small but many different electrical sections than makes it easy for troubleshoot in case of an electrical problem. 

The kitchen has 3 different lines. 1 line with 16A breaker, 2 outlets in 2 opposite walls for 2 refrigerators (RCCB). 2nd line 16A breaker for 2 switched outlets + 1 for kitchen hood (RCCB). 3rd line 10A breaker for kitchen TV and blower above kitchen door (no RCCB).

All 3 lines used 2.5sqmm wires.
 

[KannikaP]

On 7/20/2023 at 4:48 PM, Crossy said:

The Aussie regs are closer to Thai installations, but I don't have a simple guide.

Simple guide....just leave the earth cable off.

[Crossy]

1 minute ago, KannikaP said:

Simple guide....just leave the earth cable off.

 

Even when the appliance states "this appliance must be earthed" in Thai!