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how many MCB´s behind one RCCB? Or use RCBO´s instead?


jim234

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Backhome every 4 MCB´s need to be protected by 1 RCCB. Is that the same practice here in Thailand? 

 

I read that some of you use RCBO´s instead of RCCB´s. In my understanding, a RCBO is a RCCB and MCB combined. Does this mean every circuit has its own RCBO? The obvious advantage of this is that when there is a fault, only 1 circuit will be cut off instead of 4 circuits. Are there any other advantages to justify the price difference between the 2 systems? I will have quite a few circuits.

 

I have another question about the central earth bar box in bathrooms. Backhome we are allowed to connect the central earth bar in each bathroom to the closest conduit instead of running the copper cable all the way to the Main box. Is that allowed here in Thailand as well?

 

TIA

 

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9 minutes ago, jim234 said:

Does this mean every circuit has its own RCBO? The obvious advantage of this is that when there is a fault, only 1 circuit will be cut off instead of 4 circuits

That is what I have in our House, 1 RCBO (Schneider) for every circuit, problem is it is not cheap, but I would rather be without power on one of the circuits then have to go through something like this

 

 

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I saw a couple of videos from a professional UK electrician.

They described it like that: Some time ago (don't ask me how long ago) it was normal to install one RCCB in one breaker box.

And then they "discovered" that in theory that does the job, but if the RCCB is triggered, then all the power is off. That is obviously a problem, maybe with light at night, etc.

And that is why they started the rule that there should be two RCCBs. So if one of them switches the circuits off, then "half the house" still has power.

 

Personally I installed two RCCBs with each somewhere between 5 to 10 MCBs - it's not finished yet.

And then I have a few RCBOs for special circuits, i.e. one for the fridge, so that I can easily switch everything off except the fridge. And one RCPO is for my home automation system to make sure that works independently from all the rest.

I tried to learn more about what is commonly used, and it seems there are no strict rules. Similar like how many MCBs one needs. Some homes have 4, others have 10 or 20. Up to whatever the electrician thinks makes sense. I have lots of MCBs to separate rooms and power and light. Is it necessary? Not really. But MCBs are cheap, so why not.

 

Above is my personal experience, I have some experience with electrical installations but I am not a professional. I am also interested what others say. 

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1 hour ago, jim234 said:

Backhome every 4 MCB´s need to be protected by 1 RCCB. Is that the same practice here in Thailand? 

 

I read that some of you use RCBO´s instead of RCCB´s. In my understanding, a RCBO is a RCCB and MCB combined. Does this mean every circuit has its own RCBO? The obvious advantage of this is that when there is a fault, only 1 circuit will be cut off instead of 4 circuits. Are there any other advantages to justify the price difference between the 2 systems? I will have quite a few circuits.

 

I have another question about the central earth bar box in bathrooms. Backhome we are allowed to connect the central earth bar in each bathroom to the closest conduit instead of running the copper cable all the way to the Main box. Is that allowed here in Thailand as well?

 

TIA

 

DTIA

 

TIA

 

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thx for the replies!

 

My plan was to have 7 RCCB´s with each 4 MCB´s, which will give me 28 circuits. 

 

Using RCBO´s for each individual circuit does add up. I do understand the advantage of only one circuit being cut off instead of 4, but are there more benefits? It doesn´t make the system more safe than what I am propossing, does it?

 

 Using RCBO´s for a few special circuits does sound like a good idea.

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13 minutes ago, jim234 said:

thx for the replies!

 

My plan was to have 7 RCCB´s with each 4 MCB´s, which will give me 28 circuits. 

 

Using RCBO´s for each individual circuit does add up. I do understand the advantage of only one circuit being cut off instead of 4, but are there more benefits? It doesn´t make the system more safe than what I am propossing, does it?

 

 Using RCBO´s for a few special circuits does sound like a good idea.

Also think about the extra wiring within the breaker box.

If you use RCBOs then each of them had two inputs and two outputs.

In "standard installations" you have a neutral bar, and all neutral wires are connected to that bar. With RCBOs they are all separate.

 

This is just a random picture, I didn't find anything better.

Plug-neutral-breaker.jpg

 

 

 

 

 

Edited by OneMoreFarang
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20 hours ago, OneMoreFarang said:

Personally I installed two RCCBs with each somewhere between 5 to 10 MCBs - it's not finished yet.

And then I have a few RCBOs for special circuits, i.e. one for the fridge, so that I can easily switch everything off except the fridge. And one RCPO is for my home automation system to make sure that works independently from all the rest.

Does this mean that you have 3 seperate N bars?

 

One for each RCCB and a third one for your RCBO´s? 

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2 hours ago, jim234 said:

Does this mean that you have 3 seperate N bars?

 

One for each RCCB and a third one for your RCBO´s? 

I have 2 N-bars, separate for each group of MCBs with a RCCB.

And the RCBOs have all separate L and N outputs, no N-Bar. 

And it's important not to mix up the N wires. Because if any of them is not installed correctly then the RCCBs or RCBOs won't work in the way they should work.

 

I use Phoenix terminals - and I am probably the only person in Thailand who uses them. ???? 

https://www.phoenixcontact.com/en-pc/products/terminal-blocks

 

hq720.jpg?sqp=-oaymwEhCK4FEIIDSFryq4qpAx

 

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6 minutes ago, OneMoreFarang said:

I have 2 N-bars, separate for each group of MCBs with a RCCB.

And the RCBOs have all separate L and N outputs, no N-Bar. 

And it's important not to mix up the N wires.

So where do the N tails of your RCBOs go to?

How to make it a close circuit?

Back home we don´t use N bars, so that still confuses me a bit

 

that box looks quite impressive!

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10 minutes ago, jim234 said:

So where do the N tails of your RCBOs go to?

How to make it a close circuit?

Back home we don´t use N bars, so that still confuses me a bit

 

that box looks quite impressive!

My breaker box is still under construction.

Currently I use RCBOs with L and N input and L and N output. I think it's obvious how to wire them.

 

Until now I was not aware of the different types. But it seem important not to use AC type anymore.

So it's time for me to do some shopping...

 

 

 

 

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