Rcbo???

[Des 56]

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[Kev2632]

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Correct as before they hit the load side where its balanced it goes through the electronics ,its like a wall between the supply neutral and the load neutral if you connect 2 load neutrals together it will trip just like in dual RCD boards when you have a shared neutral

When you say connect 2 load neutrals together are you meaning two different final neutrals from different circuits it will trip the RCBO's yea?

 

[Engineer54]

No... lol!! On a split board you are creating 2 separate RCD zones. The RCD's are also DP So separate line and neutrals to the 2 zones.... mix them and at lest one RCD will trip.


You can connect several RCBO's to the same neutral, be the lines from the same phase or all the phases... There is no imbalance seen because the neutrals are all the same, If you create a split system in the 3 phase DB and split the neutrals bars to suit, then you will have the same tripping problems as a split CU...


Not sure i explained that too well ....i know what i mean anyway...lol!!!

 

[spark 68]

It looks to me that the Neutral is connected from the coil of the contactor and the Neutral bar of the DB.

All the Neutral bars throughout the installation are likely to be connected together (via the various submains/distribution cables, as this is before any of the RCBO's, this will have no effect, the contactor looks to be only switching the Line conductors and not through any RCBO's, the coils will be commoned in parallel to be controlled together.

 

[Kev2632]

No... lol!! On a split board you are creating 2 separate RCD zones. The RCD's are also DP So separate line and neutrals to the 2 zones.... mix them and at lest one RCD will trip.


You can connect several RCBO's to the same neutral, be the lines from the same phase or all the phases... There is no imbalance seen because the neutrals are all the same, If you create a split system in the 3 phase DB and split the neutrals bars to suit, then you will have the same tripping problems as a split CU...


Not sure i explained that too well ....i know what i mean anyway...lol!!!

AHHH yussss i hink ive got ya,Sorrrry blonde moment tonight folks , so does the phases have t be the same then or not can they be off different phases yea?

 

[nickblake]

Ill never make a teacher just cant explain very well lol

 

[Kev2632]

you do dont worry i just need to know about this bit "so does the phases have t be the same then or not can they be off different phases yea?"

 

[spark 68]

I don't see why you cannot switch different phases for each contactor for it's own local circuit, or Item of equipment, or even all three phases for that matter if required.

The coil (control circuit) will have to be on the same phase if they are connected together (commoned)

 

[Engineer54]

AHHH yussss i hink ive got ya,Sorrrry blonde moment tonight folks , so does the phases have t be the same then or not can they be off different phases yea?

You can use any or all the phases, the neutral is the same neutral at the DB's It's only when you create a split zone as in the 17th split CU's with split neutral bars, you get the tripping problem....

 

[Kev2632]

You can use any or all the phases, the neutral is the same neutral at the DB's It's only when you create a split zone as in the 17th split CU's with split neutral bars, you get the tripping problem....

SO would all these RCBO's still be able to detect a borrowed neutral from another circuit, or will it not as the neutrals are all common to each other in this setup???

 

[Engineer54]

SO would all these RCBO's still be able to detect a borrowed neutral from another circuit, or will it not as the neutrals are all common to each other in this setup???

The neutrals are all common, there are no split DP zones on the system...

 

[Kev2632]

The neutrals are all common, there are no split DP zones on the system...

So then the RCBO's won't trip then borrowing neutrals from other circuits will it????
Thanks

 

[Engineer54]

Think about it, ....the neutral is common to all 3 phases, so the sensing circuit won't see any imbalance. You can have a whole 36 pole 3 phase board with all single or multi phase RCBO's protecting every circuit, ....no tripping!!!

 

[SimpleSimon]

No, but they're not borrowing neutrals. Just imagine in your head that all neutrals in that building are connected to one HUGE neutral bar. (even though you view it as different neutral bars in the building.) so each RCBO neutral fly lead after going through the electronics is connected to the same neutral zone regardless of different boards hence no inbalance no tripping

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