Rcbo???

[Kev2632]

Im scratching my head here at this, its probably because of the time off night but i cant get my head round this at all, here in the picture is a contactor for the outside lights, now this is one of many contactors throughout the building. there is contactors at each consumer but there is 1 Photocell controlling everything,so all the contactors was linked out to bring them in at the same time. Now every circuit is on its own RCBO, you will notice that they have joined all the neutrals in a connectore block, wouldnt that affect the RCBOS? as they are all coming from different circuits??

 

[Kev2632]

so why can you connect all the neutral leads to just 1 Neutral bar wont the affect the other RCBO's ?

 

[nickblake]

I see that makes sence now ,your flying lead of the neutral is the neutral the circuit neutral is connected to the electronics of the RCBO so balancing out the RCBO exactly as the Live is so realy its live and neutral in through the electronics then out if that make sence

 

[Kev2632]

I see that makes sence now ,your flying lead of the neutral is the neutral the circuit neutral is connected to the electronics of the RCBO so balancing out the RCBO exactly as the Live is so realy its live and neutral in through the electronics then out if that make sence

yea i understand what you mean,so in theory in relation to that photo then, there is no chance of the final circuits (NEUTRALS) being joined together in that connector block then? as there is two different RCBOs supplys there
that would trip it yea?

 

[nickblake]

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

 

[Kev2632]

so basically your saying the Neutral LEAD is the supply neutral to each circuit then yea? it goes out on the live round the circuit and back through the neutral, through the electronics, and up the neutral lead yea? is that right?

 

[Des 56]

.....

 

[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???