rcds rcbos in 3 phase boards

[chris-]

i have been asked to fit three phase board in a block of flats and the drawings state they want mcbs but i will have to rcd protect the circuits. is it just a case of using rcbos throughout cos this will be very costly and also i would want three circuits to trip together but i cant find three phases rcbos only singles. Please help.:banghead:

 

[plugsandsparks]

Schneider do them, look at their Merlin Gerin range

 

[Darkwood]

Yes Sneider do them as mentioned but its not cost effective for multiple circuits as if i recall the rcd unit attaches at the side of the 3ph mcb as a 3 module unit effectively using up 6ways so account for this, ive not used other brands so cant comment, why do you want 3 circuits to trip, im not fully understanding your senerio here. Circuit info from main board to flats consumer unit please

 

[chris-]

isnt it preferred to trip all three phases that is why you get 3 phase breakers so to keep the load evenly spread? can you clarify if this is not the case, cheers

 

[chris-]

so sneider do an rcd which takes up three single spaces so i would need one for each side? i think this is possible.

 

[Darkwood]

isnt it preferred to trip all three phases that is why you get 3 phase breakers so to keep the load evenly spread? can you clarify if this is not the case, cheers

Is this your first time doing 3phase ... you only need to trip all 3phases if you are connected to a 3phase load, im not sure on your circuit design but i assume you are taking a ph1 to flat 1 - ph2 to flat 2 and so on, you dont want a fault in flat 1 tripping power to other flats.... as i said you need to supply circuit design info as i re-iterate im struggling to understand why you require 3ph rcds

Re' to 3ph rcd (schneider) it is 3 module and clips to side of 3ph mcb so a total of 6modules is needed, but these board are one of the most expensive out there mind.

 

[chris-]

the design has each flat has its own 3phase board with 6 showers i think this is why they did this. i wanted 3ph rcds as fitting the entire board with rcbos is costly. i can not get the design tonight as its on the server at work but will have a go at posting it tomorrow. cheers

 

[ipf]

Am I reading correctly '3ph board and 6 showers in each flat' ???

 

[Darkwood]

3phase board at origin of supply, 4core cable feeding a horizontal style 3phase board with 3ph main switch and rcbos covering each circuit, the other methods aint gonna see much cost difference and this way a fault is going to lose all power as area's of the regs do cover this. The cost is what it is, the design team must be aware of the cost implimentations when designing it.

 

[Darkwood]

I await you wiring drafts chris, this don't make much sense and think you may be a bit panicky about venturing into 3ph....and getting muddled, a normal set up would be a 3ph board at origin, a 3core swa 1ph supply to each flat with 17th edition board fitted within the flat and balance the phases over the different flats so as mentioned before ph1 to flat 1, ph2 to flat 2 etc etc

 

[Engineer54]

As darkwood Say's, best to wait for Chris to post his drawing up, as 6 showers per apartment sounds overly excessive to me...lol!!

Then again, these could well be very up-market apartments, built and priced for those that have more money than sense!! lol!!

 

[Darkwood]

think he meant 6showers in total 1 per appartment but nothing would supprise nowadays could be a swingers complex

 

[Knobhead]

How did wiring my flat get on to here? After a typical night we need all six showers, even then it’s a squeeze!

 

[ipf]

I knew there was a simple explanation.lol!