B
Blueflash
one would not.
Dave
Dave
Size of Consumer Unit - too many circuits? Potential to reduce quantity?
- Thread starter Bucks_Refurb
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When splitting socket circuits what you want is.
1) Lower loop impedance.
2) Reduced load on each circuit.
3) Ability under fault conditions to swap essential supply sockets.
So it would make sense to supply sockets from RCBO's as then any faulty item will not affect lights or any other circuits, and to split house side to side rather than up and down so in an emergency any extension lead is not going up or down stairs, and the loop impedance is lower as typically side to side needs less cable. It also means during both day and night loads are shared better.
Heating elements using mineral insulated elements like immersion heater and oven may suffer from earth leakage, but alarm panels etc are very unlikely to cause any RCD be it stand alone or combined as a RCBO to trip, so at first glance can all go on one RCD. However alarm panels, chair lifts, cordless phones and the like with rechargeable batteries tend to bleep with a power cut, so arranging for these to share circuits with fridge or freezer can serve as a warning when essential circuits have tripped.
It is rare for MCB's to trip, you are more worried about RCD's tripping, as stand alone best option is two RCD's for the whole house, only by using RCBO's can you increase the number, however a RCBO is expensive specially if looking at 14 of them. Some boards will take single unit width RCBO's with double pole switching, essential with TT supply, but still a better option with a TN supply.
So we split into circuits to reduce load and to reduce what is lost if a circuit trips, and to allow cable which is no oversize to be used. So you want.
1) Immersion heater if fitted.
2) Oven
3) Hob
4) Shower
5) Laundry room (This may be kitchen, but it's washing machine and tumble drier which is heavy load)
6) Lights
7) Sockets
The last two can be further split if you want side to side, but if RCBO used for lights (so unlikely to trip with rest of house) and sockets (so unlikely to trip rest of house) then rest could be supplied from standard twin RCD's, OK in your case you also want office from its own RCBO, but even splitting lights and non laundry room sockets into two circuits that's only 10 circuits.
Since with lights a general power cut will cause failure what ever you do, emergency lighting is better than splitting into two circuits, in my house top of stairs and garage, latter to see consumer unit, in mothers a socket above under stairs cupboard with a Lidi standby touch plugged in, it auto switches on as we open front door showing light switches, it auto switches on with power failure, and I can pick it up to inspect breakers etc when anything trips.
Clearly this all changes house to house, but should give you food for thought.
1) Lower loop impedance.
2) Reduced load on each circuit.
3) Ability under fault conditions to swap essential supply sockets.
So it would make sense to supply sockets from RCBO's as then any faulty item will not affect lights or any other circuits, and to split house side to side rather than up and down so in an emergency any extension lead is not going up or down stairs, and the loop impedance is lower as typically side to side needs less cable. It also means during both day and night loads are shared better.
Heating elements using mineral insulated elements like immersion heater and oven may suffer from earth leakage, but alarm panels etc are very unlikely to cause any RCD be it stand alone or combined as a RCBO to trip, so at first glance can all go on one RCD. However alarm panels, chair lifts, cordless phones and the like with rechargeable batteries tend to bleep with a power cut, so arranging for these to share circuits with fridge or freezer can serve as a warning when essential circuits have tripped.
It is rare for MCB's to trip, you are more worried about RCD's tripping, as stand alone best option is two RCD's for the whole house, only by using RCBO's can you increase the number, however a RCBO is expensive specially if looking at 14 of them. Some boards will take single unit width RCBO's with double pole switching, essential with TT supply, but still a better option with a TN supply.
So we split into circuits to reduce load and to reduce what is lost if a circuit trips, and to allow cable which is no oversize to be used. So you want.
1) Immersion heater if fitted.
2) Oven
3) Hob
4) Shower
5) Laundry room (This may be kitchen, but it's washing machine and tumble drier which is heavy load)
6) Lights
7) Sockets
The last two can be further split if you want side to side, but if RCBO used for lights (so unlikely to trip with rest of house) and sockets (so unlikely to trip rest of house) then rest could be supplied from standard twin RCD's, OK in your case you also want office from its own RCBO, but even splitting lights and non laundry room sockets into two circuits that's only 10 circuits.
Since with lights a general power cut will cause failure what ever you do, emergency lighting is better than splitting into two circuits, in my house top of stairs and garage, latter to see consumer unit, in mothers a socket above under stairs cupboard with a Lidi standby touch plugged in, it auto switches on as we open front door showing light switches, it auto switches on with power failure, and I can pick it up to inspect breakers etc when anything trips.
Clearly this all changes house to house, but should give you food for thought.
A separate circuit for 8 can be useful if provision is made to supply it with locally generated power.
Running a boiler etc. from a circuit that can be easily switched to a local geneartor supply is (if one has a genny!) indeed useful, but it does not necessarily have to be a circuit dedicated only to the boiler. If other things on the circuit would represent too great a load for the genny, they can always be switched off, to allow the boiler etc. to function from the genny.
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New build - a good guess would be whole-house ventilation with heat recovery.
B
Blueflash
Imagine that !
You will be glad of spare ways, you never no what your plans around the corner might be. Better to have spare than not enough.
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