Circuit design

[mightyworthit]

When designing a circuit is their any advantage or disadvantage in creating more mains ring circuits than necessay. For example, putting the kitchen on seperate circuit, living room on seperate circuit and bedrooms on seperate circuit. Would it be wise to putpumps and heating controls on seperate circuit.

I underatand that the cost of installtion is more, but is there a real advantage or disadvantage other than this?

 

[oharaf]

The greater the number of circuits you have the greater flexibilty for isolation you have. Kitchen are now installed on their own circuit.

As for a shower pump a spur from a ring or radial should generally suffice.

I have installed 5 ring finals in our house, 1 is the kitchen, another is the office the rest was to keep the wife happy when she got home at night so she could watch Corrie whilst I kept working

As for extra cost TBH there isn't that much difference

 

[mightyworthit]

Wow thanks for quick reply!
Do you think it wold be wise if some of the mains ring circuits had small enough load I could use 20a rated device i.e. upstairs bedroom ring ( 2 beds) and CH pump and heating control ring? That is with max power ratings taken into consideration.

 

[oharaf]

As far as I am aware ring finals should be 30/32A, the idea being that 15/16A goes through each leg of the ring.

if you were to use a 20A then only 10A would pass up each leg, that is fine for you BUT what if you sell the house

Remember ALOT of plug in devices are rated to 13A

So my advice is, if you're going to ring it don't wing it!!! 30/32A MCB

 

[sm1thson]

Do you think it wold be wise if some of the mains ring circuits had small enough load I could use 20a rated device i.e. upstairs bedroom ring ( 2 beds) and CH pump and heating control ring? That is with max power ratings taken into consideration.

use rings where may you need the load (eg socket circuits) on things like heater controls you can use a lower rated radial with an appropriately rated MCB.

so basically look at the anticipated max load, pick a higher rated cable (including installation methods etc), pick a higher rated MCB. (and there are other things to consider like voltage drop EFLI etc)

 

[FingRinal]

When designing a circuit is their any advantage or disadvantage in creating more mains ring circuits than necessay. For example, putting the kitchen on seperate circuit, living room on seperate circuit and bedrooms on seperate circuit. Would it be wise to putpumps and heating controls on seperate circuit.

I underatand that the cost of installtion is more, but is there a real advantage or disadvantage other than this?

One of the problems you might face is should...how shall we say it... a less learned person take a look at the installation for whatever reason, he or she might decide that the Maximum Demand is off the scale - due to overly slavish adherence to the OSG.

 

[ban-all-sheds]

Would it be wise to putpumps and heating controls on seperate circuit.

It could be.

As well as the other aspects mentioned above, if you live in an area with a dodgy supply, or if you fear that supplies might become more dodgy in the future, separate circuits like that are more easily powered by a standby generator.

 

[JohnD]

when you instal your RCBOs, you have an extra advantage in having the heating, freezer and alarms on their own circuit - they will not trip at the same time as other circuits, when an earth leak occurs.