have i got this right

[tom1]

1. cooker circuit.

32 amp mcb, 6mm cable to cooker switch then 6mm to connection plate to feed 45 amp hob. that bits fine, then i took a feed from the connection plate in 2.5mm to feed a 20 amp oven. i think its ok but i could do with a second opinion thanks.

2. 10.6 kw shower put this on a 50amp mcb, a more experianced spark told me to put it on a 40 amp as it would not draw enough power for a 50 amp.

now i need to issue and iec, should i change it back. osg says the mcb can only be higher than the rated current of the appliance never lower.

3. put the imersion on its own 20 amp mcb as it was running off the light circuit 10 amp, also put a towel rad on it. is this a case of a note on the cert under deviations.

thanks for the help

 

[ian932]

Tom is the hob 10.3kw? what is the oven rated at ?

 

[tom1]

hobs 45 amp cooker is 20,

so 10.35 for hob and oven 4.6

 

[Evans Electric]

You can split the cooker circuit for split level stuff but your 2.5 is too small for the breaker, a 4.0 would be the thing to do.

That shower would take more than 40A in theory , so it will be tripping out I presume.

Must be a 2KW Imm.Htr then. I see no problem adding the towel rail to that circuit ,seperate spur ,RCD etc I presume.

 

[Lurch]

What's the run to the hob\oven like? I don;t think I'd put it all on a 32A with 6mm cable. I'd also split the hob and oven to individual circuits, especially with the size of that hob.

 

[Evans Electric]

What sort of hob is that at 45A then ?

 

[tom1]

10 m run

been through the diversity calcs, not too concerned about the mcb or cable size, its just the 2.5 from the hob conection plate, its only 2m of 2.5, and i dont see how its much different than spuring off a ring or at the origen of a ring.

idealy it would be two 6mm from the cooker switch but its just 2 much to terminate so i took it from the hob connection plate in 2.5

 

[tom1]

What sort of hob is that at 45A then ?

not sure yet just been told what was orded

if u do the calc

20 + 40 =65

65 - 10 * 30% + 10 = 26.5 amps

 

[M107]

1) I'd have gone on through with the 6mm.

2) stick with the 50amp so long as cable is rated correctly, but you'd probably find the 40amp would stay in.

3)I always put immersion on it's own circuit.

 

[Andy™]

1. cooker circuit.32 amp mcb, 6mm cable to cooker switch then 6mm to connection plate to feed 45 amp hob. that bits fine, then i took a feed from the connection plate in 2.5mm to feed a 20 amp oven. i think its ok but i could do with a second opinion thanks.

providing the 2.5 can take the fault current to open MCB, and cannot be overloaded (i.e fixed load) then its good. much easier than 6mm where its not needed. other alternative would be 4mm

2. 10.6 kw shower put this on a 50amp mcb, a more experianced spark told me to put it on a 40 amp as it would not draw enough power for a 50 amp.

now i need to issue and iec, should i change it back. osg says the mcb can only be higher than the rated current of the appliance never lower.

showers are usually at rated current at 240v, and lower rating at 230v. 10.6 @ 240 is 44A. you could put it on a 45 or 50A. the 40A will work but may trip, but at this overload, its unlikely to be any time before your finished with the shower

3. put the imersion on its own 20 amp mcb as it was running off the light circuit 10 amp, also put a towel rad on it. is this a case of a note on the cert under deviations.

water heaters over 15L should be on their own circuit. how exactly did it work on a 10A MCB when 3KW is over 13A, plus all other load from lighting?! did it trip often?

thanks for the help

my red

 

[tom1]

dont know how it worked, i found it by accident. may be they had the central heating warming the tank all the time so it was never on for long.

did a zs at the end of the 2.5 got 0.48,

i dont see how it can overload as the oven would not draw over 20 amps,

no fuse though as there would be on a plugged in appliance

 

[ian932]

I get the fact that you are using diversity to work out your MCB size on the cooker circuit but why drop a 32A mcb in when the load could be much higher. I don

 

[tom1]

1) I'd have gone on through with the 6mm.

do u think all this 6mm will terminate

in either three 6mm in 1g 35 mm back box

or two 6mm in 1g 44mm wall mounted this will have to houes the flex for the hob aswell

 

[tom1]

I get the fact that you are using diversity to work out your MCB size on the cooker circuit but why drop a 32A mcb in when the load could be much higher. I don