New oven and hob wiring

readymix111

Hi all, just wondering what the best practice is for connecting up a 5.7kw hob and 2.3kw oven up to the existing switch backed up by a 32amp breaker

meercat

readymix111 wrote: »

Hi all, just wondering what the best practice is for connecting up a 5.7kw hob and 2.3kw oven up to the existing switch backed up by a 32amp breaker

If you can connect the 2 appliances directly with 6 square back to the cooker switch.

readymix111

Hi meercat, would the 6sq be too much for the 2.3kw oven? Is that how they are normally done? Could 2.5sq be used for the oven and prob 4sq for the hob? Two 6sq cables might be a bit tight for the cooker switch.

mikehammer67

yes it's ok to terminate using smaller cables afaik
as long as they're adequately rated for the connected load

check the manuf. instructions for the oven
it may come fitted with a plug or specify a rating of fuse/protective device
(if you don't you prob void warranty etc.)

readymix111

Cheers Mike, the manuals didnt say too much about the connections, it just had the ratings, no cable came attached either. So just a 3x2.5 heat resistant flex straight to the switch will do yeah? And a 4sq t&e to the hob or should i go for a 6sq to the hob?

mikehammer67

4sq flex for the hob
2.5 for the oven

there's no advantage to using bigger cables to terminate
i'd prob down down to a adaptable box in 6sq from the switch alright-rather than wiring them direct into switch

readymix111

Cheers mike

mikehammer67

yes but as meercat said

i wouldn't actually terminate them into a switch that's sloppy

bucky08

don't see how you can use 2.5mm2 and 4mm2 cable as the breaker that protects your cable is rated at 32 amps at the board so if your down grade cable you must down grade the protective device to 20amps if smallest cable size is 2.5mm2 the protective device is to protect cable not appliance ...

adrian92

Would think 4 sqmm from both appliances back to isolation switch would be best. (possibly ok with 2.5 sqmm on the hob circuit)

mikehammer67

bucky08 wrote: »

don't see how you can use 2.5mm2 and 4mm2 cable as the breaker that protects your cable is rated at 32 amps at the board so if your down grade cable you must down grade the protective device to 20amps if smallest cable size is 2.5mm2 the protective device is to protect cable not appliance ...

i think it's allowed for terminating the cooking apliances
-toasters are wired in 0.75 flex(rating 6A) but fused at 13amp
-pendants 0.75 flex breaker 6-10 amp
-immersion 1.5 flex breaker 16-20 amp


also a similar principal applies afaik for short connections from busbars
the cable may be sized according to protective device downstream if the distance is short

Mr.Fred

adrian92 wrote: »

Would think 4 sqmm from both appliances back to isolation switch would be best. (possibly ok with 2.5 sqmm on the hob circuit)

I assume you mean 2.5 for the oven seeing as how the hob is 24A.

bucky08

so would you use 2.5mm2 cable or have you ever used from cooker switch to hob or oven???

Mr.Fred

bucky08 wrote: »

so would you use 2.5mm2 cable or have you ever used from cooker switch to hob or oven???

Some ovens come with a plug top on them. I'd always use 6sq for the hob if it were electric.

readymix111

The oven and hob didnt come with any cable attached, i might try to wire them both up with 4sq if the terminals allow, if not ill do the oven in 2.5sq and the hob in 4sq. The only 4sq flex i can source is that thick black rubber type, ill go for that due to the heat properties it can take.

adrian92

Mr Fred,

On reflection' I think you are correct - best to use 6 sqmm. Any termination difficulties can be addressed separately.

mikehammer67

i was using the wrong terminology in my posts
i meant the size of the flexible cable not the actual terminations themselves

readymix111

Just a quick update, i decided to run a 4sq heat resistant H07 flex to the hob, for the oven i ran a 4sq flex to a 13amp fused spur and then the 4sq to the oven, thought it would give better protection