Quick question about a cooker switch

Swampy

Hi all,

I'm in the middle of replacing a faulty cooker switch. However the new light on the switch stays on always. I'm sure I duplicated exactly as the wiring before.

the only differences on the back of the switches is the metal bit that the green and yellow wires on to is on the opposite side.

Any ideas? Drawing of the switch attached. The other switch had in and out written besdie the L's and N's. Do these match up with the Load and Feed onthe diagram attached?

Bruthal

You have the supply cable and the cooker cable into the wrong sides. Switch will have supply or feed at one side for L and N, and the other side says load for L an N.

Cooker goes into the Load side.

meercat

spot on robbie

Swampy

so, do I flip them around? as in, the bottom on the top and vice versa.

meercat

Swampy wrote: »

so, do I flip them around? as in, the bottom on the top and vice versa.

yes
as robbie said
swap them around
make sure to turn power off( and tighten screws really tight)

Swampy

Great. Just did it there and its working perfect now.

Thanks for all the help.

creedp

I have a related question but in my case I am replacing the worktop and when disconnecting the hob I noticed that the cable casing just around where it is connected to the hob terminal is slightly melted - just the bit between where the casing terminates and where it is clamped to the hob. It is the heavy duty cable that is used to wire the cooker switch from the fuse box. However, it is wired slightly unusually in that the heavy cable from the switch on the wall terminates at one of those plastic connectors where 2 feeds are then taken - 1 to hob which is the same heavy cable and the 2nd which is the proprietary oven cable which is much lighter and more flexible.

I was wondering why the hob cable had melted where connected to hob but is fine where it is connected to the plastic connector. I was going to replace the plastic connector with one of those heavy duty junction boxes but am concerned to see the casing melting at the actual hob. Any views?

Bruthal

It could be because the cable connections into the hob are not tight enough and the heat from loose connections has overheated the end of the cable.

Any photos?

creedp

Thanks Robbie. Here are some photos of hob connection - sorry about quality, phone camera pretty poor!

Bruthal

Its hard to tell, but it looks ok where it goes into the connectors of the cooker, but damaged where the clamp is. Maybe it was a bit of damaged cable used for the hob. But the best thing would be to have a new piece put in, or cut that bit if its long enough.

The oven flex should not really be directly connected to the cooker switch cable, but maybe through a fused spur connected to the cooker switch. Them ovens are actually designed to be plugged into a 13 amp socket, but a proper cooker joint box and into the hob, and also into a fused spur which then goes to the oven would probably work.

Its electricians work to do a proper job of it anyway.

creedp

robbie7730 wrote: »

Its hard to tell, but it looks ok where it goes into the connectors of the cooker, but damaged where the clamp is. Maybe it was a bit of damaged cable used for the hob. But the best thing would be to have a new piece put in, or cut that bit if its long enough.

The oven flex should not really be directly connected to the cooker switch cable, but maybe through a fused spur connected to the cooker switch. Them ovens are actually designed to be plugged into a 13 amp socket, but a proper cooker joint box and into the hob, and also into a fused spur which then goes to the oven would probably work.

Its electricians work to do a proper job of it anyway.

Unfortunately Robbie it was an electrician who wired it up originally. I was only intending to put it back the same way I found it until I saw the melted casing. Take it form me I am not an aspiring electrician, the most I will take on is replacing a broken plug/socket/light switch. However, I thought reconnecting a cooker hob should be reasonably straighforward ... how wrong one can be:)

Bruthal

They can be awkward enough things to properly connect up even for electricians. In my opinion anyway, cookers and hobs often dont have great terminals in them for connectiong up the proper sized cables.

There is a proper connector box now for cookers that can be got in electrical wholesale shops, which can have the cooker cable from the cooker switch connected into it, and 2 cables out from it, one for hob, one for oven.

But over all, the oven can either have a plug fitted and plug it into a socket connected to the socket circuits, or connected to the second cable from the above junction box, but through a fused spur idealy.

Thats why an electrician is best for it. The way the original one did it is often done, especially years ago. Many probably still would, but i wouldnt connect a small oven flex straight to the cooker 32 amp circuit anyway if connecting up an oven that has a 13 amp plug type flex on it.

That would not have caused the burning problem here though, that cable may have originally been like that, as the hob terminals dont seem burnt in them photos.

M cebee

a bit of heat resisting 3*4 flexible would do the hob


i reckon the small flex on the oven connected to the 32amp protective device

is prob no big deal-as the oven load is fixed

similar logic applies on 13amp appliances that use a 3*0.75 flex

the protection is just short-circuit afaik

Bruthal

Its probably never going to be a problem having a 2.5 flex on the oven straight into the 32 amp circuit. Or even a 1.5

It will still be a small flex with a 32amp breaker behind it though.

Even the internal wiring of cookers is 2.5, with 32 amp circuit, but at least they are inside a steel casing.

3x4 flex is grand, but an oven with a flex already fitted wont have people refitting a new flex.

Appliances with 0.75 flex would have a 13 amp plug alright, but any that take the full 13 would have 2.5 flex, 0.75 would be very low wattage items like lamps, radios etc, and are supposed to have 3 amp fuses.

But your right, very little risk with oven straight in, but if its a small flex to it, i would have something on it.

I was going to ask what you think yourself:D

Bruthal

Anyway creedp, you could just cut off the damaged looking bit and re connect as it was, and that will clear the melted bit of the cable.

M cebee

robbie7730 wrote: »

Its probably never going to be a problem having a 2.5 flex on the oven straight into the 32 amp circuit. Or even a 1.5

It will still be a small flex with a 32amp breaker behind it though.

Even the internal wiring of cookers is 2.5, with 32 amp circuit, but at least they are inside a steel casing.

3x4 flex is grand, but an oven with a flex already fitted wont have people refitting a new flex.

Appliances with 0.75 flex would have a 13 amp plug alright, but any that take the full 13 would have 2.5 flex, 0.75 would be very low wattage items like lamps, radios etc, and are supposed to have 3 amp fuses.

But your right, very little risk with oven straight in, but if its a small flex to it, i would have something on it.

I was going to ask what you think yourself:D

i would follow the manufacturers instructions anyhow

i normally separate the oven and hob on new work-rather than connect them together on the larger ocpd



on the 13amp appliances the flex is sized to match the load-as the load is fixed

ie: the toaster has a 13amp fuse but only a 6amp(0.75)flex

Bruthal

It means the flex is not properly protected by the fuse in the usual sizing way though, even if an overload is unlikely, made even more unlikely by the RCD if the item is plugged in, as overloads on elements can only really be caused by an earth fault in it.

I mentioned all this stuff before when others come out with that "fuse protects the cable, end of" statement, although i didnt realise the toaster cables were that small.

A 13 amp fuse wont protect a 6 amp cable much, even though its unlikely to ever have to, (although they are of more benefit plugged into a ring circuit for short circuits) so manufacturers are just putting the fused plug in so they can be sold here, with no need to have a flex up to the rated fuse size, because many other places they are sold, no fuse is needed at all.

So if i was myself connectiong the above oven to the cooker circuit, i would fuse the item to the flex rather than going by what manufacturers do with other appliances even though the load is fixed to below the flex size.

Seperate for a new job is a good idea alright.

M cebee

yes i remember the plug thread

only lately i learnt this

it seems the 13amp fuse protects the appliance cord in the event of short-circuit as overload is unlikely on the fixed load

maybe not in all cases-i don't know

Bruthal

Yea your the first i seen mention about the fixed load thing here, i have mentioned it before in person with others talking about the plug fuses, that overload is unlikely. Never noticed the likes of a toaster flex was so small though, thats another new one, i assumed it was at least 1.5 flex. Looks like it is indeed smaller than that.