Previous owner mayhem

[Essex1]

As Essex points out it could well do comply although not the conventional way of doing things Imo (domestic wise any way) but would have to satisfy the requirements of section 434

and 433.3.1

I know it is not 'correct' and I was playing devils advocate but you see my point?

 

[leesparkykent]

I know it is not 'correct' and I was playing devils advocate but you see my point?

definitely. Effectively for want of a better phrase its being back fused as protected from over current by having the FCU. Most commonly seen in factories and the like when they have an overhead busbar say backed up by 400A fuses and 25mm tapping of the busbar to feed a 80/100A switch fuse.

 

[ProDave]

I think the other circuit in the switch is a lighting circuit and nothing to do with the spur from the cooker circuit.

So why didn't they wire the under unit lights to the lighting circuit?

 

[neodt]

The lighting circuit is totally separate, and the only thing drawing power are some low wattage under lights protected by a fused spur, another question that comes to mind, just out of curiosity, is that if I plugged a light into the 13 amp socket on the cooker switch would that be the same kind of thing as running a spurred 2.5mm from cooker switch to a fused spur. By any means I am not a professional, I am just curious and like to know

 

[leesparkykent]

So why didn't they wire the under unit lights to the lighting circuit?

from the looks of what the OP has said probably done because there was no neutral at the switch. Maybe didn't want the distribution of trying to get up the wall and across the ceiling to the light position.

 

[poni]

yes I known, normally on short runs, inside mains panels, and bus-bar chambers, and when the runs are longer they are usually protected against mechanical damage, and in an industrial environment      

 

[Rob_the_rich]

it s a 5A fuse fitted in the FCU, Essex is right in that the characteristics of the load past the point of reduction in CSA negates the need for overload protection at the point of reduction (433.3.1.(ii)). Fault protection might be a problem though, but with the adiabatic equation the 1.5mm cpc would probably be enough, and there is a likelihood that the cpc to the lighting circuit would also be linked at the switch, so that could be added, and there might be rcd protection to the cooker circuit anyway. Neodt, is there an rcd in the Consumer unit?

 

[leesparkykent]

yes I known, normally on short runs, inside mains panels, and bus-bar chambers, and when the runs are longer they are usually protected against mechanical damage, and in an industrial environment      

yes exactly. But if its satisfies the regs mentioned earlier then the situation explained by the OP could comply.

 

[neodt]

Yeah there is RCD protection on the consumer unit, I can also understand the chance of mechanical damage between the cooker switch and fused spur, even if the length is just under a meter between.

 

[apprentice87]

OCPD needs to be fitted at the point where the cable current carrying capacity reduces. There are circumstances where it can be up to 3 metres from the point of reduction, but i am too tired to go and look it up or the reg number either!!!!

john...

 

[SPECIAL LOCATION]

OCPD needs to be fitted at the point where the cable current carrying capacity reduces. There are circumstances where it can be up to 3 metres from the point of reduction, but i am too tired to go and look it up or the reg number either!!!!

john...

433.2.2.  (ii)

 

[apprentice87]

Thanks for that!!!!

john..

 

[Murdoch]

Whats the rating of the cooker? If its over 2kw then it should be on a dedicated circuit IMHO

 

[Rob_the_rich]

433.2.2.  (ii)

OCPD needs to be fitted at the point where the cable current carrying capacity reduces. There are circumstances where it can be up to 3 metres from the point of reduction, but i am too tired to go and look it up or the reg number either!!!!

john...

433.2.2 and 433.3 are exceptions to 432.2.1

433.3.1.(ii), is therefore an exception, so no need to have ocpd at point of csa reduction.

Fault current protection is afforded by the RCD. No need for fault current protection to be at point of reduction either (434.2.2) provided it complies with 434.5.2, which is where a bit of calculation is needed 115x115x1.5x1.5= 29756 which should be greater than the I2t of the RCD and probably of the mcb too.

That is assuming that the CU RCD(s) protects the cooker circuit. Neotd, if you press the RCD test button (marked T or test) does the cooker (and the lights in question) turn off? Shut down PCs, iron lungs etc first of course.

Also assuming that there is 2.5mm twin and earth from the switch to the FCU, or does it further reduce to 1.5mm t&e at the switch?

Whats the rating of the cooker? If its over 2kw then it should be on a dedicated circuit IMHO

And what type of cooker (induction hob?) and what rating is the mcb?

 

[neodt]

Would just like to say a big thank you for the overwelming replies. You've all been very helpful. After weighing up the options I'm going to get a sparky in to put a fused spur next to the light switch and connect the live feed from the cooker to that so everything past is safe. I'll lose a couple of tiles but I like waking up to my family in the morning and safety is paramount over cosmetics. Thanks again everyone

 

[NozSpark]

TBH it might be as well to get the while place inspected and tested,,, the recommendation is on change of occupancy or a maximum (to determined by the inspector) of 10 years - whichever is sooner

 

[neodt]

TBH it might be as well to get the while place inspected and tested,,, the recommendation is on change of occupancy or a maximum (to determined by the inspector) of 10 years - whichever is sooner

That I never knew. Will deffo have a look into that

 

[poni]

so I can now install a twin 13A socket on a bit of 2.5 T&E less then 3m fed from my cooker switch , that is going to get me out of so many holes , Life is good 

 

[Sharpend]

Got to be honest poni, with all your years of experience I can't believe you didn't think of doing this sooner !!!

 

[poni]

old dog new tricks

don't do a lot of dom's