Cooker Circuits Diversity, 15kW load, 32A circuit breaker.

[@Thruxtonite]

Excellent, informative video thanks. We’re about to have our kitchen refitted and are swapping to an induction hob from gas and a number of kitchen suppliers and electricians have told us that we’ll need a dedicated 32Amp supply from the consumer unit even though we have an existing 32Amp cooker circuit with only our single electric oven on it. One suggestion we were given was to put the new Induction hob on the existing oven circuit and then add the 3.2kW oven to the kitchen socket ring main, hardwired. Now I’ve watched this and learnt about Diversity I know that both the new 7.35kW induction hob and 3.2kW oven (20.77Amp total) can be run on the existing 32Amp cooker circuit . Thank you

[@shadow-Sun]

Your method of teaching is absolutely first class every word you use has value and is not in the least superfluous to your explanation when setting out your examples etc I really do enjoy these mini lectures and the skill with which you impart your subject matter . By far one of the best you tube channels out there bar non on electrical matters . Thankyou for your effort on this channel which is reflected in your number of loyal subscribers .

[@millomweb]

"every word you use has value and is not in the least superfluous" - oh yes some are - when he's in dry humour mode - which occurs a few times in his videos.

[@TheChipmunk2008]

In this video, paraphrasing: "if you're the type of person who puts it in and just uses it for 20 years without cleaning behind it, this does not apply to you" (Which from my experience seems to be most people!)

[@richardwash6678]

Totally agree with every word!

[@Mark1024MAK]

TheChipmunk2008 - what’s this strange thing you speak of “cleaning”? 😂

[@jackalek]

I can only second that! Also very clear English and good pronunciation which really help if someone is not native speaker.

[@c4jax]

Thankyou for the clear explanation and break down of the explanation into simple steps. The hidden humour of cleaning behind a 20 year cooker made me chuckle too.

[@SJM689]

My apprentice was talking about you today, said you were better than her college tutor. I do believe she learns far more from you than college....so thought I'd see for myself and I don't think she's wrong.....keep up the good work

[@GazzJ82]

I have lost count of the times that someone has called me in to install a cooker and the salesman has told them it will need a 50a supply and everything upgrading. Haven't needed a supply greater than 32a yet. :) Great video as always.

[@musashigundoh]

The manual for my Gorenje cooker states that it requires a 32A or 40A breaker ("depending on type", so I assume 40B or 32C?) and a 3*4mm2 flex cable. But I have a C40 breaker on this circuit, so I used a 3*6mm2 flex cable.

[@Dailymailnewz]

When I studied a long time ago it was always 60 amps- things have changed allot since...

[@gloomyblackfur399]

I wish we were more sensible in the US. Our code mandates a 50 amp breaker and 6 AWG (16mm2) wiring. And since we have split phase (the electronics on a 240v oven use 120v), that means four 16mm2 wires (line 1, line 2, neutral, ground). Colossal waste of copper.

[@GazzJ82]

@@gloomyblackfur399 Thats crazy. When we have a 3 phase and neutral supply we are aloud to have a reduced neutral if it can easily be proven that little current will be flowing in the neutral conductor.

[@bartman58]

I honestly think they should get you to write the next edition of the wiring regs John👍🏻

[@mb-electricalservices]

Amen to that.....

[@w415hyz]

Agreed. And once the regs are confirmed and finalised, that’s that!!!! I’m fed up of regs changing, you never know wether you’re coming or going. The only reason the regs change is for some clown to justify his/her job: * walk into building* *hmmmmm..........what nonsense can we make up today just to piss everyone off??* *ohhhhh, I know,*

[@cocoino2307]

@@w415hyz if they didnt come up with new ass rules they would be out of job, so why you think they do it

[@bartman58]

A couple of points in this video I have had a disagreement with my assessor over the last couple of years......he nearly shat when I showed him this😂😂

[@Sergey3023]

@@w415hyz You forgot about £ that they earn from sale of these books😁

[@NOELTM]

Really helped me with my kitchen hob/oven install and working out the load with diversity applied. Thank you.

[@cathalwright5611]

As a building control officer with no electrical training I am so impressed with the explanations given in your videos. I very much appreciate your time and effort, you have explained clearly with clear understandable examples. I am not an electrician but feel more confident in my role with regards to understanding electrical work in domestic properties. Thank You .

[@francisexperience]

Your presentation are the best I have even seen, clear precise and easy to understand, nothing short of excellent Thank you.

[@ThePa1ch]

I love this video. Thank you. It's so frustrating seeing people on forums advocating 10mm2 cable with 45a MCBs for cooker circuits without any rationale.

[@spencerwilton5831]

P JD You need to come to mine for a full Christmas dinner! Three ovens, eight rings and warming cupboard going full tilt. If the lights don't dim across South London it means I have forgotten one of the veg.

[@gavkit]

@@r.h.8754 22amps

[@johnburns4017]

@@spencerwilton5831 The old Christmas dinner fear. They will not be all on at once as thermostats cut in.

[@Speedkam]

@johnburns4017 if they are all on, how long until it trips?

[@keithhowes402]

As an old spark I wished I'd have had you as a lecturer back in the late 1960s when I was at college

[@mikes6844]

This has been a refreshing albeit vindicating video for me, fantastic/straightforward and common sense view on the difference between the use of 4mm and 6mm size cable. Thank you John. 👍🏻👍🏻👍🏻

[@SqwarkParrotSpittingFeathers]

Very informative as usual. I shall be placing on any consumer units installed a notice saying "in compliance with JW regs", as JW regs are more authoritive and clearly explained than the On Site Guide and BS7671:2018, lol.

[@ipmoroca]

I did find your channel in the past with great explanation, but this just reminded me of the effort you go through to break down things! Keep up the great work!

[@TupmaniaTurning]

Love this channel. Always something to learn and I’m not a sparky!

[@maciejtryka9145]

One of the best videos on domestic cooker installation, so many sparkies don't understand it and panic when coming to install electric range cooker- just dividing W/V and coming up with 16mm2 cable, not taking into account thermostats and energy regulators which allow for use of diversity factor. The way its presented is so simple that every layman would understand. Well done Sir!

[@leea1988]

This has answered a question I've long wondered about. You're a champion, thankyou!

[@yvonfem]

Brilliant John you have a fantastic way of explaining things I'm not a spark but I always find your channel entertaining and I actually understand it thank you

[@ApacheSenzala]

Oh my god I wish I had seen this before so helpful and reassuring love your matter of fact tone and the clear and concise math

[@Oldfellas1]

John, greatly explained, thank you. Found your channel by chance and now wonder how I ever did without it .

[@4544481]

For me, this is the best site for electrical know how. I very much appreciate your knowledgeable, helpful posts. First class & very thorough👍

[@kevinpickett7249]

So well explained and as previous comments anybody could learn with your technique of teaching

[@samplumbe3288]

Love your dry sense of humour. Great tips. Thanks

[@ronalddobson3130]

Thanks again, John. Not the first time you've saved me money and educated me.

[@RJSElectricalCheshire]

Great video as always John. I've always installed a cooker circuit on 6mm because that's the way it's always been done. I've always got 4mm that rarely gets used and keep buying rolls of 6mm. Time to start using up the 4mm me thinks 😃😃

[@johnburns4017]

Some put sub CU's in kitchens to keep all kitchen appliance isolation switches at one convenient point. Grid switches can do the same with switches available with words like _cooker,_ _fridge,_ etc, on them. A small CU using double pole mcbs is cheap and quicker to install. About 15 years ago MEM made a kitchen specific box and isolation switches with the switches labelled _hob,_ _fridge,_ etc. I have not seen it sold for a long time. Where all heavy appliances are in the kitchen (even an immersion in a kitchen cupboard), I have seen a heavy cable from the main CU at the front of a house run to the kitchen at the back of the house in a sub CU for the kitchen. It reduced the volume of cables needed simplifying the installation. Quicker to install and local isolation of the appliances at the sub CU.

[@lukwal3514]

In my opinion you do best tutorials on British you tube about the science and practical things regarding electric work. Well done👌

[@viktorskostiks770]

Can find out more from your videos than from the college. Many thanks for your work.

[@SME_Ste]

Love it John many a time i’ve been doubted when installing 4mm for cooker circuits when installation methods allow. I’ve lost count have many times fellow youtubers are pulling in 10mm supplies for hob/oven combos, which is ridiculous.

[@musashigundoh]

Well, a 10mm2 cable won't hurt anything... Except your wallet and your finders, I guess.

[@TheChipmunk2008]

10MM is a BEOTCH to deal with in any normal accessory box. I agree with the person elsewhere in this comments section that says it doesn't belong in a domestic environment except as a feed to a specific outbuilding or second fuseboard. In which case you're not going to be terminating into an accessory box.. The number of electric showers that have exposed primary insulation outside the box either in the wall or roofspace because there's no physical way of doing otherwise even with a 47mm box... is countless

[@und4287]

10mm is overkill, unless they have multiple cookers

[@nafizkhan7748]

6mm is the correct size if the cables are partially covered in insulation. You got to derate the cables based on installation method.

[@thomasbonse]

Is there not a regulation concerning box fill? I know the US version has a section specially addressing box fill and minimum volumetric dimensions.

[@4addevelopments139]

Yet another fantastic video for a learner like me. I didn’t know there was such a thing as dual outlets for ovens/hobs.

[@colinhubbard4826]

Often we don’t know what the builders will do after our 1st fix. Some jobs the ceilings/floor joist voids are left empty and some get pack with insulation. We tend to use 6mm to cover ourselves on this basis

[@MH-sf5ml]

Here here. John is an example of relying on books rather than foresight. I still remember his video on why it was pointless to replace rewireable fuses with the push-in resettable style. Except for the fact that a lot of pensioners can't afford to get a new dB and a full EICR.

[@cocoino2307]

you should always future proof it aswell, we dont know what kind of powerfull cookers we might get in 10 20 years

[@heiltd1286]

Eloquently and clearly elucidated as always.

[@markburgess2327]

Excellent explanation, thank you. And I enjoy your wry sense of humour.

[@chrisrhodes1127]

Diversity Perfectly explained !

[@gibbodive140]

I have the utmost respect for you and have watched many of your presentations. They are clear, concise and informative, far more so than most training courses I have attended. However on this one I (and some others by the reading below) would like a little further clarification :- Agreed regarding mutating ovens/appliances. However if the wiring were rated at less than 32 A within the the appliance, would it be adequately protected by a 32A overcurrent protective device ? If there were a short circuit within that wiring, would it be adequately protected by such a device ? Non compliance in any respect from manufacturers requirements/specifications sounds rather foolish to me, potentially resulting in a tricky situation if there were a significant incident ? Why expose oneself by non compliance with all relevant standards, however small. I am not being critical, but would appreciate a greater understanding. Thank you

[@jamesdevlin3892]

I'd be interested too. Some manufacturers specify a 16A breaker. On a recent job I has two 3kW ovens that specified a 16A breaker. I ended up putting them on a 32A breaker, to a cooker isolator, to two 13A fused connection units to try to comply. Easier to whack them both in a cooker plate. If there was an accident like a fire that started on the cooker circuit, I wonder what the verdict would be.

[@literoadie3502]

Great video John. I recently installed a cooker circuit, but never gave the cable size much thought and just assumed 6mm cable was a good choice, and certainly seemed to be the norm. I now realise 4mm is perfectly adequate on a 32A MCB. Thanks

[@electricery]

As usual, an excellent video John, Love the way you say 6mm is installed just because some electricians insist on doing things the way they’ve always been done. I find the same applies to bathroom lights, why do they automatically get installed with pull switches or with plate switches outside the room when you can often install a plate switch in the bathroom as long as its out of zone 1 or 2, also ring circuits get Installed just because they have always done it that way

[@markgilder9990]

Myhippocampus I tend to do rings for utility and kitchen, radial circuits for remainder of house. 👍🏻Just makes sense.

[@jaydenplaysguitar3896]

Rings for utility and kitchens are a must in my opinion. Fair power distribution across a circuit is an important factor to consider when designing.

[@electricery]

@@jaydenplaysguitar3896 if only people would actually design rings with "fair power distribution across the circuit" trouble is it never happens, rings are always installed in the easiest, shortest route from socket one to the next rather than considering how much load might be on one leg, which is normally the dishwasher, washing machine, kettle, oven, microwave all next to each other on the same leg. SparkyNinja did a good video on balancing rings and loading a year back

[@jafarsunny1762]

J W you are the star of the you tube electrical video. Need more from you.

[@williamstewart1266]

top video the whole of the uk needs to protect this man!!

[@nervousfrog101]

Thank you so much for this video. I was looking to get my dual fuel range cooker replaced with a fully electic one so I wanted to get my head round what was needed before getting an electrician to quote. I started looking at cookers online and they were quoting max powers of 15kw but only needing 32A breaker etc which just did not add up from my basic understanding so thank you very much for explaining.

[@sidwainhouse]

I find it really helpful that a lot of manufacturers are giving the ratings now in kWh rather than kW, very helpful when designing a circuit...

[@robholding]

Exactly what I need to know. thank you. Excellent explanation!

[@sankyeat]

Great Video! Please keep making videos like this they're amazing.

[@Event13]

Exactly what I wanted to know. I'm a time served installation electrician with 40 years in the game and although I don't do much domestic I always thought a cooker switch was supplied with a minimum of 6mm. As John mentions this is a hangover from the old rewirable fuse ratings. Excellent explanation proving you're never too old to learn but I'd probably still run 6mm over any kind of distance just in case of containment or lagging etc or maybe they wanted some sort of unusually high rating oven. Saying that have you seen the price of 6mm T&E recently? LORD. It's very tempting to do in 4mm but it feels so wrong.

[@Observer-hl3mm]

Method C means clipped directly, which is unlikely to be found in a modern kitchen. Hidden in a conduit inside the wall (method A) is far more usual. Which corresponds to 6 mm2 at 32A MCB.

[@lucapuzzoli8363]

Thank you

[@Михаиллеви]

Method A is for an insulated wall. Method B is most common for wall cabling.

[@richardwash6678]

Brilliant video John, as always. Love the way you explain things. 👍

[@Watan-jan]

Thanks John for producing easy understanding video, I would be lost with out your explanation. Thank again

[@grahammchardy9249]

I can now think of quite a few small domestic properties with 2 cooker circuits. Seems a pointless waste of copper. Thanks for clearing up the misconceptions.

[@KINGWD0110]

Very informarive video, no need to waste money on larger cables for 2 MCB's =). Thanks,

[@johncope6243]

Great video with well explained detail. Helped me [DIY] plan my kitchen electrics ready for sparky. On the point of detail: six square millimetres is six times six which equals a surface area of thirty six millimetres. six millimetres squared is a surface area of six millimetres ;) (at least as I understand it?)

[@tomporter6182]

That's the wrong way around surely... 6mm squared is 36, (as in 6 squared = 36), 6 square mm is 6 square mm

[@jazbell7]

Interesting, in the USA we call those combined units "electric ranges" or "electric stoves". Typically supplied with 240v @40A over 8 gauge (approx 8 square mm) wire.

[@kpanic23]

Here in Germany you're not allowed to pull more than 20A from a single phase (Schieflastverordnung, "asymmetric load act"). So our Cookers or hobs are usually supplied by 3x16A three-phase in Y configuration, so 3x230V. Cable is 5x2.5mm². We don't have isolator switches, just a cooker outlet (Herdanschlussdose) with screw terminals, from which a flex cable runs to the cooker. To isolate the appliance, you just flip the breakers. If you have an oven separately from the hob, it usually gets its own 16A breaker. Single phase installations get more and more rare, three-phase has pretty much been standard for the last 50 years. Even the smallest flats and apartments usually have three phase power. You can usually bridge the cooker's input to supply it with a single phase, but you're then limited to 20A. Although they're still some really old installations, where the cooker has a 25A or even 35A D-System fuse (slow-blow).

[@millomweb]

"Stove" is used in England for said item but is an old-fashioned term for such things - and tended to be more used with gas - hence 'gas stove'. The enamelled finish on such appliances being commonly referred to as 'stove enamel'. Here, a 'range' is a similar thing but on a significantly larger scale - 3,4 or more ovens and plenty of places for heating pans or boiling water. These were developed around a solid fuel fire (wood burning, coal or coke) and were likely known in America in its 'early' modern days - and not surprisingly, the name is still used for the smaller 4-burner 'cookers' that are common in England. One thing to bear in mind, if you compare photos of equivalent cooking devices between US & England, ours are always much more compact due to our more compact style of 'average' homes. While a US 4 hot plate cooker may well have space for pans between the hot plates, you will not find this on typical appliances in England - where in fact lage pans placed on adjacent hot plates may well have to be touching each other to centre them on the hot plates !

[@Zenmelin]

@@millomweb Similarly in Wales and probably Scotland and Northern Ireland too! 😉

[@millomweb]

@@Zenmelin I'm now using 'England' instead of Disunited Kingdom.

[@tonyjones9442]

@@Zenmelin In North wales the word for cooker is 'Popty'.

[@jasonlaverty76]

Good explanation and I just wish more kitchen designers would understand this. Now what about COMBI OVENS JW? These are generally 16A rated appliances and I have seen them on a 13 amp plug many times. Should Diversity 0,725 be applied or 10A plus 30%? 11.6 A or 14.2 A

[@supersparks9466]

Nice vid JW , one issue is 4mm can cost as much and sometimes more than 6mm given it’s unpopular size.

[@seandempsey9396]

Fantastic. Very well explained Clear and easy to understand. Thank you John.

[@robsparks1993]

Great work JW!!

[@simonhowle6576]

very very clear explanation. Thank you John.

[@cambridgemart2075]

Unfortunately that's what our electrician did, but he failed to note our split level oven has a cleaning mode that runs all the elements for 90 minutes, bringing the oven up to 470C; without fail, it trips the breaker midway through the cleaning cycle.

[@jwflame]

What is the total load of the oven? To trip a 32A circuit breaker in 45 minutes would require well over 40 amps continuously, which would be a heating load in the region of 9-10kW, which seems grossly excessive for any oven.

[@loosecannon5813]

6mm cable is acceptable for 40A MCB (clipped direct)

[@cambridgemart2075]

@@jwflame I dug through the manual and it states it should be fused at 16A and has a max consumption of 2900W. I'll have to get a clamp meter on the supply cable to see what it is drawing in cleaning mode.

[@millomweb]

@@cambridgemart2075 Something fishy there then - if rated 16A and tripping a 32A breaker ! Faulty appliance ?

[@TheChipmunk2008]

Has he replaced a traditional oven with it? (they often used a 13A plug onto the ring mai...err ring final ;) ) Kitchen companies are AWFUL for that... sell a customer a self cleaning oven without telling them 'you're gonna need an electrician install a dedicated 16 or 20A circuit. If it's on the same ring as the rest of the house (often in older properties without a dedicated kitchen ring) a constant 2.9Kw load might be competing with other appliances.

[@MrPDawes]

Having just installed an induction hob to replace my gas hob and had to run a new cable for it, am quite happy I used 6mm sqr. Cable is run in trunking between brick wall as this was the only way to get power to it. Very happy it won't be heating the wall up. I do have cavity wall insulation though so needed to uprate the cable.

[@manchestercity01]

Top job well explained and nice and calm while showing each example. This has to be my go to site cheers

[@ap06smart]

Thank you John for the comfirmation on Cooker Circuits, just what I thought.

[@winstoningram7713]

Awesome video as always great teaching methods very easy to listen to , Thanks JW 👍

[@Ralphs-House]

Thank you John. Wonderfully informative. As always.

[@andrewforsyth4799]

Hi j, really like your channel its very informative, just come across this older vidio of yours which i do remember, could you explain how the newer iet brown book now reference's this same model regarding the 3036 fuse . They've changed the book because of your teaching ,,brill!!

[@fargogemini694]

John does Fred flintstone know you’ve taken his cookers etc

[@tarassu]

I wired my cooker with 1.5mm2 cable. 4 tops and one oven with grill. Well.. MCB was 3xB13A. Works perfectly.

[@mikeZL3XD7029]

Bugger!!, That is very sage advice John, I've been un-necessarily installing 6mm² cable to free-standing ovens over here in New Zealand, on a 32A breaker. Oddly enough, we have a 4 pin socket-outlet here, that I've never seen used anywhere else in the world, it may be possible it is used in Australia. Thanks for the great video.

[@adamdavis2274]

When choosing the flex cable for the appliance from a outlet plate for a hob or built in oven would you use the same diversity , the first 10amp then 30% of remaining load .

[@planetconker1104]

That's brilliant, thanks a lot. I dont suppose you could do a video on testing a cooker installation once the cooker has been installed please?

[@gapster77]

I have a question regarding 4mm radials in T&E; In a Warehouse I was going to pull a 20A Radial in 4mm T&E, through Metal Trunking & then dropping down a wall in Plastic conduit, the load being a Twin Socket outlet. I did this in 4mm as I was sure a 2nd or 3rd outlet would be requested by the client at a later date. The total length of the Radial was currently 15m, out of interest I checked the onsite guide to see how far this circuit could be extended if I wanted to add another socket at a later date. I could not find an answer, it lists 2.5mm and 6mm ran in such a way for Radial and Ring circuits but 4mm isn’t covered? It puzzled me, and I started to consider the size of the CPC in comparison to the Live conductor, in 4mm the CPC is 1.5mm, which is relatively small in comparison (incidentally I believe this is the same size ratio for 16mm cable?). Is this why this cable size isn’t considered in the tables? What are your thoughts on this cable selection, and how far could it be ran as a 20A radial for socket outlets? (PME supply) Whenever I’m party to a conversation about domestic installations, with Radials Vs Rings being used I consider the 4mm T&E with its 1.5mm CPC and think maybe they should have a 2nd Variant of 4mm with a 2.5mm CPC specifically for Domestic Radials? ...I’m very likely overthinking this though :)

[@jwflame]

20A 4mm radial is on page 70, maximum length with terminal load is 69m. More if the load is distributed.

[@gapster77]

John Ward Thanks! I did call the NIC, and they couldn’t help me?

[@Wilkkid1]

Great video as always John 👌

[@anthonyloftus1236]

Brilliant. I know the theory of electricity but am no electrician. Built in oven is kaput, wife would like the gas hob replaced as well. Does this mean ripping up the kitchen to provide all the extra power? This video answered all my questions. Nice wee bit of humour too.

[@agostinomarano]

Hi John, i have a 4 ring induction hob with a Connection Rating 4,600 W and a separate oven with a Connection Rating 2,990 W. i have rounded them up to 5kw & 3kw giving me a total of 35A once i apply diversity (no 5A for socket) i get a grand total of 17.5A, does this sound correct? i already have a 45A cooker switch with a 6mm² t/e fitted at the oven location on a 32A MCB. also your channel is great i learn so much & love the way you explain things. thank you for your time.

[@LakeNipissing]

Here in Canada for most cookers with four element stove top and broil/bake oven, the circuit would be 240 V, 40 A with cable size 8/3 which works out to just 3.25 mm... Looks like the British Standard is strict for heavier cable, at 4mm with only 32 A. Electric clothes dryer circuits here are 240 V, 30 A with 10/3 (2.59 mm) cable.

[@jwflame]

Uk cables are sized on cross sectional area, not diameter. 8AWG is equivalent to about 8mm2 4mm2 as in the video is approximately 11AWG.

[@LakeNipissing]

@@jwflame Thanks for the reply!! As if it is not confusing we use AWG, they also use diameter in mm , instead of mm2. Keep up the great, great work, JW !

[@allezvenga7617]

Thanks for your sharing 👍

[@AntonyoKnight]

16:30 Can you please help me? I have been searching in the 18the Ed and On-Site about the flexible cable but all I can find is the " 521.9 (Selection and Erection of Wiring Systems) Equipment that is intended to be moved in use shall be connected by flexible cables." And of cource in Definitions but that's a bit useless. Should I use Table 4E2A 3 core 4mm2? Thanks

[@johnburns4017]

A 4mm cable with a 32A mcb at CU. A hob and oven to be connected. A hob can be connected directly to the 4mm cable. Fine. As you said, a 3kW oven will never draw more than about 13A, unless in a fault situation. So, the oven can be plugged into a 15A fuseless round pin plug and socket which is off the 4mm cable, behind the oven. 15A round pin plugs are still legal on radials on directly on a final ring circuit (can be on a radial spur circuit off a final ring). Using a normal square pin 13A plug gives an inaccessible fuse. Fuses ideally should not be inaccessible.

[@tonylynessable]

Hi John. Great content as always. Can this rule of diversity be applied if trying to figure how many amps a house would generally draw? Taking into account all appliances etc etc..

[@Adywebb123]

Brilliant video as always well explained. I have recently been asked to work out an electrical load for a new build property. Not something I normally do . It’s has 3 floors 3 separate flats, each flat consists of a cooker circuit, 10 kw shower, 2 small rings mains and single lighting circuit. It’s has a three phase supply coming in, how do I work out each flat and total for all flats. Hope you can help. Thanks

[@jwflame]

Covered in this older video: kzbin.info/www/bejne/jaKTpoJ6rtWUfas and also see Appendix A in the on site guide.

[@M8d9R]

Hi John, I'm a new apprentice/improver, and enjoying your videos, thanks for making them. I asked the electrician's at my employer about 4mm cooker supplies. They were of an opposite opinion - that cooker supplies should even be on a 10mm! This is on account of, as soon as the cable goes into a loft, god knows it'll be buried in insulation, going through walls, enclosed in oval conduit conduit in walls, or worse half the time - due to poor original installations. Is it the case that for a 4mm cooker supply, the reference method has to be C, literally at every point of the cable run? Which is often unrealistic in many properties. If the cable goes down through oval conduit in a wall, does that mean straight away the cable loses its ability to lose heat and a 6mm immediately becomes necessary. Cheers, grateful for your videos, they are very useful to keep pushing my learning. Matt

[@justifiedfreelybyhisgrace1779]

My inlaws are getting a new large range style cooker thats induction and is about 15.5 kw potentially. I believe this is on a 6mm cable and a 32a mcb (although) im yet to check so this video has eased my fears for them somewhat

[@StewSims]

Brilliant video thanks. We are putting in a new cooker (induction hob and double oven rated at 10.7kW) and have been advised by an electrician that the existing 32A MCB needs upgrading to 40A and existing 6mm cable from CU swapped with 10mm! Doesn't seem right to me based on the diversity calculations and would involve significant works. The wiring is fairly old but all tested recently and I don't see why we should have to 'upgrade' it. Might seek a second opinion from another sparky.

[@jwflame]

32A will be fine for that. 6mm² cable can be rated to well over 40A depending on how it's installed so probably wouldn't have needed upgrading even if the MCB was changed to 40A. An induction hob will use less energy overall compared to a conventional electric. Some do have higher power boost settings, but those are only used for short periods so won't be a problem.

[@HereForTheMusic-h5o]

Great video and information as usual!

[@johnburns4017]

Most cooker circuits I see have 6mm cable and a 40A mcb to protect the 6mm cable.

[@kevvywevvywoo]

I've just downloaded a random installation sheet for a hotpoint 4-ring freestanding uk cooker and it says it must be provided with a 45A supply.

[@johnburns4017]

@@kevvywevvywoo To keep to guarantee, you will need to get a 45A mcb. If not available then apply the diversity factor.

[@malcolmkenward2663]

Excellent video thank you. I have an historic 6mm connection to a double oven (mcb’s now) and a gas hob. The oven is being replaced by a single 15kW and the hob by a 7.5 kW induction. They will be on opposite sides of the kitchen, about 3 metres apart. Your video suggests to me that I could fit a junction box to the 6mm cable (access is easy) and then add an extra 4mm outlet (spur) for the hob, both going to required connections and switches, instead of installing a whole new radial circuit. Both cables will run in the void under the floorboards in a Xictorian house. Would this comply with the regs?

[@malcolmkenward2663]

Can’t edit. 3kW oven!

[@jwflame]

Yes, doesn't matter whether they are in different locations or not.

[@LB-gr5se]

Hmm isn't reference method 100 the usual method in domestic households? Theres always insulation in the ceiling and generally the cables are clipped to the wooden joints or floating through drilled holes and 100mm of insulation.

[@ginandtreats8556]

Thank you for a very informative explanation.

[@jonbaldwin]

I've got a single oven plugged in to a standard 13A socket outlet. My hob is gas. Is there any point in having a cooker circuit installed when we next redecorate or, if it's only likely ever to be a single oven, is that overkill? Never had any problem with the usual socket circuit overloading.

[@jwflame]

If that's all you will ever have there then no need for a cooker circuit. However electrical installations are there for a very long time, people change their mind and it would be sensible to install one.

[@loosecannon5813]

I would never recommend plugging an oven into a 13A socket. Seen plenty of burnt out plug/sockets to cement that. A fixed connection everytime.

[@millomweb]

@@loosecannon5813 Why do they come with a plug already fitted then ? In our case, a combi microwave/oven/grill.

[@millomweb]

We had a gas cooker but the house was wired for electric. Our Cannon gas heap of shite got electrically worse and worse with age - but newer gas cookers seem to have even more electrics on them - so to avoid all this naff electronics, I got a.... ...induction hobbed electric cooker - Belling - which apart from the shite knobs breaking, has been generally great. I'm a fan of induction (as is Carol Vorderman) and would highly recommend them. My suggestion therefore is fit a cooker circuit while it's relatively easy in case you change your mind later in life about using gas !

[@Vtlkvtlkvtlk]

No mention of isolating switch? It on not in regs?

[@neilanderson394]

The problem is when you carry out a EICR , you have no idea how the cable has been ran in , I’ve always aired on the side of caution, reference method C mentions capping but I’ve seen conduits being used as mechanical protection. Plus you would have to gauge the required depth. If I seen 4mm on a 32Amp MCB I would pick that up unless I was totally sure of the reference methods used. If you’ve installed it then great no problems.

[@chrisswift1834]

It's also been ingrained in my head to use 1.5mm T&E lighting cable....1.0mm is fine with all the LED lamps now available.

[@mwbg]

Thank you. You've answered everything.

[@Prince-ep8pv]

Hey John, Great video! Have a quick question though. In the case that there is an individual oven and separate hob, would you take 10amps plus 30% of the remaining load for both separately and add them up, or do 10amps plus 30% combined? Thanks a lot for the great content John!

[@jwflame]

10A plus 30% of the combined load - exactly the same as for a cooker. The fact they are in two separate pieces doesn't make any difference to the electrical load.

[@millomweb]

@@jwflame I see no reason not to connect built in ovens to a ring main rather than a dedicated 'cooking' supply. Seems that's the norm with combi microwaves/oven/grill.

[@Jamal_Tyrone]

@@millomweb I think it's for maintenance, so if you're working on the oven you don't have to turn off the ring or any other circuit.

[@boblewis5558]

Diversity SHOULD be understood by every sparkie. However ... In our LAST house, diversity at family gatherings - Easter, summer, and of course Christmas was ZERO (4/5 ring hob with halogen double ring, double oven)! It drove my wife (and me) NUTS as she would be part way through cooking and the 32A mcb would trip EVERY time without fail when she turned on the top oven to cook parsnips etc! NOW, it's a complete non issue as the double oven ONLY is on a 32A breaker, but the hob is on the kitchen ring ... it takes barely 1.5A! ... It has a "sensible" fuel for cooking ... GAS! I NEVER understood why anyone EVER thought it was a good idea to burn fuel (usually the exact same gas as delivered to your gas cooker!) to produce heat to produce steam to turn a turbine (MASSIVE losses), to generate electricity (MORE losses), transform the electricity (yet more losses x2 MINIMUM!) JUST so it can be delivered to a property to turn it back to heat! Insanity on a stick All the time, THROWING AWAY 60% of the original heat energy! ALSO, large modern, all electric 6 or even 7 way hobs on triple oven ranges are way more common these days and often need 2 x 32A breakers and 4mm² for each would be OK but only just. Induction hobs also consume a lot more but are more efficient generally, but still may need two feeds or a 40-45A breaker and suitable cabling. Personally, I'd rather see installations made using 6mm² simply to obviate the need for otherwise unnecessary "construction" work when someone decides they want to remodel their kitchen and switch to all electric from an old gas/electric. Worried about an extra few quid on a SINGLE run of 40 feet of 6mm² v 4mm²!!?? WHY? Who benefits? The consumer? Err NO! NEVER! Plan for the future, save the consumer a fortune on having to rip their place apart JUST to lay a NEW, replacement 6mm² costing just an extra £20 or so if done up front, or potentially thousands if done later!!??

[@TheChipmunk2008]

One case in the US I remember where the oven element DID transform to something that randomly demands more power... 240v oven element shorted to ground somewhere near the middle (which being a centre tapped 120-0-120 system didn't have much effect). No GFCI (rcd).. eventually water got in during cleaning, and began to saturate the mineral insulation... long story short, it still worked but the customer said it was sparking and kept getting brighter and brighter in the bottom of the oven. It''d burned down to about 1/3 of its length on one leg (the other was open circuit)... and was pulling about 30 amps on its own from 120 to ground. Quite scary as back then stoves used a 3 prong plug and grounded via the neutral, so any volt drop in the neutral was being reflected back onto the frame!

[@johnburns4017]

So are you saying there should be overcurrent protection on ovens, which John says there is no need for?

[@TheEulerID]

One of those infamous NEMA 10 connectors with the chassis connected to neutral. What could possibly go wrong? At least it's only 120V to ground...

[@TheChipmunk2008]

@@johnburns4017 in the UK absolutely not. In the USA at the current time absolutely not. It was an anecdote vaguely related to the topic.

[@TheChipmunk2008]

If your element goes that thermonuclear these days in either country something is going to trip before it gets to that point

[@TheChipmunk2008]

@@TheEulerID indeed the very concept horrified me when I first made the move to the US

[@rossmurdoch7870]

Hi John excellent explanation once again

[@darrenbanton8929]

Respect John👊🏾 thank you very much

[@michaeltb1358]

Cooker switches used to include a 15/13 amp socket which would have increased possible load dramatically.

[@markluke7528]

Hi John please explain 2x 4 ring induction hobs side by side and 2x ovens side by side as I have big family want to install in my new kitchen

[@spiderjuice9874]

4:05 But is "six millimetres squared" the same as "six square millimetres"? Surely, "six millimetres squared" is (6mm)^2 which is 36 square millimetres, which is 6x larger than "six square millimetres" - please correct me if I've misunderstood.

[@jetg2111]

You've misunderstand... The "squared" applies to the millimetres in both instances, not to the 6

[@spiderjuice9874]

@@jetg2111 OK, thanks!

[@richardlang2185]

Dear John, you are best of the best. I have question about 65.217A. If I'm understand correctly, that should be allowed only for one complete unit, probably can be separate oven and hob. If there is two separate units or more cooking appliances installed on one room, circuit of rating not exceeding 50A, 11.5kW is apply as per Figure 4.4 Electrician's Guide P67.

[@terryallen3231]

Excellent educator