Your videos are exactly what I want. I have been looking for a better video about Electrical installation after years of doing electrical installation level 2 with no job.. I needed a refresh and none of the other video was more of practical than this..you doing good job..thanks so much for all this videos..
Advice please. I’ve got a 2.4kw oven which I put on a 13a spur as suggested but don’t like this I want to put it on the main cooker/hob switch. This circuit is on a 32a mcb and 10mm cable and currently powers the 7kw electric hob. My idea is to spur from the hob plate in 6mm to an unswitched 13a plate so they are both on the same switch. I can’t find a problem other than if the fuse blows I have to pull the oven out the cupboard but just wanted to run it past someone. Spark said just put them together but it’s the 13a that bothers me on that idea. Thanks.
It's a great video. The only issue I have is when you added 20.5A + 5A = 25.5A in your diversity calculation ...the answer is 25.5A. It still falls within the parameters. Just a heads up👍
What size of cable would you use from dual cooker connector to the oven if its already has a 2.5 mm and plug top attached can you commect the 2.5 into the dual cooker connector or does it need replacing with 6mm cable
I am working up a belling hob it has come with a 4 core wire. But the wire going to the old hob is 3 core wire. Do I connect L1 and L2 in to a 3 way wago connector. Interested to know
Hi there! Putting new kitchen in now! Has 3 new appliances arrived: Induction hob 6.9kw; Single oven 3 kw and 3.3kw build in Microwave-oven. All seems to be a hard wiring, no plugs! I have 32aMCB and 6mm cable attached with Dual connector unit on the bottom! Has a busy household, so it is possibility what can use all on the same time. i think to switching Microwave oven to my downstairs sockets other 32a MCB through fused switch like you show on video and other two appliances to Cooker Dual connection unit! Under Diversity calculation seems to be enough, but just want to make sure! Please help me to work out if you can!? Your respond will be really appreciated! Thanks in advance!!!
Hi I know this video was posted long time ago, I have a question do you need a RCD in your consumer unit or fuse box?, and also if you put 45A in your cooker switch, when will be disconnected in case of overload if you installed your ciurcuit breaker of 32A ?
in that given diagram, where can I possibly add the cooker hood connection without a plug, or I'll just connect a plug top and into the one of the sockets on the wall? thanks!
In my kitchen I ran a spur from the worktop double socket (on a ring circuit) up behind the wall units to a double socket on top for my cooker hood. I did however have drywall on studs so easier to fish a wire up from behind the socket with no tile damage etc
Read this - 300 mm is the recommendation but it's not a regulation, either for the cooker switch or for the socket near the sink. They suggest a min distance of just 100mm. As there's no requirement for a cooker switch, there's no minimum or maximum distance.12 Sep 2015
That would be determined by how many watts your Ikea oven is rated at. for example if your oven is rated at 3600w (aka 3.6Kw) and the nominal power supply to your house is 230v - then to find out what size cable and breaker you would need you have to calc. the required amps. To do this, you use the formula (Amps = Watts divided by Volts). So for in the example - the Oven is 3600 Watts divided by the supply voltage which is 230 Volts = 15.65 amps. In addition to that - diversity can be applied - which essentially implies that not all elements of the cooker/oven/hob will be turned-on at the same time.
@@alan2804 I cook and I do electrics although I cook indian cuisine....your comment is filled with ignorance trying to be Clever and sarcastic probably eat beans and toast all day
great video, can I connect the hood off the same cooker connection unit as the cooker and the oven? and what cable would I run? again 6mm or 2,5mm t&e?
Look at the manufacturers instructions. If the rating plate is under 3kw. Then 2.5mm HO7 rated cable should be sufficiont. In most cases you can buy 2 meters.
6mm cable not required for cooker and hob circuits on 32A MCB/RCBO (up to 15kW and after diversity calculations applied) as this is relevant to the old rewirable BS3036 fuse that applied a derating factor of 0.725 to a 30A fuse for the correct disconnection time if fault current. The next size of cable up from 4mm is 6mm(2) so most 'cooker' circuits were 6mm cable. A max 2.3kW oven can connect to a socket outlet with a plug top..
What is electrical diversity? is it some kind of average power consumption that you were calculating? The 6mm wire is not enough for this circuit but your MCB will protect it. The wiring you have done is not enough for a busy household, the MCB will keep tripping.
I think you will find 4mm is the wire you are looking for. 6mm is old requirement from old fuse boards with wire fuses, the 4mm cable is not comparable with them so had to use 6mm. That unfortunately carried over into new fuse boards. Check the on-site if you don’t believe me!!! Fact!
@@AndrewSmith-bb8sh Most kitchens have power hunger appliances like washing machines and fridges, it would be better to isolate the cooker and put the sockets on another fuse.
@@RandomStuff-ko5he Oh yes totally agree. I would never put my cooking appliances on my ring for kitchen appliances. Cookers and hobs must be separate, but only need a 4mm cable in 99% of the times. 😁
@@AndrewSmith-bb8sh I have a 4.2KW double oven and a basic ceramic hob connected by CCU as in the above diagram with 6mm wiring. If I change the hob for a 7KW induction hob, will I have to give it a separate 6mm supply.
Can I connect cooker to regular plug... Taking care not to operate all heaters/functions in sae time?? My over came with free cables. 6mm. And the regular plug is 4 mm...and it is oven with top heat plates in one appliance not separated
Wow you’re probably a mathematician 😂 why can’t you accept the fact the he just simply made a mistake and not just jump on the guy showing you can count to 5. Lol
@mariuskiudulas4498 there's nothing wrong in correcting someone so that they can edit and correct themselves? He wasn't rude in the way he pointed it out.
Question, I believe I can run a 32a induction hob and a 16a cooker with a 5a isolator with plug on my 6mm 32amp circuit? However, my cable is 6mm from the main board to the cooker and wondering if u can update to 40a mcb? The wire is in conduit within wall and concrete floor.
How would you get the 'wires' from the isolation switch above the lovely tiled splashback to the appliances? Not a pretty sight when cooking your turkey and all the trimmings...
How about a stove that can't be removed from the oven. According to the manufacturer, the sum of the simultaneous loads of the four burners + the oven, is 8600 WATTS (total load), this gives a consumption of 39A. Providing that the section of the main cable must be properly sized according to the absorved electrical power, in that case, the stove would have to be powered by a circuit whose conductor size is 10mm but the main power line, the one that takes electrical energy from the meter (counter) to the outlets, is 4mm size. The question is: when dimensioning the cables for the stove and their corresponding breakers, is the total load of the kitchen I should consider, or an estimated consumption, for example, two burners + the oven? I'll appreciate your help!!
Sebastian Benitez Seriously, if your supply tails are 4mm. I’d get that looked at. In the UK mains supply cable form service head to meter to consumer unit should now be 25mm2. BS7671 2018 AMD3 apply.
@@markgilder9990 I agree with Mark. It is also acceptable and perfectly OK to have 16mm2 tails for main fuses of between 60 - 80 Amps and 25mm2 for 100 Amp Main fuses as Mark mentioned above. 4mm2 is too small and does need looking at. It does depend on the Maximum demand however and varies from installation to Installation.
Great video 📹 👍 👏 ... could you show a video of where you use a 4mm to do the kitchen wiring I've seen this be done but want to know which method id better 2.5mm ring or 4mm which method should be used ?
4mm radial circuits are what are usually preferred now as ring circuits can have a 'cut' in the middle somewhere, and then you risk overloading the wires if all you load happens to be on the side of that cut. It also makes spuring off in the future easier.
I’m putting in a new kitchen I have 6mm 32amp with wall switch I want to change the Current socket as it’s for a gas cooker so only ignition at moment to a dual cooker outlet then 4mm to 2 single sockets which feed 13amp cooker 13amp hob doesn’t that sound acceptable
2x sockets at 13amp each = 26amp. That leaves 9amps free before the circuit breaker kicks in. 9 amp = ~2100watts. You will have a very comfortable margin of safety.
Woah woah woah, you lost me at "nobody uses the oven and all four rings of the hob at the same time". Somebody has never cooked Christmas dinner for 12 before..
This was going great until you said “.... nobody at home uses 4-rings of the hob at the same time and, also, the oven at the same time as the hob.” I do, and I know other people that do as well. There are no other ‘regular’ home appliances that will use as much electrical energy as an electrical hob and oven in the same time besides an electric hot water element. A better wiring assumption would be to consider a worst case scenario rather than a best case scenario, and simply running two separate connections to the main circuit breaker would solve this, and it would avoid future possible problems. 1- the connection to the MCB for the hob would require a 40-amp breaker / fuse (due to device inefficiencies and wire age) - a safety factor of 25%. 2- the connection for the oven would require a 20-amp breaker / fuse (due to device inefficiencies and wire age) - a safety factor of 25%. In each case the breaker switch fuse is slightly oversized by a few amps to allow for aging of the wiring and inefficiencies of the devices over time. Manufacturers, for instance, will not all use the same quality wiring inside these appliances. Most of these devices should operate for at least 10-years. Your wiring does not consider any increase in electrical resistance due to unforeseen circumstances.
You're not using all four rings for hours at a time are you though? It's not a constant load and you don't need to design the circuit as if it were. Also, increasing the breaker *reduces* the safety factor for a given cable size.
No proving the circuit is dead by testing with a GS38 two pole voltage indicator, did not test when finished to insure that it is safe to use, ie R1+R2 , insulation resistance and RCD tests also external loop impedance ie Ze . And didn’t fill out a minor works certificate. 👎👎👎👎
Straight to the point. No messing about. Nice one mate.
Very informative. Thanks for showing. But a slight correction to be made. 20.5a + 5a is 25.5a 😁.
Great video .. Would be nice to see the other connection been installed.. Big thank you
Your videos are exactly what I want. I have been looking for a better video about Electrical installation after years of doing electrical installation level 2 with no job.. I needed a refresh and none of the other video was more of practical than this..you doing good job..thanks so much for all this videos..
How you getting on you electrician now? Or did you do something rlse
Really love the way you make the videos very step by step practical including sizes of MCB's Cable etc
I love your videos!!! Such good and easy way to learn. Thank to you I’ve made so much progress on my build.
When you say, not everything is being used at once - a Christmas morning comes to my mind ;)
And every Sunday dinner at me Nans
Makes no difference, the hob rings power up and down as required it will never trip.
you can have upto 15kw of cookers hobs etc on a 32 amp mcb.
Your videos are very well explained. Very helpful - thanks.
Amazing and the graphical representation helps an great deal. Nice work 👍🏾
Excellently explained video thankyou so much
You're the man. Thumbs up. Subscribed
Good and clear instructions 👍
Advice please. I’ve got a 2.4kw oven which I put on a 13a spur as suggested but don’t like this I want to put it on the main cooker/hob switch. This circuit is on a 32a mcb and 10mm cable and currently powers the 7kw electric hob. My idea is to spur from the hob plate in 6mm to an unswitched 13a plate so they are both on the same switch.
I can’t find a problem other than if the fuse blows I have to pull the oven out the cupboard but just wanted to run it past someone. Spark said just put them together but it’s the 13a that bothers me on that idea. Thanks.
Stick with the 13A socket you already have for the oven. You cant drop a cable size without fitting protection between the two different sized cables.
It's a great video. The only issue I have is when you added 20.5A + 5A = 25.5A in your diversity calculation ...the answer is 25.5A. It still falls within the parameters. Just a heads up👍
Was going to comment about that lol, he got his amps and kW mixed up 😁
What size of cable would you use from dual cooker connector to the oven if its already has a 2.5 mm and plug top attached can you commect the 2.5 into the dual cooker connector or does it need replacing with 6mm cable
I am working up a belling hob it has come with a 4 core wire. But the wire going to the old hob is 3 core wire. Do I connect L1 and L2 in to a 3 way wago connector. Interested to know
hi did u find out how to connect 4 wires to 3 core wire? if yes could u tell me please i need to wire mine cheers
Can you use a 10mm from the CU and wire an additional 2 gang socket?
Nice one bro really helped me out this video top man
Hi there! Putting new kitchen in now! Has 3 new appliances arrived: Induction hob 6.9kw; Single oven 3 kw and 3.3kw build in Microwave-oven. All seems to be a hard wiring, no plugs! I have 32aMCB and 6mm cable attached with Dual connector unit on the bottom! Has a busy household, so it is possibility what can use all on the same time. i think to switching Microwave oven to my downstairs sockets other 32a MCB through fused switch like you show on video and other two appliances to Cooker Dual connection unit!
Under Diversity calculation seems to be enough, but just want to make sure! Please help me to work out if you can!?
Your respond will be really appreciated!
Thanks in advance!!!
What did you do in the end?
Great informative video, I really like your channel. Many thanks
Thanks for making your videos nice and simple to understand . cheers Raj
Ur videos the videos that we all really want u r talented ✊✊✊
45 amp cooker switch?
Hi I know this video was posted long time ago, I have a question do you need a RCD in your consumer unit or fuse box?, and also if you put 45A in your cooker switch, when will be disconnected in case of overload if you installed your ciurcuit breaker of 32A ?
What a great informative video. 👍🏾👍🏾👍🏾
What about double ovens is the wiering the same as single ovens.
in that given diagram, where can I possibly add the cooker hood connection without a plug, or I'll just connect a plug top and into the one of the sockets on the wall? thanks!
In my kitchen I ran a spur from the worktop double socket (on a ring circuit) up behind the wall units to a double socket on top for my cooker hood.
I did however have drywall on studs so easier to fish a wire up from behind the socket with no tile damage etc
My hob and oven both didn’t come with wires so was wondering what amp wires should I buy to connect both of these?
Check part p. Socket should be 10cm from the hob. 30 cm from a sink
Read this - 300 mm is the recommendation but it's not a regulation, either for the cooker switch or for the socket near the sink. They suggest a min distance of just 100mm. As there's no requirement for a cooker switch, there's no minimum or maximum distance.12 Sep 2015
I would not want my socket 100mm from a hob of any type. 300mm sounds good
H4. The control switch or cooker control unit should be placed within 2m of the appliance, but not directly above it. Page 190 of the On Site Guide.
Very informative Videos. Thank you.
For induction how 7.2 KW and cable length 20-25m is 6mm cable will be enough?
Excellent!
Yes but thatshowed one appliance being connected, how do you connect two to a dual 45a switch?
Can I use 20A breaker for IKEA oven?
Could I use 20A breaker for IKEA oven?
That would be determined by how many watts your Ikea oven is rated at. for example if your oven is rated at 3600w (aka 3.6Kw) and the nominal power supply to your house is 230v - then to find out what size cable and breaker you would need you have to calc. the required amps. To do this, you use the formula (Amps = Watts divided by Volts). So for in the example - the Oven is 3600 Watts divided by the supply voltage which is 230 Volts = 15.65 amps. In addition to that - diversity can be applied - which essentially implies that not all elements of the cooker/oven/hob will be turned-on at the same time.
Hi - can you spur off the cooker connector and add a socket
I don't understand the last part where you wire the dual connector? Would there be three lots of wires how does it connect to single plug ?
Dual ccu has an inlet and two outlets
@@Михаиллеви
......... and doesn't connect to a 13amp plug.
Great video although for kitchen I didn't think u would calculate diversity for kitchen as its highly likely that everything is used at once...
You dont do the cooking obviously
@@alan2804 I cook and I do electrics although I cook indian cuisine....your comment is filled with ignorance trying to be Clever and sarcastic probably eat beans and toast all day
Havnt you got a video on how to fit the over/cooker
great video, can I connect the hood off the same cooker connection unit as the cooker and the oven? and what cable would I run? again 6mm or 2,5mm t&e?
As you said we need 54amp breaker for oven and cooker which is10800 watts isn’t that high power to use the same breaker for only cooker or only oven ?
45amp load is max total. Divrsity more than halfs that load so 32amp mcb and 45amp rated isolatoor correct
Great channel mate and appreciate all the videos you put up 👍
Can I use 10mm instead 6mm for hob and oven ? Thank you
Yes
Thx u relly good 👍
What size cable to the oven for the dual outlet plate?
Look at the manufacturers instructions. If the rating plate is under 3kw. Then 2.5mm HO7 rated cable should be sufficiont. In most cases you can buy 2 meters.
Great graphics for the initial demonstration
Isn’t 20.5A +5A =25.5A
It surprised me how far I had to scroll down the comments to find someone else that noticed the mistake...
How do I add a single socket from an existing double to plug in an extractor fan?
amazing video.u are the super man
I like to make the CPC the longest to ensure that it remains intact after the phase and neutral should the flex be pulled from the outlet.
6mm cable not required for cooker and hob circuits on 32A MCB/RCBO (up to 15kW and after diversity calculations applied) as this is relevant to the old rewirable BS3036 fuse that applied a derating factor of 0.725 to a 30A fuse for the correct disconnection time if fault current.
The next size of cable up from 4mm is 6mm(2) so most 'cooker' circuits were 6mm cable. A max 2.3kW oven can connect to a socket outlet with a plug top..
What is electrical diversity? is it some kind of average power consumption that you were calculating? The 6mm wire is not enough for this circuit but your MCB will protect it. The wiring you have done is not enough for a busy household, the MCB will keep tripping.
6mm is completely fine for this circuit.
I think you will find 4mm is the wire you are looking for. 6mm is old requirement from old fuse boards with wire fuses, the 4mm cable is not comparable with them so had to use 6mm. That unfortunately carried over into new fuse boards. Check the on-site if you don’t believe me!!! Fact!
@@AndrewSmith-bb8sh Most kitchens have power hunger appliances like washing machines and fridges, it would be better to isolate the cooker and put the sockets on another fuse.
@@RandomStuff-ko5he Oh yes totally agree. I would never put my cooking appliances on my ring for kitchen appliances. Cookers and hobs must be separate, but only need a 4mm cable in 99% of the times. 😁
@@AndrewSmith-bb8sh I have a 4.2KW double oven and a basic ceramic hob connected by CCU as in the above diagram with 6mm wiring.
If I change the hob for a 7KW induction hob, will I have to give it a separate 6mm supply.
I'd have loved an explanation of why the calculations are required..?
Really useful ..
Great video. Can I connect kitchen fan extractor to cooker connector? Is it a good solution? I have electric oven and gas hob.
Very informative video 👍
Fantastic job very helpful this video 👌
How do you wire the hob though?
Into the ccu
Love your help thank you
Hello u saying is any socket is 30cm from cooker or hob but in green book of building regulation is saying 10cm from cooker or hob
Yes that's right it's the minimum now
Diversity 20.5A+ 5A = 25.5A not 21A as you stated
Can I connect cooker to regular plug... Taking care not to operate all heaters/functions in sae time?? My over came with free cables. 6mm. And the regular plug is 4 mm...and it is oven with top heat plates in one appliance not separated
😂
Wow you’re probably a mathematician 😂 why can’t you accept the fact the he just simply made a mistake and not just jump on the guy showing you can count to 5. Lol
@mariuskiudulas4498 there's nothing wrong in correcting someone so that they can edit and correct themselves? He wasn't rude in the way he pointed it out.
Question, I believe I can run a 32a induction hob and a 16a cooker with a 5a isolator with plug on my 6mm 32amp circuit?
However, my cable is 6mm from the main board to the cooker and wondering if u can update to 40a mcb? The wire is in conduit within wall and concrete floor.
Sorry
What was the procedure to calculate the diversity??? Plz
on site guide Appendix A, Table A1 BS7671
Hi, must I use a connection unit.. can’t the wires go directly into the 45a dp socket ?? Thank you
How would you get the 'wires' from the isolation switch above the lovely tiled splashback to the appliances? Not a pretty sight when cooking your turkey and all the trimmings...
How about a stove that can't be removed from the oven. According to the manufacturer, the sum of the simultaneous loads of the four burners + the oven, is 8600 WATTS (total load), this gives a consumption of 39A.
Providing that the section of the main cable must be properly sized according to the absorved electrical power, in that case, the stove would have to be powered by a circuit whose conductor size is 10mm but the main power line, the one that takes electrical energy from the meter (counter) to the outlets, is 4mm size.
The question is: when dimensioning the cables for the stove and their corresponding breakers, is the total load of the kitchen I should consider, or an estimated consumption, for example, two burners + the oven?
I'll appreciate your help!!
Sebastian Benitez Seriously, if your supply tails are 4mm. I’d get that looked at. In the UK mains supply cable form service head to meter to consumer unit should now be 25mm2. BS7671 2018 AMD3 apply.
@@markgilder9990 I agree with Mark. It is also acceptable and perfectly OK to have 16mm2 tails for main fuses of between 60 - 80 Amps and 25mm2 for 100 Amp Main fuses as Mark mentioned above. 4mm2 is too small and does need looking at. It does depend on the Maximum demand however and varies from installation to Installation.
The 7.2kW fits into a 32A fuse at 230 to 240V, 6mm² cable
A 16A fuse is suitable for the oven with 3.6kW, 2.5 mm² cable
What happens if I connect 6mm cable to cooker connector unit first then connect 6mm cable to DP cooker switch
Great video 📹 👍 👏 ... could you show a video of where you use a 4mm to do the kitchen wiring I've seen this be done but want to know which method id better 2.5mm ring or 4mm which method should be used ?
4mm radial circuits are what are usually preferred now as ring circuits can have a 'cut' in the middle somewhere, and then you risk overloading the wires if all you load happens to be on the side of that cut. It also makes spuring off in the future easier.
If you simply plugged the oven into the ring circuit what is the diversity ?
3.6kw. You can't. Too juicy. Recommended 2kw and above on own circuit
I always make sure minimum Iz>I1, it is better Iz>I2
John wards cooker diversity is correct you need to refresh your calculations by the on site guide .
I’m putting in a new kitchen I have 6mm 32amp with wall switch I want to change the Current socket as it’s for a gas cooker so only ignition at moment to a dual cooker outlet then 4mm to 2 single sockets which feed 13amp cooker 13amp hob doesn’t that sound acceptable
2x sockets at 13amp each = 26amp. That leaves 9amps free before the circuit breaker kicks in. 9 amp = ~2100watts. You will have a very comfortable margin of safety.
How to connect a 3 phase cooker to a singel phase power supply. The cooker is rated at 4400 watts.
Woah woah woah, you lost me at "nobody uses the oven and all four rings of the hob at the same time". Somebody has never cooked Christmas dinner for 12 before..
The regulations regarding distance from hob is now 100mm either side
If the cooker come with the cable but no plug and the cable is 1.5mm2
I think a 10mm cable you be safer than a 6mm cable
Would be safer
You can apply diversity to a cooker circuit. Check out John Ward’s maximum demand and diversity.
6mm is max rated to 47amp and here we have 21 amp load
Are you running a shower cooker?
You final calculation should be 25.5A xxx
This was going great until you said “.... nobody at home uses 4-rings of the hob at the same time and, also, the oven at the same time as the hob.”
I do, and I know other people that do as well.
There are no other ‘regular’ home appliances that will use as much electrical energy as an electrical hob and oven in the same time besides an electric hot water element.
A better wiring assumption would be to consider a worst case scenario rather than a best case scenario, and simply running two separate connections to the main circuit breaker would solve this, and it would avoid future possible problems.
1- the connection to the MCB for the hob would require a 40-amp breaker / fuse (due to device inefficiencies and wire age) - a safety factor of 25%.
2- the connection for the oven would require a 20-amp breaker / fuse (due to device inefficiencies and wire age) - a safety factor of 25%.
In each case the breaker switch fuse is slightly oversized by a few amps to allow for aging of the wiring and inefficiencies of the devices over time. Manufacturers, for instance, will not all use the same quality wiring inside these appliances.
Most of these devices should operate for at least 10-years.
Your wiring does not consider any increase in electrical resistance due to unforeseen circumstances.
You're not using all four rings for hours at a time are you though? It's not a constant load and you don't need to design the circuit as if it were. Also, increasing the breaker *reduces* the safety factor for a given cable size.
25.5A+5A=25.5A
Wiring 2.5mm built in oven flex into a 6mm 32amp circuit does not sound like a great idea.
He mentioned that's being spurred off the ring via fcu so should be fine if the oven less than 2kw
A 3.6kw oven would probably come with 2.5mm flex wired in. Without diversity its still only 15amps. Fine off ccu fed by 6mm.
Then you will have a 2 5mm flex protected by a 32amp breaker. Not fine.
Only if wired directly. The flex may have a plug top with a 13a fuse and this can safely connected to a 32A circuit if the oven is max 2.3kW (limit)
You need a separate ring circuit for the oven,which is not explained in this video.
WERE IS THE AUDIO can NOT HEAR YOU
10mm cable is needed here
Why ?
No proving the circuit is dead by testing with a GS38 two pole voltage indicator, did not test when finished to insure that it is safe to use, ie R1+R2 , insulation resistance and RCD tests also external loop impedance ie Ze . And didn’t fill out a minor works certificate. 👎👎👎👎
take the food out of your mouth xd
You only need 4 mm cable for 32 Amp MCB. Plus calculations P/V -230 V not 240.
Actual voltage UK is 240