50 amp kitchen range cooker

[BuildingNovice]

I am buying a range cooker rated 43 amps (although manufacturer recommeds a 50 amp connection).

As we have 100amps total coming into the house, is this likely to cause major problems?

Is there a way I can estimate total amps currently being used in the house by looking at the electric meter?

Any help much appreciated.

 

[mikhailfaradayski]

I am buying a range cooker rated 43 amps (although manufacturer recommeds a 50 amp connection).

As we have 100amps total coming into the house, is this likely to cause major problems?

not if installed correctly

Is there a way I can estimate total amps currently being used in the house by looking at the electric meter?

not really from looking at the meter. I suppose its possible, but id be surprised if any spark has done it that way (in a domestic) How long would you be prepared to look at the meter for?

Any help much appreciated.

What do you know about the design of the install overall? what do you know about diversity? Or, more importantly, what does your sparky know about it?

 

[JohnD]

have you got an electric shower or a heated swimming pool?

the 100A to a supply is usually much more than will ever be needed. The most my house ever uses would be about 50A if (which is very unlikely) I was running the heating elements on the washing machine, the drier, the oven, and the dishwasher all at the same time.

Even with your huge cooker (why don't you get one with a gas hob, by the way?) all the elements are on thermostats, so they come on full for a few minutes, then cycle on and off so that it is very difficult to make it take maximum load, unless you turn everything full on from cold at the same time.

There are some calculation rules called "diversity" but in principle, the idea is that you are never likely to have everything full on at the same time, so it is OK to have total appliances which exceed the maximum current available. However, if you have one or more electric showers, then you can expect a problem, because these do take full power continuously.

With that big cooker though, make sure your consumer unit, tails and circuit are all up to date and adequately sized. If you electrical installation is old, it is worth having it inspected.

 

[BuildingNovice]

mikhailfaradayski

Thanks for your post.

We have a 'single phase watt hour meter' which has a reading (currently 10851) which I assume is watts used since a certain point (not sure what).

I thought maybe if there were 2 measurements you could take say 15/30 mins apart, having put on 'normal' appliances, you might be able to work out the amps/watts used.

I googled diversity and can see the logic behind it. I am sure my electrician knows about this.

 

[BuildingNovice]

JohnD

Thanks for your response.

We have neither an electric shower or swimming pool - just normal things like american fridge freezer, flat screen tv, dishwasher etc (and maybe not so normal 4 or 5 computers).

The cooker we are getting has a gas hob (Wolf range), but has two electric ovens which must be quite powerful to demand that ampage.

We want to be covered in case we do have many appliance on at once (those mentioned above and lights etc), which is quite possible when having guests around.

Is the worst that can happen be the consumer unit tripping and needing resetting?

 

[ColJack]

that would be kilowatt hours since it was installed..

if you switched on a 3KW electric heater for an hour, it would go up by 3.. ( ok so it would probably only go up by 1.5-2.5 as it cycles on and off as well ).

 

[JohnD]

the worst that could happen, if your wiring is in poor condition and inadequate for the load, is that your house could burn down

otherwise, if you draw more current than the MCB for the cooker circuit is rated for, the cooker MCB will trip (fuses are not suitable)

Or, if you run the oven flat out, plus a huge number of other electric appliances at the same time, the main fuse will blow. However they need a considerable overcurrent for a considerable time to blow, and you would probably notice the house and kitchen getting unbearably hot, and hot smells from the wiring, before that happened.

 

[BuildingNovice]

Thanks JohnD

I'm sure (!) my electrician will check that the wiring is adequate for the load (I think he is fitting a new 16 or 20 mm wire for the oven).

 

[holmslaw]

..

 

[Steve]

The DNO size their substations based on 2KW per house.

This is the average draw of an average house according to them.

As for a cooking appliance rated at 43 amps, I'd stick it on 6mm² cable and a 32A MCB. Both ovens will have thermostats, therefore even when on, they wont be pulling power all the time.

Godknows why the manufacturer wants a 50A MCB. Just trying to make their products seem more macho I expect.

 

[JohnD]

my house uses an average of 0.8kWh/hour, over the year.

 

[chippy5]

the only time the range will get close to 43amps is if you turn every oven and ring on at the same time to blow the 100amp fuse you'd need everything in your house running at maximum range, power shower, all lights etc. i install Rangemaster induction hob range cookers regularly u'd need a 50 amp trip on the board and a 10mm cable

 

[BuildingNovice]

I understand 1 Watt is 1 joule of energy per second, so it is a rate of power use and not a quantity of energy.

So if my computer is 375 watts, then I assume that means it uses 375 joules per second?

1 KW hour is 1000 watts per second used over an hour, so that is 1000 x 60 x 60 joules in quantity (= 3.6 megajoules).

So if my supply is 100 amps, then at 240V that is 24,000 watts or 24 KW
per second?

Am I right?

 

[JohnD]

So if my supply is 100 amps, then at 240V that is 24,000 watts or 24 KW
per second?

Am I right?

No
It is just 24kW

Which, if you run it for an hour at that rate, is 24kWh.
If you run it for two hours it is 48kWh
If you run it for 1 second it is only 0.06666666kWh



24kW is enough energy to keep a large house warm in winter. My medium house used 103kWh per day during January (so the boiler was running at an average of 4kW)

thus you will feel very hot if you run enough appliances to use that much.

about 8 fan heaters worth at 3kW each.

edited because I explained it wrong

 

[mikhailfaradayski]

mikhailfaradayski

Thanks for your post.

We have a 'single phase watt hour meter' which has a reading (currently 10851) which I assume is watts used since a certain point (not sure what).

I thought maybe if there were 2 measurements you could take say 15/30 mins apart, having put on 'normal' appliances, you might be able to work out the amps/watts used.

i suppose you could, i would think it would be clumsy and in-accurate unless you were prepared to take lots and lots of readings ( a few hundred?) including through the night.

I googled diversity and can see the logic behind it. I am sure my electrician knows about this.

Might sound like a cop-out, but i would leave it to him.
Is this the same build that you mentioned last week, about the spotlights?
If so, then the spark would make an assesment of the overall expected loads and with a little bit of magic would define max demand from that.

As you have taken the time to find out about diversity, im sure you'll appreciate that there are differing levels of diversity factors depending on what the circuits are supplying ( e.g. a light circuit and a electric shower have different factors applied)and the nature of the installation (e.g. domestic and commercial have different factors aswell)