ceramic hob

[vanvliet]

Would using this trip the caravan site electrics ?
http://www.johnlewis.com/tefal-ih201840 ... 92363#next

[wonkanoby]

•9 power levels: from 450W to 2100W

the last looks way to much to me

[g8dhe]

2100/240=8.75 Amps, which is half of the maximum possible on a full 16 Amp feed, however plenty of sites will not be able to do a full supply many are only 10Amps so you would be pushing it a bit!! You would also need to make sure the internal wiring in the Bongo is up to the job as well!

[elbee]

The correct way to work out the current draw of any appliance is to take the maximum wattage ie 2100w (2.1Kw) and divide this by 230v this works out at just over 9 amps. As stated earlier most campsites have a 10amp supply (MCB) so your ok as long as you don't have any other appliances operating (drawing current) at the same time.

HOWEVER ceramic hobs rarely draw that amount of current. In fact when I calculate maximum current in my job as a domestic electrician using BS7671 as a guide I apply a 66% diversity allowance to cookers and hobs. So in laymans terms your hob will rarely reach the 2.1Kw max.

As an example... Most domestic kitchen kettles operate at around 2.2Kw and have no diversity at all because they are a "water heater" and they won't normally trip a 10amp supply if no other appliances are drawing current.

I guess the ultimate question is what other items are you likely to be using from the hook up at the exact same time as using the hob as this will determine whether you trip the breaker (MCB)

As for your van electrics I'm not sure what system you have fitted but I assume you have a little consumer unit as fitted by most converters comprising if a 16 amp and maybe an additional 6 amp breaker for lighting. Let me know either way and I can advise

[helen&tony]

Hi
The way I understand the hook-ups, is that Geoff is right...10 amps IF YOU'RE LUCKY!!!!
Having lived for 3 months on a site when we sold the house prior to emigrating, I confirmed suspicions that when other folk are on site, if more than one or two folks put the kettle on, the whole lot goes down ...Quite a few people working away from home regularly use caravans "stored" away from home as a weekday base, and we had several regulars on the 5-van site we stayed on Oh, and the hookups were pretty well installed!
Cheers
Helen

[elbee]

I can't comment on individual campsites but the hookups I've installed at campsites have a weatherproof mini garage type consumer unit at each pitch with a either a 10 or 16a MCB ( depending on number of pitches and max available current at the site) so if an individual pitch exceeds the 10a only that MCB should trip.

If a few people put the kettle on at the same time and the whole system goes there's something seriously wrong with the design of the system.

As I stated earlier a kettle uses its full power pretty much all the time until it turns off but a ceramic hob has a thermostat so it would be unlikely that it would reach its maximum stated wattage during normal operation.

[elbee]

There is also this model which has slightly less power

http://www.amazon.co.uk/Andrew-James-Di ... HT60TZ9H98

Apparently used on Masterchef?

[mikeonb4c]

As I stated earlier a kettle uses its full power pretty much all the time until it turns off but a ceramic hob has a thermostat so it would be unlikely that it would reach its maximum stated wattage during normal operation.

But, rather like with the bhp rating of a car engine, isn't the wattage of a device the measure of what it will use when switched in/on (i.e. before the thermostat notifies that the required temp has been reached and switches the device off). So whilst it may not draw high current for long, it will still draw a high current when switched in. And does something have to be added to allow for initial switch-on load when, for example, resistance in the coldheating element is lower that it would be when at working temperature. And if trips work on detecting peak currents, this could be a material consideration.

I'm not an expert on any of this, so these are just things I'm trying to understand.

[helen&tony]

Hi Elbee
You're almost certainly right on the installations....they are often installed by "experts"...the drip under pressure type ...As a rule I don't use hookups, and prefer to use small sites with bare necessities, but the one we lived on was a farm, and probably installed by the farmer....they were proper little hook-up stations though!
Cheers
Helen

[elbee]

As I stated earlier a kettle uses its full power pretty much all the time until it turns off but a ceramic hob has a thermostat so it would be unlikely that it would reach its maximum stated wattage during normal operation.

But, rather like with the bhp rating of a car engine, isn't the wattage of a device the measure of what it will use when switched in/on (i.e. before the thermostat notifies that the required temp has been reached and switches the device off). So whilst it may not draw high current for long, it will still draw a high current when switched in. And does something have to be added to allow for initial switch-on load when, for example, resistance in the coldheating element is lower that it would be when at working temperature. And if trips work on detecting peak currents, this could be a material consideration.

I'm not an expert on any of this, so these are just things I'm trying to understand.

I'm not aware of any start up current in a cooker or hob as you may get in an old florecent light or a motor for example .

When you design a circuit for a cooker or electric hob you apply divercity to the calculations. Not 66% as I stated earlier in the post typo that's for lighting. But let's say your cooker is rated at 14Kw (14000w) then you divided it by 230v =61A !! ....however when you apply divercity you take the first 10A and then 30% of the remainder and add together so that's 15.3A +10A =25.3A that's the max it should draw in normal use. So you would fit a 6mm cable and protect it with a 32A MCB

Of Course the same formula cannot be applied to that little hob as it's less than 10a but diversity still applies.

[mikeonb4c]

As I stated earlier a kettle uses its full power pretty much all the time until it turns off but a ceramic hob has a thermostat so it would be unlikely that it would reach its maximum stated wattage during normal operation.

But, rather like with the bhp rating of a car engine, isn't the wattage of a device the measure of what it will use when switched in/on (i.e. before the thermostat notifies that the required temp has been reached and switches the device off). So whilst it may not draw high current for long, it will still draw a high current when switched in. And does something have to be added to allow for initial switch-on load when, for example, resistance in the coldheating element is lower that it would be when at working temperature. And if trips work on detecting peak currents, this could be a material consideration.

I'm not an expert on any of this, so these are just things I'm trying to understand.

I'm not aware of any start up current in a cooker or hob as you may get in an old florecent light or a motor for example .

When you design a circuit for a cooker or electric hob you apply divercity to the calculations. Not 66% as I stated earlier in the post typo that's for lighting. But let's say your cooker is rated at 14Kw (14000w) then you divided it by 230v =61A !! ....however when you apply divercity you take the first 10A and then 30% of the remainder and add together so that's 15.3A +10A =25.3A that's the max it should draw in normal use. So you would fit a 6mm cable and protect it with a 32A MCB

Thanks for explaining it elbee - sounds like nothing to worry about then!

[vanvliet]

Great stuff! I was thinking about a little hob to supplement my Bio cooker when on a site and paying for electricity anyway. I have no idea about electrics so learned a lot . Particular thanks to Elbee as he looked over the specs of my RCD and thinks that it is OK for this application . Just need to keep an eye out for a lower price than John Lewis are asking - - -