Thicko moment, we have bought a little van in France but it has no grill/oven. I am looking at an 800watt grill & oven to purchase, but the site has only 8amp... I have an old chart which says its okay as it will draw 3 amp. Just wanted some re-assurance from all you knowledgeably people, as you helped time & time again.
Wattage and Amps
- Thread starter denise_374355927
- Start date
Hi Denise. You should be ok with that appliance.
If you look at the maximum wattage of an appliance then divide that by the local voltage then the result is the Amps the appliance will use.
I am not familiar with continental voltages so be aware that with a uk voltage of 240 volts the appliance will use considerably less current (Amps) than a local supply of only 120 volts.
3.3 amps. for 240 volt. 6.6 amps. For 120 volts
Hope this helps .
regards Brian
If you look at the maximum wattage of an appliance then divide that by the local voltage then the result is the Amps the appliance will use.
I am not familiar with continental voltages so be aware that with a uk voltage of 240 volts the appliance will use considerably less current (Amps) than a local supply of only 120 volts.
3.3 amps. for 240 volt. 6.6 amps. For 120 volts
Hope this helps .
regards Brian
Europe is standard now on nominally 230Volt.
Realy odd on this site now, sometimes it does not post (compatability issues) this time it double posted?
Realy odd on this site now, sometimes it does not post (compatability issues) this time it double posted?
ChrisUK said:
Hi Chris
When you have clicked save ( only do it once )
Then click on the forums tab.
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If your compatability icon is blue there should not be a problem posting .....
Correction, when the voltage is less or more than the appliance is rated at, the amperage does not go up or down, it is the wattage output that varies.
IE, if the grill is rated at the EU 'mean' of 230volts and 800W, that is 800/230 giving 3.48 amps, but the resistance of the appliance has not changed, (230/3,48 = 66ohms and constant), so the amps won't change, . This means 240 x 3.48 gives an improved 835W @ the UK's more common 240v and 766W @220v where this lower voltage is present which is quite often on very busy campsites!
IE, if the grill is rated at the EU 'mean' of 230volts and 800W, that is 800/230 giving 3.48 amps, but the resistance of the appliance has not changed, (230/3,48 = 66ohms and constant), so the amps won't change, . This means 240 x 3.48 gives an improved 835W @ the UK's more common 240v and 766W @220v where this lower voltage is present which is quite often on very busy campsites!
Yes Gary you are spot on with that. I was not thinking correctly with my reply. For some reason I have got French power supplies in my head as 120 volts. Although never having been there I don't know how I have presumed that. I presumed an 800 watt heater bought for that voltage would have used more amps than one bought to suit 240 volts.
sorry if I have confused your thinking Denise
cheers for now Brian
sorry if I have confused your thinking Denise
cheers for now Brian
I'm sorry if this seems pedantic, but the above statements are not quite right. The Wattage of an appliance does not remain static if the supply voltage changes. It follows any change in supply voltage
For resistive heating devices (such as grills and ovens etc.), then there are two basic electrical equations that apply:
V=IR and W=VI (also W=IxIxR)
where V is the supply voltage, I is the current in Amps and R is the resistive value of the load, and finally W is the Wattage of the device. These simple equations can of course be rearranged to find any third term from two known ones, so for example and of more use in this situation:-
W/V I and V/A=R (and W/R=I2)
Lets put the values into the equations (figures rounded to three significant figures):-
800W / 230V = 3.48A and 230V / 3.48A = 66.1R
Now for any given appliance what doesn't change is the element, and the important characteristic is its hot resistance which we have calculated to be 66.1 (in reality the hot resistance will also change but by only a relatively small amount so we can for these purposes ignore it.)
Now recalculate for 240V
240v / 66.1R = 3.63A And that means the appliance will convert
240V x 3.63A = 871W
Although the EU wide (including the UK) theoretically now operates at a nominal 230V ac, the tolerances on the supply can still allow 240V to arise in some places. All values quoted on EU CE approved appliances will be for a nominal 230V supply, but will be designed to safely cope with the supply tolerances.
For resistive heating devices (such as grills and ovens etc.), then there are two basic electrical equations that apply:
V=IR and W=VI (also W=IxIxR)
where V is the supply voltage, I is the current in Amps and R is the resistive value of the load, and finally W is the Wattage of the device. These simple equations can of course be rearranged to find any third term from two known ones, so for example and of more use in this situation:-
W/V I and V/A=R (and W/R=I2)
Lets put the values into the equations (figures rounded to three significant figures):-
800W / 230V = 3.48A and 230V / 3.48A = 66.1R
Now for any given appliance what doesn't change is the element, and the important characteristic is its hot resistance which we have calculated to be 66.1 (in reality the hot resistance will also change but by only a relatively small amount so we can for these purposes ignore it.)
Now recalculate for 240V
240v / 66.1R = 3.63A And that means the appliance will convert
240V x 3.63A = 871W
Although the EU wide (including the UK) theoretically now operates at a nominal 230V ac, the tolerances on the supply can still allow 240V to arise in some places. All values quoted on EU CE approved appliances will be for a nominal 230V supply, but will be designed to safely cope with the supply tolerances.
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