Mike B. Posted October 28, 2012 Share Posted October 28, 2012 Can anyone give me a difinitive answer on Electricity usage? People have kindly replied on this topic on other posts but I can't work out the ratios etc! If I plug in a 400watt or an 800watt halogen heater whilst on EHO on a site how many Kilowats would I use in 1 hour say or one day? I would also be running battery charger for leisure battery and fridge on mains. Any help appreciated Mike Link to comment Share on other sites More sharing options...
Tracker Posted October 28, 2012 Share Posted October 28, 2012 It's quite simple once you know how and as long as you know two of the three variables and have a calculator. Watts = amps times volts Amps = watts divide by volts Volts = watts divided by amps Watts is how much it consumes at any given point and Kilowatt hour is how much it uses in an hour. So, you know the watts is 400 and you know the mains volts is 230 (+/- 6% but we will ignore that for the purpose!) Therefore 400 watts at 230 volts = 1.74 amps and 800 watts is either twice 400 or 800 divided by 230 = 3.48 amps. Amps is a measure of current flow at any given time whereas watts is the measure of power consumption over a given time. Therefore 400 watts for one hour is .4 kw and 400 watts for 24 hours is 24 x .4 = 9.6 kw. The fridge will have a label on it or a handbook telling you the wattage on both 12v and on mains. Don't know about the charger for sure but hazzard a guess that if it charges at about 6 amps at 12v (equals about 72 watts plus a bit more for internal inefficiencies) it may well consume less than half an amp at mains voltage. Hope that helps clarify the mystery for you? Link to comment Share on other sites More sharing options...
colin Posted October 28, 2012 Share Posted October 28, 2012 Do you want to know Kw, Amps, or Kwh? Your post seems to suggest Kwh, in which case 400w at one hour = 0.40 Kwh Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted October 28, 2012 Share Posted October 28, 2012 Trust Tracker to complicate matters! *-) easy really...A = (x + y)2 = x2 + 2xy + y2 for all real numbers x, y. with A being to size of your pitch.....Simples Link to comment Share on other sites More sharing options...
Tracker Posted October 28, 2012 Share Posted October 28, 2012 JudgeMental - 2012-10-28 4:36 PM Trust Tracker to complicate matters! *-) easy really...A = (x + y)2 = x2 + 2xy + y2 for all real numbers x, y. with A being to size of your pitch.....Simples My apologies for complicating it - but your formula only applies to a standard pitch - if you want a jumbo sized pitch just plant one Viagra at each corner, water well and wait overnight. Link to comment Share on other sites More sharing options...
Mike B. Posted October 28, 2012 Author Share Posted October 28, 2012 Tracker - 2012-10-28 4:47 PM JudgeMental - 2012-10-28 4:36 PM Trust Tracker to complicate matters! *-) easy really...A = (x + y)2 = x2 + 2xy + y2 for all real numbers x, y. with A being to size of your pitch.....Simples My apologies for complicating it - but your formula only applies to a standard pitch - if you want a jumbo sized pitch just plant one Viagra at each corner, water well and wait overnight. Right -think I've got all that but.............................................if the pitch has water connection (be it jumbo or standard) does the flow affect the current? And if I plant a viagra at each corner would I have hard or soft wood and how long would it take to grow? *-) :-D Link to comment Share on other sites More sharing options...
Mike B. Posted October 28, 2012 Author Share Posted October 28, 2012 Thanks for the replies What I wanted to know in a nutshell was if I bought a small halogen heater (the one I've found is 400watt or 800watt by switch) and put it on in the van at night in Spain would it use masses of power. Working on 400 watts =.4kw per hour, then I could run it in the evening for a couple of hours easily without going over the site limit or tripping the EHU out. The idea was to do this and save my gas for cooking etc which should then last the full trip. I have stored Trackers formula now so I won't ask the same questions in future anymore! :-D Once again-thanks for the help-very much appreciated Mike Link to comment Share on other sites More sharing options...
Tracker Posted October 28, 2012 Share Posted October 28, 2012 Nearly right except that water flow will not help your currants nor will it help your sultanas as they are no longer live having been neutralised when they were separated from the earth.. The wood would start off soft but would harden into hard wood with time. However if not given special treatment called TLC the hard wood would soon revert back to soft wood again - wouldn't it. But wooden tits are another story for another day. Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted October 28, 2012 Share Posted October 28, 2012 refillable LPG system really makes more sense then worrying about gas use. we have a small 1000/500 watt blow heater, I know these halogen heaters turn of if you knock them over but I dont like them... Link to comment Share on other sites More sharing options...
flicka Posted October 28, 2012 Share Posted October 28, 2012 I have to agree with Eddie, we have never been keen on Halogen Heaters for use in the Van. It's not just a question of the possibility of them being knocked over, but also if anything (i.e.clothing) falls on to them. We use a 700w Oil Filled Radiator. wide base so much less possibility of being knocked over, safe if anything falls on it & silent so can be left on overnite if required. Link to comment Share on other sites More sharing options...
Mel B Posted October 28, 2012 Share Posted October 28, 2012 ... if you do use the 'viagra' trick to get a bigger (and harder) pitch, make sure you knock any awning pegs in BEFORE planting the viagra, once it starts to work you won't get them in!!! :D :D :D Link to comment Share on other sites More sharing options...
Mel B Posted October 28, 2012 Share Posted October 28, 2012 flicka - 2012-10-28 9:29 PM I have to agree with Eddie, we have never been keen on Halogen Heaters for use in the Van. It's not just a question of the possibility of them being knocked over, but also if anything (i.e.clothing) falls on to them. We use a 700w Oil Filled Radiator. wide base so much less possibility of being knocked over, safe if anything falls on it & silent so can be left on overnite if required. Agree with you both, halogen heaters are not meant to be left on overnight as far as I'm aware, they're not safe - it is too easy for something to fall, or be blown onto them during the night. You need to have an oil-filled, oil-less, or convection heater really. Link to comment Share on other sites More sharing options...
T8LEY Posted October 28, 2012 Share Posted October 28, 2012 You've got the technical info for the load now but did you know halogen heaters heat the objects in the space, rather than the space itself eg it feels like your eyeballs are being boiled. Also, you may find a 400W heater, or even 800W, will struggle to raise the temperature sufficiently when the outside level drops near zero. For your van volume I would have thought at least a 1500W fan assisted heater would be needed to achieve good comfort levels in a reasonable length of time. Oil filled radiators are probably the safest type of heater but unless the heat output is adequate, over 1500W in your case, you would have to anticipate your heating cycle or sit shivering for a while. I'd recommend a 1500W fan heater, which you could comfortably operate from a 10A EHU, and if it had a lower setting, even better, for smaller power supplies as well. Link to comment Share on other sites More sharing options...
Mike B. Posted October 29, 2012 Author Share Posted October 29, 2012 Thanks all for the replies. Must admit I hadn't realised a few points raised here. Maybe I should be looking at a fan heater instead. I hadn't intended leaving the heater on, just to take the chill off but maybe this is not the safest option after all Thanks Mike Link to comment Share on other sites More sharing options...
lennyhb Posted October 29, 2012 Share Posted October 29, 2012 JudgeMental - 2012-10-28 4:36 PM Trust Tracker to complicate matters! *-) easy really...A = (x + y)2 = x2 + 2xy + y2 for all real numbers x, y. with A being to size of your pitch.....Simples No he hasn't he's made it simple he has not even mentioned the difference between apparent power and true power, using Rich's figurer's will only give you apparent power, to get a correct figure for an ac circuit you need to work out the true power taking the impedance of the load into account. :D :D :D :D For normal use apparent power is good enough. (lol) Link to comment Share on other sites More sharing options...
Tracker Posted October 29, 2012 Share Posted October 29, 2012 I didn't think it would be long before a clever Alexander came along to muddy the waters - but you forgot the national Grid's 6% allowance on 230 volts which will also reduce or increase wattage up or down by - err 6% - the higher the voltage the lower the wattage! Top Tip Soak your tent pegs in a Viagra solution overnight to stop them bending when you hammer them into the ground. Just mind they don't stretch when you pull 'em out later! Link to comment Share on other sites More sharing options...
Brambles Posted October 29, 2012 Share Posted October 29, 2012 " the higher the voltage the lower the wattage! " Now you really have confused me Tracker. Link to comment Share on other sites More sharing options...
RogerC Posted October 29, 2012 Share Posted October 29, 2012 Mike B. - 2012-10-29 9:07 AMThanks all for the replies. Must admit I hadn't realised a few points raised here.Maybe I should be looking at a fan heater instead. I hadn't intended leaving the heater on, just to take the chill off but maybe this is not the safest option after allThanksMike Mike, you might consider trying a fan heater to take off the immediate chill and warm the MH then use a non oil filled rad to keep the background warmth. You are safer with the non oil rad on all night. Used independently they work off ehu no problem. We bought a fan heater (table top sized one) off 'fleabay' for less than £10.00 http://www.ebay.co.uk/itm/2000W-PORTABLE-SILENT-ELECTRIC-FLOOR-FAN-HEATER-HOT-COOL-UPRIGHT-/310483778318?pt=UK_Home_Garden_Hearing_Cooling_Air&hash=item484a467b0e and a non oil rad from Argos....http://www.argos.co.uk/static/Product/partNumber/4152686.htm now costs £64.99....pricy but peace of mind by not using oil filled. Link to comment Share on other sites More sharing options...
Tracker Posted October 29, 2012 Share Posted October 29, 2012 Brambles - 2012-10-29 9:55 AM " the higher the voltage the lower the wattage! " Now you really have confused me Tracker. OOOOOPs - sorry - typographical error (aka senior moment) shoulda said the higher the voltage the lower the current! Link to comment Share on other sites More sharing options...
Brambles Posted October 29, 2012 Share Posted October 29, 2012 Tracker - 2012-10-29 10:15 AM Brambles - 2012-10-29 9:55 AM " the higher the voltage the lower the wattage! " Now you really have confused me Tracker. OOOOOPs - sorry - typographical error (aka senior moment) shoulda said the higher the voltage the lower the current! You are still having a senior moment, the watt rating of appliance has not changed ( e.g impedance stays the same), voltage rises due to tolerance and therefore both the amps and the power used rises. (Ignoring any swich mode power supplies where the inverse viagra affect applies) Link to comment Share on other sites More sharing options...
Tracker Posted October 29, 2012 Share Posted October 29, 2012 Brambles - 2012-10-29 10:36 AM Tracker - 2012-10-29 10:15 AM Brambles - 2012-10-29 9:55 AM " the higher the voltage the lower the wattage! " Now you really have confused me Tracker. OOOOOPs - sorry - typographical error (aka senior moment) shoulda said the higher the voltage the lower the current! You are still having a senior moment, the watt rating of appliance has not changed ( e.g impedance stays the same), voltage rises due to tolerance and therefore both the amps and the power used rises. Oh bugger - some days the brain just will not engage fully. Link to comment Share on other sites More sharing options...
Mike B. Posted October 29, 2012 Author Share Posted October 29, 2012 Guys-all I wanted to know was about a small heater for my van!!! At this rate of argument you'd think I was wiring up the Hadron Collider for a chilly night on the Costas!! :-D :-D I'm gonna look at this fan heater on Ebay-thanks for that Mike Link to comment Share on other sites More sharing options...
T8LEY Posted October 29, 2012 Share Posted October 29, 2012 Just a couple of clarifications on previous posts. UK supply voltage tolerances are +10% / -6% on 230V. See below: http://www.schneider-electric.co.uk/support/getPDF.do?id=FA144717&version=1.0&country=UK&lang=EN&locale=null The power rating of an appliance is fixed, generally speaking, unless it has level controls. The things that can vary are the voltage, with supply variations and cicuit impedance, for instance, and current due to voltage changes. Link to comment Share on other sites More sharing options...
Brambles Posted October 29, 2012 Share Posted October 29, 2012 I bought one of those ebay fan heaters and the thermostat lasted one day, got the heater replaced and the hysteresis on the thermostat was so large it was as useful as a chocolate fireguard so took it back and bought a good ceramic element fan heater instead. Link to comment Share on other sites More sharing options...
Guest peter Posted October 29, 2012 Share Posted October 29, 2012 If you use a halogen heater in your van at night you will not be able to get to sleep owing to the light they give out. Despite what someone has said , halogen heater do heat the space and not objects. I know this, as we have one that my wife uses to heat her office. It has a tip over switch on the bottom which cuts the power if it gets knocked over. The case is made of plastic and never even gets warm. You can put your hand in front of it and it will not burn you. Link to comment Share on other sites More sharing options...
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