# Calculating usage/cost of 240V when on EHU



## spartacus (Jul 10, 2008)

I was recently handed a written notice on a campsite to say that, as we were a motorhome, they had been monitoring our electricity usage and as a consequence the nightly fee was going to increase by £3 as, in the site owners words "we're paying you to stay here" 

Now made alternative arrangements on a farm which is proving an excellent winter base whilst fulltiming/working, free of the restrictions and compromises often encountered on sites. 

In order to arrive at a fair price for the facilities we are using I would like to calculate our electricity usage. The main culprit will be the Truma 6E heating/boiler which at this time of year is on 24/7, sometimes being run dual fuel (gas) as well to keep the temperature comfortable.

Looking at the Truma manual it states an average consumption, on 240V, of 1.3A, so using my rusty Ohms law I work this out at 184 watts, so lets say 0.2 kw/h. Looking at Scottish Power rates for domestic electricity @ 10p per kw/h (approx.) this equates to about 48p over a 24 hour period by my reckoning.

Do these sums look about right? On top of this is the use of kettle, hairdryer and battery charging to replace drain of 12V system.

What I'm trying to arrive at is a rough daily cost of 240V useage, would it be fair to say around a £1 a day in total???


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## artona (Jan 19, 2006)

click here ot see an owl electricity meter

Get yourself one. You simply clamp it to the cable and it tells you what you are using. At present we are using 40p per hour because I have put a fan meter on for a while

stew

edit - I use one at home on the mains. I have no reason to think it will not work on a hook up cable but I have not tried it


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## JockandRita (Jun 1, 2005)

spartacus said:


> I was recently handed a written notice on a campsite to say that, as we were a motorhome, they had been monitoring our electricity usage and as a consequence the nightly fee was going to increase by £3 as, in the site owners words "we're paying you to stay here"
> 
> Now made alternative arrangements on a farm which is proving an excellent winter base whilst fulltiming/working, free of the restrictions and compromises often encountered on sites.
> 
> ...


Hi there,

I can't confirm you figures, but hope that you aren't too far off.

When making alternative arrangements, I hope you told the camp site owner what they could do with their £3 a night hike in fees. :x :x :x

Regards,

Jock.


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## peedee (May 10, 2005)

Your figures are incorrect, better to do as Stewart says. Even if the arithmetic was correct it is difficult to work out exact consumption with appliances switching on and off but your Truma is 312watts at 240volts.

IMO. a typical household consumption would be between £2 to £3 per day.

peedee


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## artona (Jan 19, 2006)

I don't know why all cls don't have meters. The whole idea (from the campers point of view   ) of a cl is cheapness ( and quietness) . 

Its illegal to sell electricity on at a profit. A campsite could get away with an admin fee maybe but if they pay the elec board £3 a night thats all they can charge, legally.

Many campsites charge a nightly fee which includes "free" elec. I think this has been pushing the nightly fees up. I would much rather pay say a fiver a night and then have an option to pay for the electricity on top at precisely the cost of useage if I want plug in. I would not object to say a 20% charge on top to cover admin and maintanance of hook up points etc

stew


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## tviall (May 1, 2005)

184w for a Truma heater doesn't sound right. 

I haven't looked at the paperwork but I believe my Truma heater is 2000w which is you leave on for 24/7 would costs approx £4.80. And then on top there's the water heater which is another 2000w, kettle, lighting, etc etc etc .

In reality of course this doesn't happen. The thermostat will turn the heater off and you don't have the water heater on the time. So the best way of looking at this is time see what a £1, £2 and £3 of electricty looks like.

At 10p per kw/h £1 equates to 10kw for 1 hours or 416w each hour (over a 24hours period). £3 equates to 30kw for 1 hour or 1.25kw each hour.

In my van, which uses the Truma convertor fire with the 2kw electric heater, separate Truma water heater with 2kw heating element, 2kw kettle plus lighting I could easily use on average 1.25kw per hour. ie £3 worth of electricty.

You mention that your Truma has an electric consumption of 1.3A. I can only assume that this relates to the power consumption for the fan and not any electric heating element.

I hope that explains things .

Tony


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## DABurleigh (May 9, 2005)

And for future use, squirt some WD40 on that rusty Ohms Law: W=VxA not W=V/A 

Dave


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## spartacus (Jul 10, 2008)

Just to clarify, my van has only blown air heating (no convector) and the Truma manual quotes as follows:

Rated thermal output (automatic output levels) 
Gas operation 
Combi 4 E: 2000 W / 4000 W 
Combi 6 E: 2000 W / 4000 W / 6000 W 
Electrical operation 
Combi 4 E / Combi 6 E: 900 W / 1800 W 
Mixed operation (gas and electrical) 
Combi 4 E: max. 3800 W 
Combi 6 E: max. 5800 W 
Gas consumption 
Combi 4 E: 160 – 320 g/h 
Combi 6 E: 160 – 480 g/h 
Readiness-heat power requirement Combi 4 E / Combi 6 E: 
Gas operation 5.2 g/h 
Air delivery volume (free-blowing without hot-air pipe) 
Combi 4 E: with 3 hot-air outlets max. 249 m³/h 
with 4 hot-air outlets max. 287 m³/h 
Combi 6 E: with 4 hot-air outlets max. 287 m³/h 
Current input at 12 V 
Heater + boiler 
Combi 4 E: Short-term max. 5.6 A 
(average power consumption 1.1 A) 
Combi 6 E: Short-term max. 5.6 A 
(average power consumption 1.3 A) 
Heating up of boiler: 0.4 A 
Stand-by: 0.001 A 
Heating element FrostControl (optional): maximum 0.4 A 


Mine is the 6E with a rated thermal output of 1800W on electric. This doesn't mean that it runs at full bore all the time though surely?? Once up to temperature the fan will blow the heated air around whilst the element clicks in and out??

Stews idea of an Owl energy meter is a good one (although more stuff to cart around) but in the mean time I'm trying to figure out a rough figure for what I'm using. If it's panning out at £3 - £5 a day that's more energy than I'd use in a house so doesn't seem sensible :?


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## spartacus (Jul 10, 2008)

Thanks for that Dave, it confirms Peedees figure   WD40 now applied  

On that basis 1800W/1.3A running all day comes out at 74p for the full 24 hours.

So around a £1 a day for total electricity usage can't be too far out can it????

Agree with Stew that a low site fee and separate sensible cost for electricity is a better way to go. I was paying £8.50 a night on the CL in question (based on weekly/long term stay) so another £3 made it too expensive.


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## DABurleigh (May 9, 2005)

OK, well two further things.

1) You have also confused A @ 240V with A @ 12V, which really screwed your power consumption sums 

2) Your heating element power specs say NOTHING about duty cycle (thermostat switching) so without a wet finger estimate cannot be used to calculate average consumption.

However, for winter use if you are using mains heating (even in part through dual fuel) don't bother about kettle, battery charging and even water heating, as space heating will easily dominate your electricity consumption.

Dave


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## teal (Feb 23, 2009)

I got one of those meters from the Brutish Gas which tells you how much and amps/volts/watts. You input your average consumption which in our case is .09pa per kw.Now i had this gadjet near my work station and looking at it at times wife was cooking or D/W W/M going and it frightens you.It showed sometimes we were using £70 per week. Had it there for couple of weeks and it went into a cupboard.


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## rowley (May 14, 2005)

Spartacus wrote--On that basis 1800W/1.3A running all day comes out at 74p for the full 24 hours.

On that basis your unit charges must be low.


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