Running caravan fridge on Solar panels

[stevesnrs]

Hi
it depends on how old the caravan is
this is a 2007 swift challenger model which may have a caravan or car supply switch, later models are fitted with a habitation relay that does exactly what you describe and cuts off the caravan battery when the car is connected

 

[colin-yorkshire]

hi all.
Dusty is right in 40+ years of caravanning I have never known a fridge run off the 12v system exept for the purpose of keeping the fridge cool while travelling, in the early days fridges were gas only,
on the invent of 3way fridges, the wiring of vans was altered to inc a grey plug in order to supply power to the fridge and by now the leisure battery fitted to most vans because the blue (aux wire used for internal lights) left in the black plug was no longer sufficient to supply enough current, this wire was switched to power fog lights.
from this point on the 12v supply to the fridge was a direct link to the grey plug controlled by a relay on the towing vehicle, so unless the van is pre modification the habitiation switch cannot supply power to the fridge as it is not connected to the 12v supply.

now to use a phrase anything is possible (although one would have to be extremely bright to work it out) one could power the fridge using solar panels by using the current via a controller direct to the grey plug (or 13pin) that supplies a direct feed to the fridge, :woohoo: now wether this would be sufficient to be effective is an open question. at least it would not involve flattening any battery.

unfortunatly the OP seems to have forgotten the basic premiss of caravanning and that is compromise while anything is possible it is not really necessary with a bit of thought and compromise one can get round any problem it is a question of priorities, is it more important to be off grid than have in IMHO the unfounded worry of children sleeping in the awning near the gas vents.
either 1. use EHU,
2. turn off the gas at night.
3. use an extra porch awning as a sleeping tent on other side.
or 4. leave the kids at home :evil: (only joking hmy: ).

 

[stevesnrs]

Hi all,
reading back through this discussion, it seems the usual thing is happening, which is, someone asks a reasonable question, and sooner or later everyone is discussing something completely different, and the question never gets answered.
johnandrew70 asked if he could run his fridge from solar panels.
He did not specify mains or 12v.
My reply clearly explained that he could NOT run his fridge on 12v as the panels would not be powerful enough.
The comments about the electrical systems whist towing are irrelevant, as the van would be parked up and disconnected from the towing vehicle.
I also stated that "if" he had the old type panel with the ability to choose the "van" or "car" battery function, he could run from the van battery as my friends do.
I have just returned from a trip to France with friends, one has a 2007 Bailey ranger, and the other has a 2006 Abbey. Both have the panels with this function.
Both these friends disconnected their electrics from the car on the overnight ferry, and switched their panels to the "van" setting on the control panel, which allowed them both to run the fridge on 12v overnight. It didn't matter if the batteries were flattened, as we had a long drive, and hook ups when we got to site. Next morning the panels were reset to "car" and the fridges go off, until the car starts up and the fridge comes back on again.
I cannot see how two different vans from two different manufacturers can act the same way, if this function was not "standard" on these old panels.
The previous year, when they did this I didn't think it could be done, but they proved me wrong and showed me the fridge working on 12v no car connected, whilst we were on site.
Therefore IF johnandrew70 has this function on his control panel it might be the same, but as its a swift he would have to check himself.

 

[RogerL]

It comes down to whether the fridge is wired correctly, according to Electrolux/Dometic or Thetford and whether the wiring has been modified.

I doubt any UK caravan brand ever wired the fridge intentionally incorrectly - so it'll only take power from the car's alternator, never the caravan battery - and never the car battery unless wired incorrectly.

I've seen reference a long time ago to modify the caravan wiring to take a feed from the leisure battery and terminate it with a 12S socket into which the caravan's 12S plug fitted - a modification to allow the leisure battery to run the fridge but a modification nevertheless - probably not very efficient as the current draw would drop the voltage down below 12v while an alternator-powered fridge would run at around 13v, which is 14.4v at the engine but subject to voltage drop because of the distance.

 

[colin-yorkshire]

hi, yes I agree Roger, I have a 2005 ranger and it is an automatic function the 12v wires from the fridge go directly to the plug not to the vans 12v system there is no way to power the fridge on 12v from the vans battery without modification.
I know this as a fact as I rewired the van to 13pin and traced every wire. when the fridge is switched to 12v the only power it will receive is direct from the plug and nowhere else. also as far as I know (although I could be wrong) all rangers from 2000, (when the spec was altered) have an automatic system and as such do not have a habitation switch.
a relay yes a switch no!!

edit, as an aside the vans control panel has only 2 switches "pump on/off" and master on/off,
in the "off" position nothing works,"for when towing" in the "on" position it provides 12v power from the van battery (but only when disconnected from the car) , otherwise no power. I suspect this is why the mentioned owners pull the plug.
however when the master is on "plug disconnected" the red 12v fridge light stays out so the fridge is not working on 12v. (why would it when it is not part of the 12v system) it only comes on when the plug is reconnected and the engine started.

 

[Dustydog]

Hi Roger and Colin.

I fully agree with all your comments. My previous S5 Pageant and current Senator work the same way as Colin's Ranger.
The benefit of a forum is the ability to engage in interesting debate sometimes broadening the OP's original question. Is that really a problem?

 

[stevesnrs]

this is definitely not the way their vans work, as I said I have seen it for myself, you are saying that both the vans have been modified to do the same thing, in the same way, at some point in their life, before the current owners bought them, which makes you wonder how many vans if this is indeed a modification, are running around with the same modification, what would be the odds of them both getting a "modified" van?

 

[Dustydog]

Looking the Senator's handbook it says:
Only use 12v fridge setting when connected to tow vehicle and engine running.
Otherwise caravan battery will be discharged in a few hours.
Now I admit I'm surprised. I was always told to turn off the Master 12v switch on the master panel. Turn the fridge dial to 12v and it will run off the engine.
I will try it out on our next trip.
As I say rereading the manual has surprised me!

 

[stevesnrs]

maybe it is a function that can be used and not a modification, I would be interested to hear if yours works in the same way as my friends do, as your manual more or less says that this function is available, I must admit I wish my van had this function, as they were able to keep their fridges cool on the ferry, while mine didn't and the freezer defrosted!

 

[stevesnrs]

Hi Colin,
You are correct, I have just checked the wiring diagrams on Baileys website, and your model a 2005, powers the fridge directly from the "s" socket pin 7
But on the 2007 models the fridge is wired to a 4 pin plug on the electrical motherboard, and the "s" socket is wired to another 4 pin plug on the same board, so it could be possible for the electronics of the board to allow this function, dependant of the master switch position.

 

[Dustydog]

Just to complicate matters even when the 12v master switch is off the fridge internal light remains on, door ajar or open,.Can only be turned off by fridge off knob.
This foible catches out a lot of people who wonder why their battery goes flat.

 

[stevesnrs]

which means the fridge is powered all the time, as there are only one set of positive and negative wires to the fridge according to the wiring diagram plus the mains wires, the only control is the fridges own control 12v knob?

 

[stevesnrs]

no my mistake there are two more wires, which must power the fridges electronics

 

[colin-yorkshire]

AH the plot thickens, from the descriptions above one would assume the fridges in question are Dometic units,
this could explain the difference, mine is an Electrolux it has on the left hand side (looking at the front) 2 switches one red 12v, and one green 230v, a knob that goes from 1 to 9, and on the right hand side a knob that also goes from 1 to 9, and a gas igniter, (it is actually a flame symbol not 1 but the key board don't do them)
no electronics or fridge light.
if the new units do work in the way described it seems a backward step imo

 

[Dustydog]

Well I 'm blowed.
Looking back I see my series 5 Pageant had a Thetford fridge. The Wyomings is a 115 litre Dometic with removable freezer section.
I'll be away in a few weeks time and will do some tests. I've had her 6 years and thought a knew how everything worked hmy:

 

[RogerL]

Current Dometic fridges have three, independent, sets of wiring - 12v from the leisure battery to run the control system - 230V from the mains for mains power - 12v direct from the 13-pin plug for 12v power

 

[Gafferbill]

......over the years there has been various wiring conventions for caravans that UK caravan manufacturers have followed.
All these conventions have and do employ wiring that only allows the refrigerator 12 volt heating element to receive a supply when the tow vehicle's engine is running and supplying a charge voltage to the vehicle battery.

I am not aware of any UK manufacturer that does not and has not always followed these conventions.

Yes.........most refrigerators receive a 12 volt supply from the caravan's own battery but this is for control systems or lighting.

..........as an aside I have converted my older caravan to allow the absorption refrigerator heating element to be able to run on 12 volts whether the tow car engine is running or not.
My system has an effective duration of up to 2 hours and has involved extensive rewiring of my caravan and tow car.
The main part of the modification being the addition of a second 110 amp hour leisure battery carried on the tow car with extensive use of heavy duty wiring.

To create effective cooling the 12 volt element needs to receive a 12 volt to 14 volt supply of 10 amps.

A single fully charged leisure battery, connected to supply the 12 volt heating element, will have a battery voltage that will drop below 12 volts within about 30 minutes.

 

[Dustydog]

Roger & Bill

You echo my original view.
However Having re read my series 6 Wyoming handbook things may not be as I thought. Why say the leisure battery will discharge in a few hours if left unhitched from the car and set on 12v ?
I will do some tests next month.
My newish Numax 120 amp leisure battery shows 13 v on the Bailey meter. That's when ehu is connected.
Updates will follow.
How does our Woos ie King's Lunar fridge connect?

 

[WoodlandsCamper]

How does our Woosie King's Lunar fridge connect?

Don't know, that's the OH's domain. I do know it's got an LCD display, and a bright blue light which at night which needs covering. I believe she switches it over when towing and also switches between gas and mains. The user manual is in the van at the storage site.

Edit - our fridge is a Thetford N90 and is manual selection. The blue light mentioned above is also the on/off button and the light flashes if the fridge is in a mode it doesn't understand (ie a source is selected when that source is not available). There are two other buttons, one toggles around the input selection (gas, mains, car) and the other toggles the temperature setting (several selection up to coldest and then wraps round to the first end again).
Lunar changed to Dometic the following year. I wonder why?

 

[RogerL]

However Having re read my series 6 Wyoming handbook things may not be as I thought. Why say the leisure battery will discharge in a few hours if left unhitched from the car and set on 12v ?

On my earlier Bailey, 2001, the controls for each fridge power source were separate - so mine was permanently set to run on 12v AND 230V - so change over was "automatic" as I unplugged the car and plugged in the mains lead at almost the same time - the main Car/Off/Caravan selector was permanently set to Caravan.

 

[Gafferbill]

........for anyone interested in Caravan Electrics then Simon Barlow's Blog is a very good website.

He has excellent knowledge of caravans in general and is a source of definitive information for those that require correct information from a reliable source

 

[ProfJohnL]

........for anyone interested in Caravan Electrics then Simon Barlow's Blog is a very good website.

He has excellent knowledge of caravans in general and is a source of definitive information for those that require correct information from a reliable source

Hello Gaffer,
Well informed but not definitive, as he is quoting mains supply at 240V when the standard is 230V !

 

[Gafferbill]

Hello Gaffer,
Well informed but not definitive, as he is quoting mains supply at 240V when the standard is 230V !

Prof .....he was keeping it simple by quoting 240 volts!

The actual standard I believe is 230volts -6% +10% or 216 volts to 253volts

 

[WoodlandsCamper]

Prof is right. For years the UK standard used to be a nominal 240v ac and the continent's was much lower (220v?). However, one of the many things that the EU did for us some time ago was to change our (and Europe's) nominal voltages to a common 230v ac.

 

[colin-yorkshire]

230v or 240v who cares, stick your finger into a light socket your still dead :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: