Fridge operation

[Smith21]

I have been messing about with things testing the heater, oven, grill, and hop etc. I tried the fridge on the 12 volt system but it would not switch on and the indication light did not illuminate. I think there was about 12.5 volts on the battery gauge.

Should the fridge have worked or does it need to be down to temperature using 230volt first or do the outside covers have to be removed before it works.

 

[SteveW77]

The fridge does not work off of the caravan battery, the 12volt setting is for when the van is connected to the tow car and then only with the engine running.

Steve W

 

[Smith21]

The fridge does not work off of the caravan battery, the 12volt setting is for when the van is connected to the tow car and then only with the engine running.

Steve W

Thank you Steve W that explains why it would not work.

 

[Mikey_74]

Just another quick note Kevin, as already stated the fridge will only work on 12v when connected to the car (white socket on the tow car) with the engine running, but it's also worth noting that there isn't really enough power in the 12v system to get the fridge cold, but the night before you travel or at least a few hours before if you run the fridge on either gas or 240v then the 12v system will maintain a cold temperature.
I hope this helps and makes sense.....
Mike

 

[Smith21]

Cheers Mike will bear that in mind before we go on our outings.

 

[Damian]

There should be no discernable difference between running the fridge on mains or 12v, or gas for that matter.
The mains element is around 125w and the 12v element is 120w.
The difference is the 12v does not have a thermostat so will just get colder and colder, BUT it depends how long a trip you do as to how effective it is.

 

[colin-yorkshire1]

hi Kevin,
not wanting to contradict Damian as he is the font of all knowlege on these things, I must add unless you are going to the south of france in one go without stopping it is unlikely that the fridge will cool suffiently in a trip from home to a site say done in a couple of hrs,
if food is to be stored in the fridge during the journey you really should cool it down first with gas or EHU, for 24 hrs
dont forget if the car stops so does the fridge so that 45min stop at the services in hot weather will have an effect on the efficiency of the fridge.
edit,
a journey from home to cornwall takes us 10 hrs with stops if the fridge is not cooled first, and then checked on arrival the fridge will be at operational temprature ie 5degrees but the freezer box will not have iced up yet, so the time scale for it to cool down completely must be suspect.on short journeys and the reason most say 12v is ineffecient.
colin

 

[ProfJohnL]

Hello Colin,

Perhaps some may say I'm splitting hairs, but the 12v element is no less efficient, than the gas or the mains. It the circumstances in which it is used that may make it seem less efficient.

The reasons you give are correct, but in addition and by the nature of the power being derived from the alternator which only produces power when the engine is running which surprisingly is also when the outfit is also generally moving, the fact that the caravan is moving through the air also means the activity of the 12V element may be being somewhat compromised.

Few people can accurately predict how the air flow around the fridge vents will interact with the convection heat from the element and the condenser coils. A situation that will be constantly changing under towing conditions.

If the caravan were stationary, then it is unlikely you could detect any significant difference between the three fuel sources, except that the 12V may take the fridge cooler as it is not thermostatically controlled.

 

[colin-yorkshire1]

hi John,
no it is not spitting hairs you are correct, it is just the fact that when the engine stops so does the fridge a similar situation could be seen if the fridge was turned off for 30mins every 2hrs while running on gas, but no one would do that,
on the other hand if the fridge was at proper temperature before setting off on a journey of say 1 to 2 hrs and the fridge was left unconnected it coulld well be cool enough by the time one arrived providing it was left shut, like a cool box,

 

[Smith21]

Thanks for the reply's another fridge question if I may, when towing with the fridge turned on do I need to remove the covers from the outside of the van or are these only removed when using gas.

 

[TD42]

Hi Kevin, the fridge covers are only meant to be fitted at tempetures 10 degrees & below which is why they are some times known as winter covers.
But the cover on the exhaust of the Water heater MUST be removed if you use gas to heat your water

 

[colin-yorkshire1]

hi Kevin, TD42 is correct as there is no clear instructions on the use of winter covers we all have our own way of deciding when to fit or not, some who never use the van in winter never fit them at all,
however I take a more pragmatic view. when the van is stored they go on, they come off when cooling the fridge down for 24 hrs before a trip, and then go on again for the journey " this counteracts some of the effects John spoke of earlier" on site they come off and stay off unless the temp drops to near freezing, and then go on again for the journey home, if moving from site to site on tour I usually just leave them off, but they are allways with the van.

colin

 

[Gafferbill]

.......the Prof is spot on with his post as to why most people think a caravan's fridge performs less efficiently on 12 volts.
That is to say there is too much air passing the vents giving too much cooling to the heater element when towing.
Stopping on route will also effectively switch the fridge off which also does not help.
Wiring that causes a voltage drop can also reduce performance.

I always tow with winter vents fitted whatever the ambient temperature for this reason.
My fridge has also been modified to keep running when the tow car engine stops and it then runs from two 110 amp hour batteries.

 

[mealsonwheels]

Hi Kevin
I can endorse all that has been said about getting the caravan fridge really cold well before a journey. We get our caravan out of storage and put it on the drive about 4 days before we set off, plugging the electric hook-up lead into a 3pin socket in the garage. We get everything that we want to take in the caravan fridge really cold in the house fridge first and then put it into the caravan fridge the day before we set off. The freeze box (if you have one) above the caravan fridge should not be used to freeze food, the food put in there should be frozen first. The most important thing is not to overload the caravan fridge, but leave room for air to circulate around items.
A lot of caravan fridges are on the same side of the caravan as the awning goes and vents out into it. This can cause it to struggle when the weather is really hot and the awning is left zipped up, trapping heat. We have fitted fans to the back of our fridge to help with the flow and our awning (Bradcot) has strong mesh in the windows, so you can roll up the outer acrylic window at each end and allow air to flow through the awning when you're out. It can also help to take the awning skirt off that runs the length of the caravan, below the door. Some caravan doors open out, covering the fridge vents, which doesn't help. You can buy fridge thermometers which can be placed on the front of a shelf, which will give you a good idea of how cold it is.
We now put beer in a cold box in the awning. Some of them run off 12v too.

 

[Dustydog]

Hi Kevin
Assuming you have the 12N and 12S plugs rather than the newer 13 pin you maywish to consider this modification
http://www.towitall.co.uk/faq/1.aspx
Since doing mine some years ago the 12S has never suffered pin burn out.