buz Posted July 13, 2012 Share Posted July 13, 2012 please can any one help ive tried instaling the above fridge freezer into my caravan to work on 12 volt but it wont work any ideas :'( Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 13, 2012 Share Posted July 13, 2012 I assume you realise it will only work on 12V when the towcar is attached and electrically connected, and its engine is running? You describe it as Electrolux. Is this an old, or second-hand, fridge, as they have been branded Dometic for some years? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 13, 2012 Share Posted July 13, 2012 The Dometic RM-6505 is an AES fridge/freezer that selects 230V, gas or 12V operation automatically according to what power-source is available. Because of this I'm not really sure what your description of the problem means. Does the appliance not work on 12V, but works OK on gas or 230V? These are complex products and the problem may be due to something simple - like a blown fuse or a failed 12V heating-element - or it may be due to a fault with the appliance's electronics. Presumably you understand how this Dometic model is supposed to work? If you haven't got a instructions manual for it, then you can find one here http://ebookbrowse.com/dometic-rm-6505-pdf-d132643975 Link to comment Share on other sites More sharing options...
buz Posted July 13, 2012 Author Share Posted July 13, 2012 yes its a 2004 fridge freezer and i was told it would work in the caravan with a 225amh battery when connecting it its hunting for gas and even when i connect to the varible solar power it wont work Link to comment Share on other sites More sharing options...
buz Posted July 13, 2012 Author Share Posted July 13, 2012 yes im not that clever with that type of electrics i havent opened up the black box up are the fuses just standard or do they need soldering in Link to comment Share on other sites More sharing options...
buz Posted July 13, 2012 Author Share Posted July 13, 2012 its in a mobile caravan thats static Link to comment Share on other sites More sharing options...
Keithl Posted July 13, 2012 Share Posted July 13, 2012 Buz, According to the instructions on the link posted above it will only work on 12 volts when it senses the vehicle engine running by the voltage on terminal D+. I quote from page 13... 12 V Operation AES will select the 12 V mode of operation only when the vehicle engine is running (detected by the alternator connection of the fridge D+). Therefore you will need to supply a voltage of probably in excess of 13 volts to this terminal before the fridge will run off your 12 volt battery. (EDIT) OR DOES IT ONLY NEED TO SENSE 12 VOLTS? IN WHICH CASE IT MAY WORK (EDIT 2) TRY CONNECTING 12 v+ TO D+ AND SEE IF IT WORKS. (I've used CAP's to highlight my edit). In short very sorry but you may have been sold a pup :'( Finally how long did you expect it to run from your 225 Ah battery? According to page 19 it will consume 175 Watts, or to put it more appropriately nearly 15 Amps! This will drop your battery to 50% charge (the minimum recommended) in around 7 hours! In other words probably not worth bothering with :-( This is confirmed by the quoted "Energy consumption (in 24h)" of 3 kWh or dividing by 12 volts gives 250 Amps in 24 hours! Hope this helps (or not as the case may be), Keith. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 14, 2012 Share Posted July 14, 2012 buz I have a 2005 Dometic RM-7651L fridge/freezer in my motorhome. This is a non-AES appliance, but its basic wiring will be similar to a RM-6505’s. First things first – these appliances are not intended for use in a static caravan and the AES models are particularly unsuitable for that type of installation. Referring to Keithl’s posting, to allow the appliance to operate on 12V DC you MUST provide a power-feed to the appliance’s D+ terminal to simulate an ‘alternator signal’. I’m pretty sure that any voltage above 12V should be adequate for the power-feed, so just providing a connection from your 225Ah battery to the D+ terminal should be OK. For the main DC power-supply to the RM-6505 you would need to use cabling with a substantial cross-section – Dometic advises at least 10mm-squared. However, a stand-alone 12V battery that is not being charged may not provide a high enough voltage to cause the appliance to select DC power. A vehicle’s alternator will produce a voltage of around 14V, whereas the voltage of a fully-charged 12V battery will not exceed 13V. Consequently, if an RM-6505’s electronics demand above 13V for the appliance to run from a DC power-supply, it will not be possible to operate an RM-6505 from a stand-alone 12V battery. This restriction is highlighted in the following paragraph “Undervoltage operation The AES system is designed to guarantee the maximum cooling efficiency under any circumstances. Therefore, the system monitors continuously the voltage level while being in either 12 V DC or 230-240 V AC mode. If the voltage is too low, the system switches to Gas mode shown by the yellow LED (E in fig. 1.). The system stays in Gas mode, until the electrical supply voltage has recovered to normal level.” Even if an RM-6505 would operate from a 12V battery, (as Keithl says) the appliance’s Amperage requirement is so high that even a 225Ah battery would be rapidly discharged. To keep up with the demand, you’d need an input to the battery of over 14A. This is easily available from a vehicle’s alternator, which is where Dometic designed the RM-6505 to obtain its DC power from. I think there’s little likelihood of you being able to operate an RM-6505 successfully from a 12V battery. You should be able to operate it on gas or on 230V (though, in both cases, you’d also need a 12V supply to power the appliance’s electronics). You say that you were told that the fridge/freezer would work from a battery. I suggest you ask “How?” from whoever told you that. Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 14, 2012 Share Posted July 14, 2012 But, even if it can't be operated from 12V while static, it should still operate quite satisfactorily on 12V when being towed, which is how Dometic intend the 12V supply to be used. It seems there is no 230V available where you are, so your best bet will be to operate the fridge on gas. You have a large battery plus solar, so the current required for the gas circuitry will be well maintained. So, I suggest you just drop the idea of trying to run this fridge from 12V while your van is static. With the 12V consumption level of this fridge as high as it is, it is unlikely your solar panel would keep up with its demand, especially if you intend using it in winter when solar panel outputs are sharply reduced. I think it would gradually flatten the battery in a matter of a day or two at best, because the fridge would be taking more out of the battery than the solar panel could put back. In fact, unless you have a truly massive solar array, I doubt any three way fridge could be operated year round as you were hoping. They just use too much electricity. But, used on gas, it should be fine. Link to comment Share on other sites More sharing options...
buz Posted July 15, 2012 Author Share Posted July 15, 2012 yes thanx for all the replys its looking like its gonna have to be used on gas i just dont like the idea of co2where kids are as there are no vents in thefridge area illl have to install some thanx again Link to comment Share on other sites More sharing options...
Keithl Posted July 16, 2012 Share Posted July 16, 2012 Buz, Make sure the rear of the fridge and especially the flue is 100% sealed from the living area as the CO is the killer. (It's actually CO and not CO2 that is produced, and it's odouless!). You would probably have needed vents at the rear of the fridge anyway as these fridges work on a different principle to yourusual domestic item and have to have an adequate flow of air over their cooling fins to work. It would be worth checking the installation instructions very carefully for details of what is required. All the best, Keith. Link to comment Share on other sites More sharing options...
buz Posted July 16, 2012 Author Share Posted July 16, 2012 yes thanx thats what is worrying but now i know i can star to swork out what will be best way to do it tanx again to all for the advice and help given Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 17, 2012 Share Posted July 17, 2012 If you get onto the Dometic website you will find you can download the installation and operating manual for your fridge. Probably, the instructions will cover several models, but they are very clear with good illustrations. The simplest way to get the ventilation right will be to buy a pair of Dometic vents. One to go high up, the other low down, behind the fridge, through the external wall of the van. Don't try operating it on gas without these vents, of it probably will generate CO into the van! In normal use, when properly ventilated, the gas will exhaust safely through the upper vent. Most of what comes off is water vapour, with a small amount of harmless CO2. As your fridge was second-hand, I'm wondering if it will have the necessary flue terminal. Comparing the illustrations in the manual with the back of the fridge should show you if it is there. If it is not, you'll probably have to contact a Dometic agent, or Dometic direct, to get one. Make sure you note exactly the fridge model number and also its serial number if you have to do this. The manual will make clear where all these can be found. It seems the fridge will have to come out so that you can install the vents. It's never easy, is it? :-) Make sure you carry out the sealing around the back of the fridge as they describe. Heat escapes into the van interior if you don't, making it hotter in hot weather, but also, due to the size of the vents, you'll get a howling cold gale into the van in cold weather, and you will also get some fumes and niffs from the back when it is on gas! Properly installed, they are good, reliable, bits of kit and work well. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 18, 2012 Share Posted July 18, 2012 There is a specific Dometic manual for the RM-6505 - I provided a link to it earlier in the thread. I echo Brian's advice. The appliance needs to be correctly installed (I suspect it's currently just 'free-standing' in the caravan) for it to operate safely and efficiently on gas. I think (as with my own fridge-freezer) the fumes from the gas-flue exit directly into the void behind the appliance, so sealing the rear of the appliance from the caravan's living-area is vital. Link to comment Share on other sites More sharing options...
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