Autosleeper/fridge/electrics problem

Post by **kentishvanman** » 02 Jun 2008, 10:49

Help required please.
1988 A/sleeper. Control panel for water pump/fridge etc.
Fridge-- fuse & holder get very hot, too hot to touch when on 12 volt. Fuse is 10amp as printed on the panel. Fuse holder ok, fuse a good fit. Fridge is new Electrolux RM 4211 (replaced RM212)
Fridge h/book says energy consumption on 12v is 100watts & use a fuse of 16a max.
The old fridge, same power consumption, worked fine on 10a fuse.
Unsure about increasing fuse size as don't wish too set things alight.
Has anyone else got a fuse higher than 10a in their fridge line?
Don

Post by **jamesc76** » 02 Jun 2008, 10:57

before you do anything i would check resistance levels on all the wireing somthing aint right for it to get hot are all the connections clean how old is the wire etc??

Post by **Mocki** » 02 Jun 2008, 11:00

dirty connections get hot.
like james said...... check the connections, and clean them

Post by **kentishvanman** » 03 Jun 2008, 19:10

Thanks Mocki/James for suggestions.
Had checked for dirty connections but checked again. All wiring is in v.good nick. Connections to fuse holder and switch are all soldered ones on the back of the panel. Even swapped the fuse holder for another one today but it still gets hot. Takes about 2mins to start getting warm and after3/4mins fuse is too hot to hold when removed from holder. Only the fuse and holder get hot every thing else, no change.
The relay gets vaguely warm but I would think that's normal. Am tempted to put in a higher fuse and see if that runs cooler. I can do it with the panel off so I can keep an eye on things. Waiting for other A/S owners to let me know what fuses they have. It left the A/S factory with a 10a fuse fitted despite the Electrolux book saying it needed a 16a one. I never had any problems or perhaps I just never noticed it got hot.
Don

Post by **Nicola&Tony** » 04 Jun 2008, 06:46

kentishvanman wrote:Waiting for other A/S owners to let me know what fuses they have.

Have been out and checked, we have a 10 amp glass fuse in our control panel. I don't know if the fuse holder or control panel gets hot when running on 12v because I'd be driving the van at the time. It's usually Nicola that switches the fridge off 12v as soon as the engine is turned off and she's never said anything about it being warm to touch.

Tony

Post by **vwsween** » 04 Jun 2008, 20:04

Had an 86 autosleeper and now a 91 one. Old one had a control panel where you accessed each fuse individually but the latest one has a sliding panel to access all fuses at once. The 91 van has a RM212 and 10a fuse (think the old one did as well) I dont have an autosleeper manual for the new van but the old one said that if using a higher rated appliance then not to exceed 12a. I dont know what is causing excess heat but the fuse rating should be 10a. They can get a bit warm but not hot.
Brian

Post by **kevtherev** » 04 Jun 2008, 20:37

The wiring for your old fridge sounds like it's being worked too hard by the new fridge

Is the wiring ok and not grounding anywhere?

do you need wiring diagrams for the new fridge?

the old fridge was 95 watt on 12v and the new one is 100 watts

according to calculations the new fridge draws 8.3 amps the old one drew 7.9 amps

so in theory the new fridge is a direct replacement as you say.
so the fault lies in the wiring... or a faulty element

Post by **kentishvanman** » 05 Jun 2008, 20:37

Kev, Just done a continuity test on wiring and all seems ok.
I would have thought the prob. had to be after the fuse but correct me if I'm wrong.
There is no break,or earthing, on the red, from relay to switch, switch to fuse, fuse to relay, relay to fridge. Tried a bigger fuse that got hot as well, so did the relay. Could a faulty relay cook the fuse? I had this problem just before the old fridge packed up. I have the wiring diagram that is in the Electrolux handbook.
I am booked into a Auto Elecs on Tues but I would like to find the fault before then.
Don

Post by **ozzy** » 05 Jun 2008, 22:37

10 in mine

Post by **AngeloEvs** » 29 Jun 2008, 00:21

The fuse rating for three way fridges was upgraded to 15A by the leisure conversion industry. The nominal current draw at 12V on the series 1 is around 7.5A but will rise to 8.6A at 14V. Later series 3 way fridges have a 100W heating elements and the current draw can exceed 9.4 amps as the alternator voltage fluctuates. Fuses rupture by heating and melting the fuse wire at the indicated fuse rating, this is why the 10A will begin to heat (even on the series 1). You should use a 15A fuse as indicated in the instructions and anyone with a 10A could replace theirs quite safely to give the fuse link a bit more thermal headroom (if the fuse holder shows any signs of heating). I use 15A for the RM212.

Post by **Nicola&Tony** » 29 Jun 2008, 07:57

AngeloEvs wrote: Later series 3 way fridges have a 100W heating elements . . .

Just out of interest, what is the Wattage for the heating element on the RM212 fridge?

Tony

Post by **kentishvanman** » 29 Jun 2008, 08:03

Thanks AngeloEvs for that info.
I managed to solve the problem just before I went away, for a drive round Norfolk, and havn't had time to post solution since returning.
The problem was the fuse ie. duff. I had changed the fuse, several times, but all my fuses were from the same shop; well known chain of motor accessories suppliers. Local auto elec changed the fuse - problem solved. Will buy my fuses elsewhere in future. He also confirmed, as you state, that the fuse was running pretty much at it's max. and that uprating to a 15amp would do no harm. I am still on the 10amp fuse and it does get warm but not as hot as it used to.
Supposed to be clearing the rubbish out of the van now instead of playing on the 'compooter' so that I can try and go to the VW show at Paddock Wood today. Anyone else going?
Don

Post by **Nicola&Tony** » 29 Jun 2008, 08:09

Just checked the RM212 manual and found the answer to my question

"the boiler of the cooling unit is fitted with two separate heaters . . . the 12V heater is rated at 95 watts and the mains voltage heater is 100 watts."

Tony

Post by **AngeloEvs** » 29 Jun 2008, 10:24

The RM212 series fridges have 12v 95W and 240V 100W elements as Nicola and Tony state. The later models have 12V 100W and 240V 125W elements. The best way to improve the efficiency of the 12V option is to use a heavier grade cable capable of carrying a minimum of 20/25 amps. The cable on some installations has a pretty long distance to travel before it gets to the element, sometimes via a fuse panel then all the way back to the fridge. A volt drop of just 1V results in a noticeable loss of heat transfer, in practice the volt drop could be higher than this and your 10A fuse is very happy with this voltage drop since less current is being drawn by the element. Heres an interesting alternative, with the improved efficiency of inverters, many caravanners are using them to run on the 240V option (instead of the 12V) when driving. The claimed advantage is a much lower power loss to the 240V element and the benefit of having the thermostat to control the temperature.
The 240V Elements are listed here if ever you need one:-

http://www.leisureshopdirect.com/carava ... idges.aspx

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