Fridge power requirements

Hello. The fridge in my campervan (used) doesn't have an external on/off switch, doesn't have an accessible fuse on the 12v board. So it is always on, and the previous owner just used the internal rotating power selector as an off switch by turning it to zero,

Is an on /off witch an easily accessible fuse the "normal" way to wire the fridge into a conversion?

Thanks for your comments.
 
I think you will find that zero is off.
I’m guessing it’s a compressor fridge in which case you will hear the compressor running if it is working.
 
Normally the O/I switch is in the fridge, have you got the manufacturers manual?
 
Thank for the replies.
Turning the power setting to 0 does cut the compressor off. My fear of using this is wear on that part whereas an external on/off is a cheap replacement.
The fridge is an Indel B, I don't have the model number and was not given a manual. I can not see any other switch inside other than the hanging "4 setting one" with the zero on it.
Fuse wise, I presume there will be, or should be, an inline fuse behind the fridge?
 
Last edited:
It’s a thermostat, which is in effect a variable switch. There won’t be any wear in switching it to zero.
I briefly worked for a company that mass produced fridge thermostats, the gold coated contacts were designed to last 1 million cycles.
 
I see lots of posts asking how long will my leisure battery keep my fridge in the van running.

There are a few variables to consider.

How much capacity your battery is , eg amp hour size. You should only use about 1/2 of your battery capacity regularly , (unless it is a lifepo4 lithium battery, ) to avoid shortening its life. So a 100ah battery allows around 50ah to be used.

Current draw of your compressor fridge when compressor is running.

Importantly , Ambient temperature as once your vehicle heats up inside your fridge compressor runs a lot more, to the point of continuous running.
.My fridge in cool weather hardly runs much at all so over 24 hours doesn't use a lot of battery but in hot weather, van interior over 30c it runs almost continuously so will use around 40+ amphours each day.
You also need to run the fridge at a lower temperature setting and this makes the compressor run more too.
Without putting charge back in the battery it would only last a day and a bit before battery voltage drops too low.
Your choices are
Run the van to recharge leisure battery.
Hook up to 240v, if you have a charger onboard, and have access to 240v.
Have solar recharging leisure battery.
Solar is the best option in my opinion if you are traveling around and stopping for a few days and not driving the van.
Fixed panel/s on the roof are the easiest to use as its always inputting when in the sun.
Solar blankets and portable panels work too but you must set them up and move them to face the sun regularly.
I use a combination of both.

The problem relying on solar recharging your leisure battery is when you get multiple days of cloudy or rainy conditions without sunshine. That is why you need the biggest amp hour battery you can fit if considering extended travel.
I eventually fitted a lifepo4 lithium battery and more solar panels to give us the backup power for travel. Lithium lifepo4 batteries can be drawn down much deeper without damage so that gives you more battery reserve to use.
These are my observations and may be relivant to your use of your van.
 
If it helps anyone on fridge power consumption, we have a dometic crx50 set as a fridge with the temp on middle fridge setting, I think 3degC throughout the year. We run this fridge since summer 2019, and only got switched of 3-4 weeks this winter as we did not used it. The consumption based on victron monitoring via battery monitor and vrm portal, it eats about 300wh per day in summer months, reducing to about 240-260wh during cold seasons. We are a midd age couple and don’t open the door more than necessary. The fridge cupboard is off the floor about 200mm and top height about 900mm. The sides have a 50mm air gap, same as the back. Around the door, there is a 5-6mm space between the cupboard and fridge. This allows air into the back where compressor is located. Above the compressor there is three 50mm vents pointing up, and one to the side. Hot air from compressor area escapes up and new air enters via door surround. This cross flow ventilation works well and keeps the temperature down at compressor and rad area. I initially wanted to fit a dc fan to exhaust air from the back, but the air flow is pretty efficient as it is. I know cases with same fridge with higher consumption. This is because the cupboard does not vent enough, and compressor works harder and longer cycles. Another think I added dodo mat inside the cupboard and hard foam blocks glued to fix it in; no screws no vibration sent to the box and super silent.
 
I have had trouble with my Dometic Crx50 fridge which is connected through my Sargent unit.
I want to connect it directly to my leisure battery using 4mm2 wiring.
I having a problem finding a suitable in line fuse, the best I've found only has 3mm2 wire, given that the cable rim is going to be a lot shorter than my existing setup, is it likely to be a problem? Any help would be greatly appreciated.
 
raylacey said:
I have had trouble with my Dometic Crx50 fridge which is connected through my Sargent unit.
I want to connect it directly to my leisure battery using 4mm2 wiring.
I having a problem finding a suitable in line fuse, the best I've found only has 3mm2 wire, given that the cable rim is going to be a lot shorter than my existing setup, is it likely to be a problem? Any help would be greatly appreciated.
Click to expand...
In line fuses aren't the best, especially when the cable on the battery side is not protected. Best to fix something down properly, and shield the cable from any damage.

Regardless of that, if the fuse holder a very short piece of 3mm² wire, and you join some 4mm² or 6mm² onto it to run to the fridge, you don't need to worry about volt drop, it's proportional to the cable length, so the very short part of the cable has negligible volt drop.

Make sure any joints are clean and sound, this is where you could improve (or screw up) the volt drop. Blade fuses are better than the crappy inline glass fuses.
 
have a look here:

www.t6forum.com

Diagrams, Schematics & Wires -- How I Done It --

Diagrams, Schematics & Wires -- How I Done It -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...
www.t6forum.com www.t6forum.com


and

www.t6forum.com

Diagrams, Schematics & Wires -- How I Done It --

Diagrams, Schematics & Wires -- How I Done It -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...
www.t6forum.com www.t6forum.com

1646402237290.png
 
T6Jay said:
In line fuses aren't the best, especially when the cable on the battery side is not protected. Best to fix something down properly, and shield the cable from any damage.

Regardless of that, if the fuse holder a very short piece of 3mm² wire, and you join some 4mm² or 6mm² onto it to run to the fridge, you don't need to worry about volt drop, it's proportional to the cable length, so the very short part of the cable has negligible volt drop.

Make sure any joints are clean and sound, this is where you could improve (or screw up) the volt drop. Blade fuses are better than the crappy inline glass fuses.
Click to expand...
Thank you T6Jay,
That's what I needed to know, I was planning to use a large in-line blade fuse but couldn't find one that matched the 4mm2 wiring, 3mm2 waterproof holder (you never know!) it is.
Thanks once again.

Ray
 
As previously mentioned, its volt drop. The fridge cuts out at a certain voltage so best to get the max voltage at the fridge end as possible. If you really dont want to buy thicker cable you could double up the smaller cable you have thus increasing the CSA. And before people attack me for 'this is a bodge', We wouldnt do this on vans, however in a previous life as an industrial electrician we installed 3phase systems often and the largest we did was 3 x 150mm single cables per phase (equating to 450mm2 per phase) to a swimming pool. So this practice is possible and not a 'bodge'.....:p

Cheers
 
Eclipse Custom Vans said:
As previously mentioned, its volt drop. The fridge cuts out at a certain voltage so best to get the max voltage at the fridge end as possible. If you really dont want to buy thicker cable you could double up the smaller cable you have thus increasing the CSA. And before people attack me for 'this is a bodge', We wouldnt do this on vans, however in a previous life as an industrial electrician we installed 3phase systems often and the largest we did was 3 x 150mm single cables per phase (equating to 450mm2 per phase) to a swimming pool. So this practice is possible and not a 'bodge'.....:p

Cheers
Click to expand...
This is totally legit, not a bodge at all.

I would add however that in a van application the fuse must protect each individual cable size, not the sum of the CSAs.

I know this isn't always the case in industrial applications.
 
I am considering wiring my 12v fridge to my switch panel, just so I can see what is on and off, is there any issues with this as opposed to wiring straight to battery
 
Adding a switch will add to the voltage drop in the circuit but as long as your cable run is short and sized accordingly you’ll have no issues. It won’t flatten your battery quicker
 
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