When should Dometic 3 way fridge shut off? (1 Viewer)

[Dolmen]

I have a 3 way dometic (2021/22) fridge. If it is set to Auto, when I switch the engine off it flashes, beeps and looks for an alternative power eg gas, if the gas is switched off it continues to flash, however, obviously cannot cool. If I have it set to engine battery, when I switch the engine off it beeps and flashes on the engine battery sign. not being on auto it cannot switch to anything else. At this point I either switch the fridge off all together (manually) or if I want cooling then turn the gas on (if it is off). My question is, if I just left the fridge alone would it eventually switch itself off if no power source or would it keep flashing and beeping until there was no battery left. The fridge works in this mode regardless of whether the control panel is on or off. Apologies its a long one.

 

[Lenny HB]

When you turn off the engine it should change/stay on battery for approx 15 min before selecting an alternative energy source.
Sounds like you have a control panel fault, it should still be under warranty as I think Dometic now warranty them for 3 years.

 

[Dolmen]

When you turn off the engine it should change/stay on battery for approx 15 min before selecting an alternative energy source.
Sounds like you have a control panel fault, it should still be under warranty as I think Dometic now warranty them for 3 years.

Thanks for that and that may well happen, I don't know. I have never thought that long to see what happens, will nip out to the van now and check, may well be working just fine, thanks again

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[funflair]

If you have switched it to battery and then turn the ignition off it will stay on battery as that is your chosen power source, if you leave it like this it will flatten your battery was that the question?

You say "if you have set it to engine battery" it doesn't necessarily use the engine battery to run though as it just uses a signal from the alternator to allow it to switch to 12v source when the alternator is producing power.

 

[pappajohn]

If it has no power source I would expect it to continue bleeping indefinately until it does have a source...... Or the battery dies .

 

[denisejoe]

The reason it doesn’t go to gas straight away is because you might be filling in a petrol station

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[Lenny HB]

If you have switched it to battery and then turn the ignition off it will stay on battery as that is your chosen power source, if you leave it like this it will flatten your battery was that the question?

He has a Swift so I don't think that will happen.

 

[Dolmen]

Just been out to check, most things seem OK, ie on Auto, if I have the gas on when I turn the engine off it will switch to gas after a period of time, if I hook up it choses the 240v as priority, if I switch the engine on it changes to engine battery sign. If on manual it will switch to whatever source I have connected and if I switch it to a source not connected the warning triangle will flash and beep. If I have it on manual, source engine and switch engine on it cools as you would expect, if I switch engine off (remember its not on auto), the triangle and engine battery signs flash and beep and it keeps doing that for much longer than 15 minutes at which point I switched it off not knowing if it would just keep doing this indefinitely, clearly something wrong here. What I'm not sure is whether its been doing this for the few months I have owned it or only since I had a lithium battery installed. Will start by going to dealer next time I pass, meanwhile must remember to switch fridge on/off manually

 

[Dolmen]

If it has no power source I would expect it to continue bleeping indefinately until it does have a source...... Or the battery dies .

That's what appears to be happening, I don't have a manual for the fridge so need to find one on line

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[Lenny HB]

Sounds like it's working OK.
The Lithium won't have anything to do with it Brit vans don't wire the hab battery to the fridge like German vans do.

 

[Dolmen]

Sounds like it's working OK.
The Lithium won't have anything to do with it Brit vans don't wire the hab battery to the fridge like German vans do.

Yes, everything working as it should, only thing that surprises me is that when I put it in the storage yard with gas off and no hook up, if I forget to switch the fridge off, the warning triangle, telling me there is no power input, will seemingly continue to flash presumably until I next pick it up or the batteries are flat so when not using van pretty important to remember to switch fridge to off, thought it might have shut itself down if it didn't detect any input.

 

[Hoovie]

Sounds like it's working OK.
The Lithium won't have anything to do with it Brit vans don't wire the hab battery to the fridge like German vans do.

Hey Lenny, I am going to be REALLY picky here.
for the typical British van with a Sargent electrics setup, the 'cooling' power on 12V is via the Vehicle Battery, as you quite correctly say.
However ... If it is a model with an AES function, or also one with an electronic sparked (and maybe a manual one?), the power to drive that IS from the Leisure Battery. So I guess it is possible for a fridge to drain the Leisure Battery from that load? (Not sure how many years it would take, mind )
But I am mentioning it as if you disconnect the Leisure Battery, the fridge could stop working, even if the vehicle was running (which is why with a British van that disconnects all the Hab electrics on engine start, there is still a circuit out of it that stays lives specifically for the fridge).

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[Lenny HB]

Hey Lenny, I am going to be REALLY picky here.
for the typical British van with a Sargent electrics setup, the 'cooling' power on 12V is via the Vehicle Battery, as you quite correctly say.
However ... If it is a model with an AES function, or also one with an electronic sparked (and maybe a manual one?), the power to drive that IS from the Leisure Battery. So I guess it is possible for a fridge to drain the Leisure Battery from that load? (Not sure how many years it would take, mind )
But I am mentioning it as if you disconnect the Leisure Battery, the fridge could stop working, even if the vehicle was running (which is why with a British van that disconnects all the Hab electrics on engine start, there is still a circuit out of it that stays lives specifically for the fridge).

Yep you are being picky, I think we all know the fridges with electronic control have to have a perminant low current supply from the leisure battery.

Really don't understand why Brit vans can't wire them correctly, on my van when you turn the engine off a relay changes the high power feed to the fridge from the starter battery to the leisure battery. In fact every van I have had works like that.

 

[Dolmen]

Hey Lenny, I am going to be REALLY picky here.
for the typical British van with a Sargent electrics setup, the 'cooling' power on 12V is via the Vehicle Battery, as you quite correctly say.
However ... If it is a model with an AES function, or also one with an electronic sparked (and maybe a manual one?), the power to drive that IS from the Leisure Battery. So I guess it is possible for a fridge to drain the Leisure Battery from that load? (Not sure how many years it would take, mind )
But I am mentioning it as if you disconnect the Leisure Battery, the fridge could stop working, even if the vehicle was running (which is why with a British van that disconnects all the Hab electrics on engine start, there is still a circuit out of it that stays lives specifically for the fridge).

Out of my depth now, however, when I switch the engine off with no gas connected and no ehu, the fridge warning triangle continues to flash warning me it needs a power input, until I manually switch the fridge off, it is not cooling, only a flashing light, I assumed that was being powered by the leisure battery, not sure how much power a flashing light uses, regardless I would rather it switched itself off after a set time in case I forget one time

 

[Ditcha]

Yep you are being picky, I think we all know the fridges with electronic control have to have a perminant low current supply from the leisure battery.

Really don't understand why Brit vans can't wire them correctly, on my van when you turn the engine off a relay changes the high power feed to the fridge from the starter battery to the leisure battery. In fact every van I have had works like that.

Carthago don't they wire from the starter battery not wired from leisure battery from the factory. Just a bit info for when you get your new one easy fix though.

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[scotzsue]

Think I must be odd, have never used any of ours on Auto, preferring to select source myself.


When i remember fridge sticker on steering wheel would help.

 

[Hoovie]

Out of my depth now, however, when I switch the engine off with no gas connected and no ehu, the fridge warning triangle continues to flash warning me it needs a power input, until I manually switch the fridge off, it is not cooling, only a flashing light, I assumed that was being powered by the leisure battery, not sure how much power a flashing light uses, regardless I would rather it switched itself off after a set time in case I forget one time

I doubt it will use any significant power and I wouldn't be worried about that.

I do fully get your original point and question however, and while I don't know the answer, it would make sense for a device to power off after failing to start up after a period of time (maybe 60 mins is reasonable? If it hasn't come on by then, it's not going to without some kind of manual intervention), and not stay on trying until the end of the world.

 

[Hoovie]

Think I must be odd, have never used any of ours on Auto, preferring to select source myself.


When i remember fridge sticker on steering wheel would help.

Or ... Here is a wild thought .... Try using the "auto" setting.


I know, stupid idea isn't it.

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[Lenny HB]

Carthago don't they wire from the starter battery not wired from leisure battery from the factory. Just a bit info for when you get your new one easy fix though.

There is a link on the CBE unit that you remove to power the fridge from the leisure battery.

 

[scotzsue]

Or ... Here is a wild thought .... Try using the "auto" setting.


I know, stupid idea isn't it.

Have to confess did try it on one of the vans, just didn't trust it, but it was probably better than my memory. it always chose gas even when on hook up. So that may be why i stopped using.

 

[Hoovie]

Have to confess did try it on one of the vans, just didn't trust it, but it was probably better than my memory. it always chose gas even when on hook up. So that may be why i stopped using.

there is a priority list it works to, but Gas is meant to be at the bottom I am sure? I would think it was AC, then Battery, then Gas? sounds like yours was a bit flaky?
When I got my Motorhome, it had a pretty nice (for a 3-way) Thetford AES fridge in it, and the "Auto" worked well, except the gas would not relight successfully alway, and then after I fitted a Victron Multiplus the fridge always detected AC availability due to the inverter being always available, so the "Auto" feature was not actually that useful in the end.
I swapped it out for a 240V Compressor Fridge anyway within about 6 months. I like the "auto" feature on them .... AC, AC, or AC

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[Hoovie]

There is a link on the CBE unit that you remove to power the fridge from the leisure battery.

I sometimes wonder what the electrics would be like on a motorhome if people like you, me and various others on the Forum were given a free hand

They would be either absolutely brilliant and do everything superbly, or (and I think this is more likely, especially if I had input into the design) be so complex and weird you would see owners running out their vans screaming "I can't take it anymore

 

[Ditcha]

there is a priority list it works to, but Gas is meant to be at the bottom I am sure? I would think it was AC, then Battery, then Gas? sounds like yours was a bit flaky?
When I got my Motorhome, it had a pretty nice (for a 3-way) Thetford AES fridge in it, and the "Auto" worked well, except the gas would not relight successfully alway, and then after I fitted a Victron Multiplus the fridge always detected AC availability due to the inverter being always available, so the "Auto" feature was not actually that useful in the end.
I swapped it out for a 240V Compressor Fridge anyway within about 6 months. I like the "auto" feature on them .... AC, AC, or AC

If you have the s+ connected for solar it takes 1st priority when it's activated.

 

[Hoovie]

If you have the s+ connected for solar it takes 1st priority when it's activated.

only if you have a fridge which has that (mine didn't, for example). But good info for those who do
(I suppose they should be referred to as "4-way fridges" as that is what they are )

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[denisejoe]

when you switch engine of it will just stop fridge working for 15 minutes or so you can overcome this by just switching the fridge of then on it’s a built in safety feature stops it turning to gas if your filling with fuel no one wants a naked flame in a petrol station.

 

[Ditcha]

There is a link on the CBE unit that you remove to power the fridge from the leisure battery.

If you are adding a b2b might pay to add a seperate feed from the leisure battery to the fridge using a relay or diodes as if you just link it out on the cbe the b2b will use about 15amps of the b2b output to power the fridge when driving but not a real problem depending on what size b2b you use.

 

[Brains]

Depending on age and make and model the normal default setting is:

If EHU is available the fridge will run on 240v electricity.
If no 240v electricity then the next default setting is gas.
If no 240v or gas then it will run on 12v electricity, but that tends to be only a cooler, not a fridge.

If you are driving, the fridge will keep cool on 12v
When you stop, after 15 mins, the gas will start, unless 240v available

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[Lenny HB]

If you are adding a b2b might pay to add a seperate feed from the leisure battery to the fridge using a relay or diodes as if you just link it out on the cbe the b2b will use about 15amps of the b2b output to power the fridge when driving but not a real problem depending on what size b2b you use.

They only fit a 25 amp B2B as standard.
I take it no relay like in an Elektroblock which changes the fridge between the starter & hab battery. Should be easy enough to fit a changeover relay switched by the D+.

 

[CAB96]

I think the answer to your question is.......



........ when you shut it off.

 

[Lenny HB]

If you have the s+ connected for solar it takes 1st priority when it's activated.

And how stupid is that when on EHU once the batteries are charged the fridge switches to 12v.
Dometic engineers have obviously never used a Motorhome or caravan.

I fitted a mains powered relay to turn off the S+ feed when on EHU.

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