Electrical Not all van fridge electrical connections are the same

[mikerezny]

Thanks Mike @mikerezny for your comments. I will answer/comment on each point you raised:
He has NO solar on roof top or any other solar panel/s. In fact, van is not set up for any solar!!
Yes, while he may be driving a fair bit during the day, his Playdoh (2008 model common rail) has one of those "smart" alternators which would certainly not get his 120ah AGM up to full storage capacity. Refer one of my earlier posts regarding this. In fact, he has remarked that the alternator will not (or takes a very long time?!) to bring tug battery from low to full charge potential. He puts tug battery on a smart charger sometimes and it takes overnight to get to "float" position! I doubt that there would be 13.8 volts at the van battery terminals anyway, which is NOT enough to charge van battery , even if tug battery has been charged sufficiently and before it switches to "free running". Might get him to put smart charger onto van battery when at home and more often??
As far as temperature in fridge is concerned, his fridge was the one I posted a story about some time ago regarding removal, clean, block holes, and other various repairs/baffle fitting etc. Although he now admits more efficient, I do not think he is aware of temp situation too much.
He is on his third van battery in 10 years, so your calculations are pretty close to the mark. Not helped by van sitting for up to 3 months at a time and no battery charging occurring regularly.
His fridge has no thermostatic control when on 12 volts, only on 240 volts AC.
I doubt he is likely to spend money on a solar set up as he is pretty ignorant of solar charging, but I will mention it to him. He frowns at wife and I going "off grid" - never free camps!. The idea of an extra battery in parallel would seem to be an easy fix, but once again he has his own ideas, so I might just listen and let him run with it!! However, he may want me to assist/do? the change over to what he wants after he gets a quote from a "sparkie" to do the job.
Sigh!! Some people do not want to change and to each his own...... until help is needed! Thanks

Yep, we all have different ways we enjoy camping and likewise different priorities on how we implement solutions to issues based on our expertise and/or previous experiences. It is unlikely there will ever be a one size fits all. As long as you can make him aware of the possible solutions, each with their pros and cons, he will be in a much better position to make an informed decision and to understand how to manage the solution he prefers.
In the end, he has to be comfortable with any solution he adapts.

Off topic, but I have one great neighbour (retired fitter and turner) and another who is a good friend (electronics engineer), both with batteries in vehicles that got little or no use. Short of beating them around the head with a battery charger I could get neither to keep the batteries topped up so they would be able to start the car when needed. Wind the clock forward, and both have stuffed batteries. I even offered to take the batteries out, bring them home and keep them topped up every couple of months. Neither could be bothered. In one case, two 150Ah Calcium batteries (2 year old mandatory replacements from a fork-lift) just sat in the corner for two years until they were dead. The battery charger he owned was less than 2m from the batteries!

cheers
Mike

 

[Drover]

So what's his problem with just using gas when he pulls up ??? I met a fella at camp once who never used 12v, those of us around the happy hour table our jaws dropped when he said he runs his on gas in camp, on the road and the warnings were histeric BS, made sure I stayed away from him on the road.........

 

[Boots in Action]

Yep, we all have different ways we enjoy camping and likewise different priorities on how we implement solutions to issues based on our expertise and/or previous experiences. It is unlikely there will ever be a one size fits all. As long as you can make him aware of the possible solutions, each with their pros and cons, he will be in a much better position to make an informed decision and to understand how to manage the solution he prefers.
In the end, he has to be comfortable with any solution he adapts.

Off topic, but I have one great neighbour (retired fitter and turner) and another who is a good friend (electronics engineer), both with batteries in vehicles that got little or no use. Short of beating them around the head with a battery charger I could get neither to keep the batteries topped up so they would be able to start the car when needed. Wind the clock forward, and both have stuffed batteries. I even offered to take the batteries out, bring them home and keep them topped up every couple of months. Neither could be bothered. In one case, two 150Ah Calcium batteries (2 year old mandatory replacements from a fork-lift) just sat in the corner for two years until they were dead. The battery charger he owned was less than 2m from the batteries!

cheers
Mike

Yes, so sad @mikerezny !! But one has to have the MOTIVATION to do things or get things done. You cannot help those who don't want to be helped!!

Also off topic, discovered that my Thetford 3 way fridge has a 180w element for 240 volt operation, but only a 144w element for 12 volt operation. If I ever get fridge out, I have a spare 175 watt I recovered from a non functioning/non working Camp Smart 38 L fridge. Might help my fridge work better on 12 volts from Tug?

 

[Boots in Action]

So what's his problem with just using gas when he pulls up ??? I met a fella at camp once who never used 12v, those of us around the happy hour table our jaws dropped when he said he runs his on gas in camp, on the road and the warnings were histeric BS, made sure I stayed away from him on the road.........

Some Mothers do have 'em @Drover !! Similar case!! This friend has only used the 240v system for cooking and never used the gas. Tight as... !! His wife's response : " Why use my gas when I can use the 240volt power provided in caravan park site, for which I am already paying"?? In fact, he still has the original 4kg gas bottles that came with the Eco Tourer and has never had the need to use/ refill them. Would not be able to do so now as out of date. So I will let him tread his own path!!
Another interesting point with his van is that the lights inside are 12 volts alright, but AC current!! Cannot replace with LEDs because 50hz cycling causes lights to flicker. Funny sort of electrical set up and wiring! 240 volt to 12 volt step down transformer only has rectified DC circuit to charge battery. Charging output not known. Had one of those to work on @Drover ? Not MY type of van but they are happy with it. Still a good friend though.

 

[mikerezny]

Yes, so sad @mikerezny !! But one has to have the MOTIVATION to do things or get things done. You cannot help those who don't want to be helped!!

Also off topic, discovered that my Thetford 3 way fridge has a 180w element for 240 volt operation, but only a 144w element for 12 volt operation. If I ever get fridge out, I have a spare 175 watt I recovered from a non functioning/non working Camp Smart 38 L fridge. Might help my fridge work better on 12 volts from Tug?

Hi,
That is useful information. I am always preaching that a Dometic late model RM2350 90l fridge with a 175W 240V element and a 175W 12V element will perform equally well on either 240V or 12V. So it is good to have an example of a fridge that would not perform as well on 12V as on 240V. What model Thetford is it?
I can then quote two specific fridges: one that will perform equally well on 240V and 12V (if wired up correctly) and another where the performance on 12V will differ from that on 240V. Some larger Dometic 3-ways also have a higher wattage element for 240V.

Can you not change the element without removing the fridge? I am fairly sure it can be done on my Dometic. I have seen some YouTube videos showing how it is done. You might need to get hold of a circuit diagram of the to see if there are any hidden inline fuses that might need replacing to cope with the higher current.

cheers
Mike

 

[Boots in Action]

Hi,
That is useful information. I am always preaching that a Dometic late model RM2350 90l fridge with a 175W 240V element and a 175W 12V element will perform equally well on either 240V or 12V. So it is good to have an example of a fridge that would not perform as well on 12V as on 240V. What model Thetford is it?
I can then quote two specific fridges: one that will perform equally well on 240V and 12V (if wired up correctly) and another where the performance on 12V will differ from that on 240V. Some larger Dometic 3-ways also have a higher wattage element for 240V.

Can you not change the element without removing the fridge? I am fairly sure it can be done on my Dometic. I have seen some YouTube videos showing how it is done. You might need to get hold of a circuit diagram of the to see if there are any hidden inline fuses that might need replacing to cope with the higher current.

cheers
Mike

Hi @mikerezny , did a check on the heating element 12 volt type for my Thetford 3 way Model N304-3. It appears that this model was originally fitted with the 12A 144w heating element and that part is in the list for spare parts for this model. However, on another website for Thetford fridge spare parts, there is another heating element listed as suitable for the same model - 14 volt 196W. That is a 36% increase in heating capacity on what is currently fitted. The big question now is:- Is it worth the money to upgrade for more heating power? Will the additional heating result in better refrigerator cooling whilst connected to my tug? And is the hassle of removing old 144w element and fitting the (later model?) 196w element worth it? There does not seem to be any problem electrically as the later model element has MUCH THICKER wiring to the element than the thin type now in place and a 20A fuse protects this circuit. I can remember @Drover mentioning this problem on an earlier post that the wires to the element from the main wiring junction point were often very hot, and in most cases too thin to carry the current for long periods. I guess it might be a bit of over kill, but as someone said on this forum, absorption fridges operating on 12 - 14 volts need all the help they can get.
The link for the new part is below. What do you think? Cost is irrelevant if it is better and time is my own, so ........?

https://www.ebay.com.au/itm/Thetfor...b1b64ac:g:Iu4AAOSw0vJb3QXJ:rk:1:pf:0#rpdCntId

 

[mikerezny]

Hi @mikerezny , did a check on the heating element 12 volt type for my Thetford 3 way Model N304-3. It appears that this model was originally fitted with the 12A 144w heating element and that part is in the list for spare parts for this model. However, on another website for Thetford fridge spare parts, there is another heating element listed as suitable for the same model - 14 volt 196W. That is a 36% increase in heating capacity on what is currently fitted. The big question now is:- Is it worth the money to upgrade for more heating power? Will the additional heating result in better refrigerator cooling whilst connected to my tug? And is the hassle of removing old 144w element and fitting the (later model?) 196w element worth it? There does not seem to be any problem electrically as the later model element has MUCH THICKER wiring to the element than the thin type now in place and a 20A fuse protects this circuit. I can remember @Drover mentioning this problem on an earlier post that the wires to the element from the main wiring junction point were often very hot, and in most cases too thin to carry the current for long periods. I guess it might be a bit of over kill, but as someone said on this forum, absorption fridges operating on 12 - 14 volts need all the help they can get.
The link for the new part is below. What do you think? Cost is irrelevant if it is better and time is my own, so ........?

https://www.ebay.com.au/itm/Thetfor...b1b64ac:g:Iu4AAOSw0vJb3QXJ:rk:1:pf:0#rpdCntId

Hi @Boots in Action,
If you do the maths, the 14V 196W element would have a resistance of 1 Ohm. If we assume that the spare 175W element you have is rated at 12V, it has a resistance of 0.822 Ohm. If that is the case, the 175W element will produce 238W when connected to 14V. So, the old 175W element you have will produce more heat at 14V than the advertised 196W element.

Time to get your multimeter out and measure the resistance of the element currently in your fridge and your spare 175W element before parting your hard-earned cash that could be better spent buying us drinks when we next get together!

I don't agree with the statement above about 3-ways on 12V needing all the help they can get. IF they are wired correctly AND they have the same wattage element for both 12V and 240V they don't need any more help than they would need when connected to 240V. They will have identical performance!
If they suffer on 12V comapred to 240V then EITHER they are not getting sufficient voltage to the element OR the 12V element is a lower wattage than the 240V element. Note, I have deliberately avoided completely ANY comparison to the relative fridge performance when running on gas.

A late model Dometic RM 2350 90l fridge with 12V wired correctly will work equally well on either 12V or 240V since both elements are rated at 175W.

cheers
Mike

 

[Boots in Action]

Hi @Boots in Action,
If you do the maths, the 14V 196W element would have a resistance of 1 Ohm. If we assume that the spare 175W element you have is rated at 12V, it has a resistance of 0.822 Ohm. If that is the case, the 175W element will produce 238W when connected to 14V. So, the old 175W element you have will produce more heat at 14V than the advertised 196W element.

Time to get your multimeter out and measure the resistance of the element currently in your fridge and your spare 175W element before parting your hard-earned cash that could be better spent buying us drinks when we next get together!

I don't agree with the statement above about 3-ways on 12V needing all the help they can get. IF they are wired correctly AND they have the same wattage element for both 12V and 240V they don't need any more help than they would need when connected to 240V. They will have identical performance!
If they suffer on 12V comapred to 240V then EITHER they are not getting sufficient voltage to the element OR the 12V element is a lower wattage than the 240V element. Note, I have deliberately avoided completely ANY comparison to the relative fridge performance when running on gas.

A late model Dometic RM 2350 90l fridge with 12V wired correctly will work equally well on either 12V or 240V since both elements are rated at 175W.

cheers
Mike

Hi Mike @mikerezny , some more news for you. You saved me about $100.00 and some unnecessary time too. Had a good look through the Thetford instruction and user manual and discovered that the heating element in my Thetford fridge (N304-3) is rated at 12 amps at 12 volts (144 watts) and 14 amps at 14 volts (196 watts). So the one on Ebay is rated at the 14 volt rate as against the wattage listed inside the fridge itself and different again in Ownwer's book!! Correct rating on plate inside fridge for 240 volt operation was 180 watts which was in accord with reading of 0.75A at 240 volts in mamual. Yet all come to the same result. So no changes to be made and more money for your cider and wine for Lady when we get together again.
The bad news is that the element from the discarded 38 litre fridge is only 75 watts and NOT 175 as I hoped for. Rough multi meter reading was approx1.9 ohms confirmed this.

 

[Fallen]

Not to hijack this thread, but what is the standard Jaco Expanda wiring setup out of the factory regarding running the fridge from the tug? Or do they only come wired with a standard 7 plug setup and you'd have to wire a 12 pin setup or Anderson setup yourself post delivery? Specifically asking re a circa 2012 Expanda.

 

[Boots in Action]

Not to hijack this thread, but what is the standard Jaco Expanda wiring setup out of the factory regarding running the fridge from the tug? Or do they only come wired with a standard 7 plug setup and you'd have to wire a 12 pin setup or Anderson setup yourself post delivery? Specifically asking re a circa 2012 Expanda.

Hi there @Fallen and welcome to the forum. Lots of members on here to help you, and you are NOT hijacking this thread.
This particular question I cannot give a proper answer as I have the "smaller Jayco Penguin" not an Expanda! However, when I took possession of my Jayco 2013 van (pre-owned), it did not appear to have any modifications as the previous owners (an elderly couple from Perth) had just driven it over to Brisbane. My van was wired with 7 pin flat plug to operate van indicator, width and stop/park lights also electric brakes and a common earth return for all these. It also had an Anderson plug for tug consisting of two heavy wires going direct to fridge terminals and a smaller wire off the positive line which went to the Setec Controller to charge van battery. I believe that the Expandas are wired similarly, but there are plenty of members with Expandas to provide the correct information. Some may say that a 12 pin plug (which has 5 heavier connectors for high current devices plus the usual 7 standard pins) is satisfactory, but IMHO , it is much better to have an separate Anderson plug to provide the heavy current from tug to van. It is also easier to connect the heavier cable to an Anderson plug than it is to a 12 pin plug.
I have changed the van connector to a 12 pin plug (kept the Anderson plug) so that I could provide a heavier earth return for ALL the circuits including the Setec charger. Note that the fridge has its own separate earth return as one of the heavy wires to tug from van provides this connection. Hope this helps and there will be plenty of others to put in their advices too!! Good luck.

 

[Boots in Action]

Hi there @Fallen and welcome to the forum. Lots of members on here to help you, and you are NOT hijacking this thread.
This particular question I cannot give a proper answer as I have the "smaller Jayco Penguin" not an Expanda! However, when I took possession of my Jayco 2013 van (pre-owned), it did not appear to have any modifications as the previous owners (an elderly couple from Perth) had just driven it over to Brisbane. My van was wired with 7 pin flat plug to operate van indicator, width and stop/park lights also electric brakes and a common earth return for all these. It also had an Anderson plug for tug consisting of two heavy wires going direct to fridge terminals and a smaller wire off the positive line which went to the Setec Controller to charge van battery. I believe that the Expandas are wired similarly, but there are plenty of members with Expandas to provide the correct information. Some may say that a 12 pin plug (which has 5 heavier connectors for high current devices plus the usual 7 standard pins) is satisfactory, but IMHO , it is much better to have an separate Anderson plug to provide the heavy current from tug to van. It is also easier to connect the heavier cable to an Anderson plug than it is to a 12 pin plug.
I have changed the van connector to a 12 pin plug (kept the Anderson plug) so that I could provide a heavier earth return for ALL the circuits including the Setec charger. Note that the fridge has its own separate earth return as one of the heavy wires to tug from van provides this connection. Hope this helps and there will be plenty of others to put in their advices too!! Good luck.

Hi there @Wombat6 , this may help you in addition to what you have already seen on the other post.

 

[jazzeddie1234]

On my fridge I have a D+ sense wire that tells the fridge to use 12V. Jayco simply joins this to the 12v line. I tried several relay types in the tug but opted for, in my case, a really simple solution. I removed all relays and direct connected the crank battery to the fridge. I then found the ignition wire (that would normally operate a relay) and ran this all the way to the D+ through a spare on the 12 pin plug. Now the fridge goes to 12v with engine running and there is no voltage loss from a relay and my dc dc sticks to keeping my second battery charged. I reconnect the D+ to the 12v with a switch behind the fridge if I have to tow with a standard 12pin

 

[Drover]

I just connected the D+ wire to the 12v supply from tug to fridge at back of fridge, (mine runs direct from tug battery via an Anderson) a relay under bonnet working off a ignition circuit cuts power to fridge when engine stopped. Don't like having extra cable runs or switches.

 

[BJM]

One thing that is not mentioned ,is the fridge properly insulated.?The Dometic 2350 in my Discovery Offroad had no insulation around fridge at all.Not unusual.Packed roof insulation top ,sides etc made a large improvement in keeping the fridge cold ,combined with fitting twin fans in the outlet vent.

 

[jazzeddie1234]

My starcraft fridge is somewhat insulated but the cabinet walls between the fridge and external wall get really warm and heat up my cupboards. I have some car insulation (self adhesive 6mm foam with aluminium foil surface) that I may use to line the exposed walls next time the fridge is out... and fit something to close the gap between the cooling fins and external wall (as required in the install manual but ignored by jayco)

 

[jazzeddie1234]

Drover my setup started that way but I needed 2 relays - between crank and 2nd (in my ute tray) batt and between tray to 12 pin. Too much loss and complexity for me. Now I have direct crank to 12 pin + anderson, and tray to 2nd anderson (dcdc from crank to tray batt). The van has an anderson hooked directly to the van battery (not the fridge as most do). This gets me a really flexible set of freecamp options: standard jayco, charge van direct from alternator or dcdc, charge tray or crank from van solar. Next plan is to increase tray batteries to 2 x 100ah so extra weight is in ute and not van

 

[Drover]

Yours sounds like a complicated set up to me @jazzeddie1234 , my only power from tug to van is the fridge anderson, no 12v to van for charging, not needed at all and my tug aux battery is charged from a solar panel on the utes roof and runs an engel, original plan was to fit a Cetek D250 to charge aux but while it could be handy at times not worth the expense, portable solar can be plugged into ute or van if required, we only free camp and it all works well and we stop for days or weeks at a time, solar charges the van all the time, ....................... once in the last few years I did need to run the genny after days of clouds, did the washing at the same time and charged all phones and laptops , Genny noise drowned out by skiers, so win, win all round......

But putting your storage in the ute, wouldn't that mean it has to connected to van all the time ???? ................ When I have my solar plugged into ute I always have the lead where I trip over it so I don't drive off with it connected................I have thought of plugging my big lead into ute aux to give van more juice but its a Wet battery so wouldn't be happy with my 2 Gelly Babies in van.....since it lives under the tray no need for expensive GEL/AGM it can vent away happily, more amp for $$ that way.......................be a different story if I couldn't put solar on ute roof though...........trouble with batteries no matter where they go they are damn heavy, my ute doesn't need another 35kg added to it I know that, steel tray needs to be ditched for an alloy one I think.........................off topic.......

 

[Drover]

In regard to your walls getting hot, a small section at side can get warm but if whole side and top of cupboard is getting hot then the fridge isn't fitted correctly, the outer wall will get hot that's understandable, a fan sucking the air out the top vent gets rid if most of that heat but at back of fridge the gap between fridge and cupboard walls should be sealed along with the top including cable runs.........

 

[jazzeddie1234]

My first vist to the weigh bridge had the van heavier than the ute which I hate so moved things around including the van spare to get the ute up and van down. I still have about 150kgs spare in the ute with people onboard and van attached. The ute has some solar but is always connected to the van by a heavy duty anderson cable (when parked that is...) and I can always move the battery later. like you i prefer old school batteries in the ute tray, currently dual purpose marine, and can live with them paired to the van agm for now

 

[jazzeddie1234]

I think it is the small strip at the rear of the fridge (about 300mm) on each side. I got jayco to remove the fridge and silicon all the corners.. under warranty!... to keep dust out. But the rear gap from fins to wall is much bigger than spec so the fridge has to work harder. At least they put in the baffle to direct air out of the top vent