Inverters for off road c'van

I have the same power setup Image Could Not Be Foundas MH and it works great.

I have the 210 litre Vitrifrigo and it is quiet and keeps things cold . It for me has one design fault and it is the support bracket that can break on corrigations. It then allows the door to falls off, food on the floor and honey everywhere in the hot outback Kimberley weather. You can paint in the outlines etc. Many Kedrons have made the same complaint to the point that kedron no longer use them.

I had mine SS welded (just spot welded from the factory) and has given not trouble since.

Sounds you are looking at a off road caravan design.

"Marketing-department-watts"........ love the expression!! LOL

Marketing-Department-Watts......Manufactured in China (Watts Overated)

Mine draws about 10 amps and it is on all the time, no thermostat on the 12 volt system.

Just notice the plan is for a 220litre 3 way, it'd probably draw a lot more than my 110 litre

Say the usage is 10 amps with no cycling, that's 240 amps in 24 hours, that means 2 of your planned batteries would be dead flat in 24 hours, if they were 100% charged in the first place.

A compressor unit drawing 3 amps per hour would be 72 amps in 24 hours.

That's 168 amps less in 1 day!

The compressor fridge would take 3.3 days to use the same amount of power, and in that time your solar panels would be keeping ahead of the power loss so you wouldn't normally run out of power.

210 litre Vitrifrigo fridge uses between 5 and 7 amps. Well mine does anyway. Never had a problem with keeping power upto it, even on cloudy days. See the above points though.

But Carl, thats when running it draws the ~5 amps. As it cycles on/off, it will average out around 3 amps per hour, unlike a 3 way that draws a constant ~10 amps per hour with no cycling.

Cheers

Captain

I see, my apology. Did not understand what was being said. Apparently a common fault with me, so my wife says.

Hi Evacol
re:Evakool posted:
Say the usage is 10 amps with no cycling, that's 240 amps in 24 hours, that means 2 of your planned batteries would be dead flat in 24 hours, if they were 100% charged in the first place.

A compressor unit drawing 3 amps per hour would be 72 amps in 24 hours.

That's 168 amps less in 1 day

Why would anyone with a 3way WANT TO USE it on 12v WHEN IN CAMP
A typical 3way uses little or no amphrs when on GAS.
[The intended energy source when camped!!!

I think you should not use misleading info to justify your claims for compressor fridges
Also the claim made by some that 3ways are not thermostat contolled on 12v is INCORRECT

Many Models of upright 3ways have had 12v thermo control since approx the early 90s

So Lets KEEP TO FACTS.

"T" rated 3ways correctly installed ,will perform in high temps, many have proven that.
3ways running on12v while travelling will not flatten the battery
All 3ways are thermo controlled when on 240v
Many with inadequate wiring but who have an inverter run them on 240v when travelling.
With a 3way as long as you got gas,you have a fridge
You do not have to lug a genny & possible fuel if your vehicle is diesel
Bottled gas is safer than a drum of petrol
You will get more fridge runtime from a bottle of gas than the same volume of petrol
You are not reliant on fine weather or being camped in the sun to keep the battery charged by solar panels

Re: Oldtrack123 follow-up

From my original post "happy for someone to correct me here but, I believe upwards of 6 - 8 amps 100% of the time"

First follow-up "Notso posted:
Mine draws about 10 amps and it is on all the time, no thermostat on the 12 volt system. "

Then followed by "Member - Captain (WA) posted:
But Carl, thats when running it draws the ~5 amps. As it cycles on/off, it will average out around 3 amps per hour, unlike a 3 way that draws a constant ~10 amps per hour with no cycling. "

As Evakool does not sell 3 way fridges I do not profess to know all there is to know about 3 way's, that is why I used the line in my original post to leave it open for people to correct (not attack) me.
Instead of someone advising me I was inncorrect in my statement, 2 people said they use more power than I stated and agreed they ran 100% of the time.

In the original question nothing was stated about gas, all that was mentioned was the amount of battery power avalaible and solar panels to recharge. Therefore I assumed that the question was in relation to battery power.
I agree that 3 way fridges, used in the right way, can be a very good thing on gas.
The main point I was making was that on electricity, of 2 comparable fridges, typically a 3 way fridge will use more than a compressor fridge in the same situation.

If, on the hand, Ian G in his original question had said he planned to run a T rated 3 way from battery power only when driving and gas for the rest of the time, unless 240v was avaliable, I would not have needed to say anything because he had covered the main issues with 3 way fridges and therefore a long way along to being happy with his purchase.

Yes well OldTrack,

You have made a broad statement that 12 volt fridges are thermostatically controlled.

I did say "Mine" uses 10 amps and has no thermostat.

Now if you know of one that has a thermostat I'd be interested in seeing the Specs.

Aside from that I don't see any reason to shout out people who are after all just having a bit of a discussion. If anyone wants Technical info on anything rather than general knowledge gained over a number of years doing what we do then they will obviously ask the experts, like you!

My apologies for lack of detail in original post. Put it down to inexperience by a first time user.

Hi Evacool

I apologise if you took my post as a personal attack.
My concern was that the OP was getting a pretty one sided answer to his question
I believed he needed both options explained so he could make a sound decision on what wouldbest suit his needs
For him to do that, he needed facts on both types
Peter

Hi Notso
Re:Now if you know of one that has a thermostat I'd be interested in seeing the Specs."
Well , I would suggest you research the following Dometic series for a start.

RM : 2310 ,2410,2510 ,2510 ,2610, 2810 2453 ,2553 ,76x1, 78x1 ,76x5 ,78x5, for a start

Peter

Hi Notso

Perhaps YOU should reread my post
I did not make a broad statement that ,YOUR quote"You have made a broad statement that 12 volt fridges are thermostatically controlled. "

THIS is what I said:
Also the claim made by some that 3ways are not thermostat controlled on 12v is INCORRECT

Many Models of upright 3ways have had 12v thermo control since approx the early 90s

So Lets KEEP TO FACTS.
Peter

Hi All
Re thermo control on 12v

It seems many who do have thermo control on 12v are not aware of it.

If anyone would like to know if theirs is ,just post brand & model number & I will try to confirm

Peter

If as you say some of em have thermostatically controlled 12 volt I reckon it'd be a moot point anyhow as none of em are efficient enough on 12 volt to get down to a reasonable temp for the thermostat to kick in, so it'd still be drawing the 10 or 12 amps full time anyhow.

Hi Notso

Since the elements wattages on 12v & 240v is usually very close to being the same, why should it not be just as efficient as on 240v??

Peter

Yeah I suppose that seems to be the case but ask anyone who has one in the real world and they will barely keep the fridge cool when travelling. Even though mine has 12.8 volts at the fridge when on 12 volts it is just not up to the task.

Works best on Gas and next best on 240volts. lousy on 12 volts, but after all the only reason you would use 12 volts is whilst travelling anyhow, the fridge isn't getting opened all the time so it just helps to keep things cool till we get to the next stop.

Hi Notso
Since we seem to have come to some agreement , could I ask what model fridge you have???
Note that in the above I said " is usually very close to being the same "
Perhaps your's is not in that category

Peter

RM 4401 or 4400

I have the circuit diagrams and there is no thermostat in the 12 volt circuit.

The 240 volt element is 125 watts and the 12 volt is 120.

Contrary to a lot of posts I have never been unhappy with the performance of the fridge, even up in the Kimberleys in 45 + temps it has always worked fine on Gas and 240volt.

G'day again Captain. You have got me thinking again (always a dangerous thing). Should the dc/dc charger be located b/w the starting battery and the aux located on the other side of the engine bay (bearing in mind that there is already an isolator to prevent the main being flattened by the aux)?. I assume this would then mean that I would be expecting the dc/dc charger to maintain full top up charge to 4 x batteries @ 460 a/h, ie 1 x100 a/h aux and 3 x 120 a/h in the c/van some 5-6 metres away. If this assumption is correct, would it be beyond the capabilities of the Ctec D250s dual?. However, it would have the advantage of a) I could use my portable 80w solar panel to keep the aux battery charged when not hooked up to the c'van and b) being able to charge the aux when hooked up to the c'van by way of the solar or mains setup in the c'van ( the D250s' return blocking mechanism would no longer be a concern as it would be at the other end of the batteries b/w aux and starting battery). Does this make sense or do I misunderstand the way batteries/electrics operate?. Any comments/suggestions would be welcomed and appreciated.

Oops! The above may make more sense if you read my follow up (id706638 of 9/11) which I incorrectly posted under my own reply 6 of 8 below.

Hi Ian,

Any dc-dc charger should be placed as close as practical to the battery being charged, otherwise you will be back to voltage losses due to cable runs. IMHO I would use the solar and 240V charger to ensure full charging of the van batteries for the majority of the time and top up via the vehicle alternator while travelling (anderson plug connection). I would locate the dc-dc charger after the aux battery isolator and keep the calcium aux battery fully charged by it. The main battery will be kept charged by the vehicle alternator.

If you use the dc-dc charger for the van batteries (ie.place it in the van), while it will keep the van charged, you have nothing to keep the calcium battery fully charged. While you could get a second dc-dc charger for the van, the odd time you are traveling and cannot fully charge it via solar or 240V within a few days will make no material difference to battery life and IMHO is not cost effective.

Cheers

Captain

Thanks Captain. I will be installing a dc/dc charger b/w tow vehicle and c/van battery bank (as close to batteries as possible) The setup I have in mind would, after the c'van batteries are fully charged, allow for any excess charge to go back to the aux battery in tow vehicle. This would occur using solar (when camping) or mains (c'van park or generator). The dc/dc charger may have a blocking mechanism to prevent the current flowing back but I'm sure this could be overcome. Obviously the tow vehicle would need to be hooked up to the c'van on the occasions that I want this to work (to ensure 40l Engel in vehicle keeps working). Again, any comments/suggestions would be welcomed.

Hi
This is the area that is incorrect:

"quote}Safety Issues

Electrocution
The 240 volts from an Inverter can kill you instantly, just like the 240 volt at home, so you need to take precautions. All modern houses have a Safety Switch (or Earth Leakage Circuit Breaker - ELCB or Residual Current Device - RCD) to cut off power quickly if someone touches the 240 volt while earthed - but many Inverters do NOT have them. Safety Switches will only protect against electrocution to earth if you connect the Earth Terminal on the Inverter to an earthing rod that has a good earth connection - a rod into dry sand is useless.


TIP Always use a Safety Switch at the Inverter if one isn’t built in - it’s very cheap protection against a fatality. [quote]