question

ryang1979 avatar image
ryang1979 asked

Should I have a dedicated inverter for fridge, or just use Multiplus?

Quick questions


ive no idea about efficiency and loss etc.


have a 24/3000 inverter in the caravan. I am about to replace the fridge with a 230v (was 12v). Should I just use the Multiplus and leave in 24x7, or am I better off buying a little dedicated 250/375 phoenix inverter to do the job? I’m looking to be an efficient as possible.


also, if I installed a second inverter (the little phoenix), how will it display in ccgx as I already have the multi?


thanks

CCGX Color ControlPhoenix Inverter
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

8 Answers
matt1309 avatar image
matt1309 answered ·

Hi @ryang1979

I would go with multi.

Having 2 inverters with one gx isn't supported in the configuration you're describing. You'd end up doing some weird work with a smart shunt or equivalent monitoring the DC loads drawn from phoenix. Which isnt perfect/as flawless as just using the multiplus.

One other thing to note is make sure the fridge compressor doesn't spike usage too much for the smaller inverter to handle if you do go that route.

From a pure efficiency stand point just looking at the manuals the Multiplus ii 24/3000 states zero-load usage of 13w with max efficiency of 94% vs 6.1w with max efficiency of 89% of phoenix 24/375.

Granted if the fridge is on 24/7 at low consumption the phoenix might be more efficient as the load will probably be closer to it's max efficiency point than the multiplus however i think multiplus is the easiest route. However without testing the two side by side for your load. I dont think you'll get the perfect answer.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

blas avatar image
blas answered ·

I have installed two inverters, make sure the fridge one is big enough for my fridge 500 watt was the minimum as startup currents are what drives your inverter size. A big inverter in standby uses as much power as a fridge in a day. So depending your battery etc it could be worth it or not. For me it made sense as it makes a big difference and you save money on not buying a dc fridge. Dedicated+ small inverter is often more efficient than dc fridge due to better insulation of the fridges in Europe and it is for sure cheaper... the one that is active shows up on venus os. And both inverters and their alarms will come through..



Good luck with the build

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

sean avatar image
sean answered ·

I'd get a gas fridge ....

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Michelle Konzack avatar image
Michelle Konzack answered ·

I have the Phoenix 24/375 and it is not able to start any of my 3 Freezers or 2 Fridges (all different brands). The Freezer/Fridges need at least a Phoenix with 800VA (works only with one Freezer and one Fridge) or a 1200VA.


The starting current of the Compressors is simply to high.


Why no continue with the 12V Fridge?

I have also two Fridges Waeco/Dometic MDC110 and two Freezer Luxor using the Danfoss BD50F compressors. They all have softstart and work PERFECT with 12V DC and 24V DC. The power consumption is much lesser then the 120/230V equivalents.


Having an Inverter running for only a fridge... 500Wh a day extra!


P.S.: I am Off-the-Grid and really calculating the power consumption because I have currently not enough solarpanels which I will get in summer this year hopefully...


3 comments
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

ryang1979 avatar image ryang1979 commented ·
The old fridge is on its last legs.

a new 12v compressor in Australia is $3500. A 230v is $500.
so it just doesn’t make financial sense to stay 12v if I have a choice, and I do.


I can add 2 more solar panels to top up if needed,

0 Likes 0 ·
klim8skeptic avatar image klim8skeptic ♦ ryang1979 commented ·

@ryang1979 for a small 200l f+f, look at the Chiq 202 model.

0 Likes 0 ·
Michelle Konzack avatar image Michelle Konzack ryang1979 commented ·
@ryang1979

I can get you a new Danfoss BD35F for cheaper then the Australien 230V version speak roughly 280€+VAT or

A BD50F cost not very much more 350€+VAT.


Both controller work with 12V, 24V and Solar.


If you are interested, I can arrange it and send it to you (shipping is additional). Have only ask for the actual prices.

0 Likes 0 ·
Nev avatar image
Nev answered ·

We have a 2 door 230VAC 255l Samsung Digital Inverter fridge/freezer that has now survived 10 years of full-time travel running on the same dedicated Victron 12V 300W PSW inverter. Faultless so far.

Over here we can buy 4 similar sized Domestic fridges for the price of a quality 12V one. We would also miss the auto defrost.

We also have a switchable 1200W PSW inverter to power jug, toaster, instant pot etc.

The idle currents are 400mA vs 1000mA. I would expect that the Multiplus may draw substantially more?

That equates to an extra 15Ah daily draw if we were to use the larger inverter.

That may or may not be important for you. It is for us.



Re LPG comparison. No contest. We have saved over $10000 in LPG running costs and counting.

Enough to replace our 800W solar, 580A LiFePO4 battery, inverters, fridge, charger, solar controller, battery monitors and all associated equipment - twice!


2 comments
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

ryang1979 avatar image ryang1979 commented ·
My multi draw 20w in idle actually. so it’s a fair whack over a period of time,


we Are limited by physical size (as it’s a replacement). There is only 1 inverter compressor option which is a lg 194lt. I could fit 220l but can’t an inverter fridge in that size.



0 Likes 0 ·
phoenix avatar image phoenix ryang1979 commented ·

Is there a search mode in the multiplus as that saves a lot of energy. Equally just switch the inverter off at night. See how warm the fridge gets. If you can use node red, turn the inverter on for 30 mins every 2 hours which is how often the compressor runs on my ff.

0 Likes 0 ·
ejrossouw avatar image
ejrossouw answered ·

My approach would be to use what you have first and explore AES and search mode. Since fridges run cyclical, it should be manageable and one you have a clearer view, you can then make an informed decision and add an inverter. As for efficiency the multi is about 2% more efficient at best. With AES etc. the inverter only can potentially have a very low standby consumption. Without knowing existing consumption, battery size, you will likely be better placed to make the call.0698b28d-6ca5-49be-87d3-ae8cf7889c35.jpeg


2 comments
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

klim8skeptic avatar image klim8skeptic ♦ commented ·
@ryang1979 @ejrossouw The only gotcha with AES and search mode would be that modern fridges have electronic thermostats and are computer controlled.


Fridge might need a proper mains supply to operate correctly.


0 Likes 0 ·
Nev avatar image Nev klim8skeptic ♦ commented ·
Ours does.

The Samsung digital inverter compressor fridge electronics is always operational and requires continuous 230VAC.

Our Victron inverters will not perform in ECO mode.


An adjustable on/off timer mode may work but would probably require frequent tweaking.

It may never trigger the regular timed defrost cycles?




1 Like 1 ·
klim8skeptic avatar image
klim8skeptic answered ·

20240229-193901.jpg

5 years ac consumption with previous fridge model CTM216.

AC metered consumption includes other cooking appliances. Toaster, birko, tiny hotplate, skillet, air fryer, microwave, other stuff.

Fridge preformed better than rated specs, both energy wise, and under high ambient temps.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

ryang1979 avatar image
ryang1979 answered ·

Thanks everyone


im going to just use the multiv to begin with, and enable search mode. Search mode seems to make a lot of search regardless of the fridge in our RV setup

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.