A few questions - switches, cable size, shore power, fuses...

[Kayte]

We paid under $300 for a midsize 7.4 cubic foot 120v fridge. The 12v Victron 12/1200 inverter is more than enough power for it and extremely efficient in eco mode. We have no other major loads. No A/C or heating. All cooking and heating is via propane. If we had more room for more than the 600W of panels we have, and more space for more battery, we might consider adding a 120v heating element to the propane water heater (about $50) and adding radiant floor heat that would only run when the battery is in float, but we don’t have need for any of that. I think we could get away with a 375-500W Victron inverter for the fridge, but having the 1000W is big enough to run a full size vacuum or most power tools for short runs (I’ve tried with good results).

I forgot to include my battery in the list of electrical items I have which is a 100a 24v lithium. I don't think I mentioned 2 200w solar panels either. It's tempting to switch to 12v but since I also have the battery and those are a pricey item...... I'm wondering since my inverter is 3000w if I need another battery or if just putting inverter in standby mode will be sufficient. I can just wait and see if the one battery will be enough. I've decided to skip the shore power, I don't think I'll use it much and prefer to use solar and/or B2B. I'll wait on the B2B too and install later if the solar isn't enough. There isn't much room on van roof for another panel so B2B would help here or portable panels which would enable parking in the shade but then one has to find storage in the van for those. I have a mid-roof so not alot of garage room.
A 7.4 fridge would be great!

 

[mikefitz]

I'm wondering since my inverter is 3000w if I need another battery or if just putting inverter in standby mode will be sufficient. I can just wait and see if the one battery will be enough.

The inverter will take input power proportional to the AC loading. If you limit the AC load to a maximum of 2000 watts the single battery should be enough, ( assuming it's rated for 100 amps continious).

 

[Kayte]

Agree, it seems the smart thing initially, but the complete 12v system relies on a Chinese low cost 24 to 12 converter. If this fails you loose power to everything on the 12 volt DC circuit.
On reflection a feed at 24 volts to the fridge may be a good idea. Also consider a more up market 24 to 12 converter, more expensive but hopefully more reliable.
Need to estimate 12v power needs, rough guess with everything on you list taking power is 35 amps. Of course not everything will be on at the same time, so the average current will be lower, apart when you have heater startup I would think the typical DC current at 12v will will be less than 10 amps.

Mike

I'm assuming I need a fuse box for 24v and the only one I found is this https://a.co/d/5j8oXmY.

 

[RV8R]

I forgot to include my battery in the list of electrical items I have which is a 100a 24v lithium. I don't think I mentioned 2 200w solar panels either. It's tempting to switch to 12v but since I also have the battery and those are a pricey item...... I'm wondering since my inverter is 3000w if I need another battery or if just putting inverter in standby mode will be sufficient. I can just wait and see if the one battery will be enough. I've decided to skip the shore power, I don't think I'll use it much and prefer to use solar and/or B2B. I'll wait on the B2B too and install later if the solar isn't enough. There isn't much room on van roof for another panel so B2B would help here or portable panels which would enable parking in the shade but then one has to find storage in the van for those. I have a mid-roof so not alot of garage room.
A 7.4 fridge would be great!

Hmmmm ?

First, IIRC @Tomthumb62 setup is for a Cabin ,,, Not a Van. If Remember correctly & it is a Cabin, there are some differences in what I do for electric design ( I have both a Cabin & a Van ). Have solar @ my Cabin, but not on my Van. I suspect (as I am a Pilot & have lots of aerodynamic experience & education), that for my Van, I would spend more money on solar gasoline than alternator gasoline ,,, YMMV. My Cabin, I can install as large of an array I want & get hit with zero mpg drop ?. At my Cabin it makes sense ,,, my van ,,, not so much. Next, if I bought a 120vac cheap fridge for my Cabin, I assume my electrical energy use would double. 12vdc & 24vdc are expensive & typically way more efficient than 120vac. In my Cabin, I have an ARB 50 that I am looking to replace with a larger 12vdc fridge, but the typical energy burn a day is about 250Wh / day.

For me & my Van experience; if you are looking for self sufficiency, I would setup your inverter for “typically off” & for it to be turned on only when sporadically needed. But that is about my focus on Van electrical & might not be yours. The other way to go like “TT62” is to setup your inverter on either standby or some eco mode if it has it. Caveat, you have to research & understand the parameters which at this point I suspect you do not know (eg mechanical fridge thermostat rather than a digital thermostat).

Since you actually have 1 battery & solar already, maybe it is best to stick with the 24vdc. Please post the battery specs & solar panels specs so we can look at those. When designing your van electrical system the equipment performance specs / operating manuals are very important.

I would not purchase any more items until your design is completed & vetted. I’m sure you will get loads of advice here on the forum.?

 

[RV8R]

To review your inverter, we need to have the manual;

https://m.media-amazon.com/images/I/C1DYRyFzcbS.pdf?spm=..product_9c39d545-ef68-4b95-b785-7df359b6e068.header_1.1&spm_prev=..index.shoplazza%3A%2F%2Fapps%2Fpublic%2Fblocks%2Fproducts_grid%2F56125487021326335_2.6

Is this Your Inverter?








If so 6000W peak & 90% “max” efficiency assumed ,,, I would plan on more like 85%


You could be drawing more than 7000W @ peak & 3500W @ max continuous.

3500W/25V=140A
7000W/25V=280A


What is the 1 battery spec for max continuous amp draw?

If this is your inverter it has a “standby” current “no load” of 1.2A @ 25V = 30W @ 24hrs = 720Wh per day if “On Standby” & not used ,,, or about 200% energy use of my 12vdc ARB Fridge.

As the temperatures rise (cooling fans cost energy & efficiency decreases), it gets worse.

 

[RV8R]

These are very popular in vans;

TF130DC - 12v Refrigerator for Custom Installs - SUBSTITUTE ITEM AVAILABLE

12v Custom Semi-Truck Refrigerator for commercial trucks. Often used in Freightliner, Century, Colombia, and International 9400/9900 model trucks.

truckfridge.com

That is what we have in our van;

 

[Tomthumb62]

I'm wondering since my inverter is 3000w if I need another battery or if just putting inverter in standby mode will be sufficient.

A 3000W inverter generally will have 3x the idle draw of a 1000W one. But there are exceptions and some models can use really small amounts of power for idle draw if you enable the eco mode.

We had a Renogy 2000w inverter that used 24w idle and realized it was too much inverter for us. We “down/up graded” to a 1000w Victron. It uses 1-5w in eco mode. With a tiny system like ours (or yours), this makes a huge difference, especially during cloudy days.

Do you know what your loads are? If they’re low, then you might not need such a large inverter. Plus 3000W on 12v is on the very end of theoretical max of 12v and you’ll need massive and expensive THICK 4/0awg cables. 1500w is the most many people need, which is what a single common 120v outlet is rated to deliver. Large inverters become necessary when you have many high draw items being powered at once. List your loads and we can help you determine what size inverter you actually need.

 

[RV8R]

I'm assuming I need a fuse box for 24v and the only one I found is this https://a.co/d/5j8oXmY.

Not trying to spend your cash for you, but I like these ones;

ST Blade Fuse Block - 12 Circuits with Negative Bus and Cover - Blue Sea Systems

Compact ATO® / ATC® fuse block consolidates branch circuits and eliminates the tangle of in-line fuses for electronics and other appliances.

www.bluesea.com

 

[Kayte]

To review your inverter, we need to have the manual;

https://m.media-amazon.com/images/I/C1DYRyFzcbS.pdf?spm=..product_9c39d545-ef68-4b95-b785-7df359b6e068.header_1.1&spm_prev=..index.shoplazza%3A%2F%2Fapps%2Fpublic%2Fblocks%2Fproducts_grid%2F56125487021326335_2.6

Is this Your Inverter?






View attachment 169153

If so 6000W peak & 90% “max” efficiency assumed ,,, I would plan on more like 85%


You could be drawing more than 7000W @ peak & 3500W @ max continuous.

3500W/25V=140A
7000W/25V=280A


What is the 1 battery spec for max continuous amp draw?

If this is your inverter it has a “standby” current “no load” of 1.2A @ 25V = 30W @ 24hrs = 720Wh per day if “On Standby” & not used ,,, or about 200% energy use of my 12vdc ARB Fridge.

As the temperatures rise (cooling fans cost energy & efficiency decreases), it gets worse.

https://a.co/d/6RbaenS some differences. Mine is about 3 yrs old. (Another disadvantage to "jumping the gun", warranty expiration) Mine is pure sine, the above is modified. Maybe that's what newer ones are? The no load is different - mine 1.2a. Mine no mention of a fuse. Weight is 5.2 so definitely a different animal.
Maybe I should sell my inverter and downsize too. I'm open to that.
Is that a metal shelving unit with bins?
My fridge is a Vitrifrigo 4.7 cuft with external danfoss compressors, looks about same size as yours.

 

[Kayte]

Not trying to spend your cash for you, but I like these ones;

ST Blade Fuse Block - 12 Circuits with Negative Bus and Cover - Blue Sea Systems

Compact ATO® / ATC® fuse block consolidates branch circuits and eliminates the tangle of in-line fuses for electronics and other appliances.

www.bluesea.com

View attachment 169169

I have that one but I also need one for the 24v side so was wondering if that needs to be 24v also.

 

[Kayte]

A 3000W inverter generally will have 3x the idle draw of a 1000W one. But there are exceptions and some models can use really small amounts of power for idle draw if you enable the eco mode.

We had a Renogy 2000w inverter that used 24w idle and realized it was too much inverter for us. We “down/up graded” to a 1000w Victron. It uses 1-5w in eco mode. With a tiny system like ours (or yours), this makes a huge difference, especially during cloudy days.

Do you know what your loads are? If they’re low, then you might not need such a large inverter. Plus 3000W on 12v is on the very end of theoretical max of 12v and you’ll need massive and expensive THICK 4/0awg cables. 1500w is the most many people need, which is what a single common 120v outlet is rated to deliver. Large inverters become necessary when you have many high draw items being powered at once. List your loads and we can help you determine what size inverter you actually need.

I have a list of my loads on the 1st or 2nd page of this thread. I estimated (high end) 2000whr

 

[Kayte]

Hmmmm ?

First, IIRC @Tomthumb62 setup is for a Cabin ,,, Not a Van. If Remember correctly & it is a Cabin, there are some differences in what I do for electric design ( I have both a Cabin & a Van ). Have solar @ my Cabin, but not on my Van. I suspect (as I am a Pilot & have lots of aerodynamic experience & education), that for my Van, I would spend more money on solar gasoline than alternator gasoline ,,, YMMV. My Cabin, I can install as large of an array I want & get hit with zero mpg drop ?. At my Cabin it makes sense ,,, my van ,,, not so much. Next, if I bought a 120vac cheap fridge for my Cabin, I assume my electrical energy use would double. 12vdc & 24vdc are expensive & typically way more efficient than 120vac. In my Cabin, I have an ARB 50 that I am looking to replace with a larger 12vdc fridge, but the typical energy burn a day is about 250Wh / day.

For me & my Van experience; if you are looking for self sufficiency, I would setup your inverter for “typically off” & for it to be turned on only when sporadically needed. But that is about my focus on Van electrical & might not be yours. The other way to go like “TT62” is to setup your inverter on either standby or some eco mode if it has it. Caveat, you have to research & understand the parameters which at this point I suspect you do not know (eg mechanical fridge thermostat rather than a digital thermostat).

Since you actually have 1 battery & solar already, maybe it is best to stick with the 24vdc. Please post the battery specs & solar panels specs so we can look at those. When designing your van electrical system the equipment performance specs / operating manuals are very important.

I would not purchase any more items until your design is completed & vetted. I’m sure you will get loads of advice here on the forum.?

Initially I was hesitant to ask questions on this forum because it's "free" info and I felt "cheap" getting free info and help. I never considered all the "free" info I gladly pass on that I know a lot about. What I really appreciate about this forum besides the excellent info is the respect everyone shows for each other. So thanks to all of you and keep the info coming!

 

[RV8R]

https://a.co/d/6RbaenS some differences. Mine is about 3 yrs old. (Another disadvantage to "jumping the gun", warranty expiration) Mine is pure sine, the above is modified. Maybe that's what newer ones are? The no load is different - mine 1.2a. Mine no mention of a fuse. Weight is 5.2 so definitely a different animal.
Maybe I should sell my inverter and downsize too. I'm open to that.
Is that a metal shelving unit with bins?
My fridge is a Vitrifrigo 4.7 cuft with external danfoss compressors, looks about same size as yours.

Inverter; Ya I could not find a manual for your inverter. If you have one or a manual link posting it here can be helpful. Unless you do something like @Tomthumb62 your standyby power drain will be significant IMO fir a van. There are differences in 12vdc fridges ( or 24vdc ) & 120vac than might not meet the eye. RV fridges are designed for vehicle movement, dorm fridges are not. Appliances & Van Electrical systems “tend to change”, as I can understand you do not want to waste van space, but if you can design “the space allocation” for both standard sizes 12vdc & 120vac,

Jumping The Gun; I think we have all done that before ,,, Or there are 2 types of people ? “Those Who Jump The Gun” & “Liars”

Sorry I missed you already have the fridge & it is 24v ? ,,, So no need for a always on Inverter ?. Yes Danfoss ,,, probably the DB35 & now called Sepco.

The bins are Ikea ,,, the cabinet I built out of BB ply & aluminum angle & front to retain bins & add support to the long edge.

 

[RV8R]

I have that one but I also need one for the 24v side so was wondering if that needs to be 24v also.

Yes & Yes

That Blue Sea is 32V max ,,, So I think it works for 24v

 

[RV8R]

Initially I was hesitant to ask questions on this forum because it's "free" info and I felt "cheap" getting free info and help. I never considered all the "free" info I gladly pass on that I know a lot about. What I really appreciate about this forum besides the excellent info is the respect everyone shows for each other. So thanks to all of you and keep the info coming!

Please don’t feel cheap about asking for help, I would think the DIYers are more than happy to share things they have learned from others ,,, None of us were born with any of this knowledge, so we had to aquire it from someone.

And some of it might even be correct ?.

 

[Tomthumb62]

First, IIRC @Tomthumb62 setup is for a Cabin ,,, Not a Van. If Remember correctly & it is a Cabin, there are some differences in what I do for electric design ( I have both a Cabin & a Van ).

Our setup isn’t for a cabin but a 14’ trailer, so basically similar to a van. Photos:






Electrical stuff except the charge controller is in the tiny cubby under the 7.2cf fridge. Yes that’s a mid size fridge in a tiny 14’ trailer. We like to eat well!

Second photo L to R :
Victron 12/1200 inverter
Victron 12/30 shore charger
Powerurus 12v 200ah lifepo4
Not seen: dual USB charger for phones, 20A manual transfer switch, 20A AC breaker, 150A bus bars (advertised as 300A brass bus bars) and a mess of wires.

 

[RV8R]

Our setup isn’t for a cabin but a 14’ trailer, so basically similar to a van. Photos:

View attachment 169170

View attachment 169171


Electrical stuff except the charge controller is in the tiny cubby under the 7.2cf fridge. Yes that’s a mid size fridge in a tiny 14’ trailer. We like to eat well!

Second photo L to R :
Victron 12/1200 inverter
Victron 12/30 shore charger
Powerurus 12v 200ah lifepo4
Not seen: dual USB charger for phones, 20A manual transfer switch, 20A AC breaker, 150A bus bars (advertised as 300A brass bus bars) and a mess of wires.

Thanks for clearing that up @Tomthumb62 !!

Do you have a photo of your solar, assumed on your roof?

Van Electrical & Trailer Electrical are more similar than say a Cabin, but there are still some differences ,,, like amount or practicality of Solar Panels, Alternator Charging, & Type of Use (camping vs traveling- at least in our case), focus on weight & gas mileage).

Do you Alternator Charge? If so what does that system produce for power/energy?

 

[RV8R]

Our setup isn’t for a cabin but a 14’ trailer, so basically similar to a van. Photos:

and a mess of wires.

Well, if we are telling tales outta school ?, here is my mess of wires;



I waited 1 year for my 2021 Van, & once I got it to my driveway I had the majority built out in 6 weeks, then my regular scheduled life came into the picture & now I still have some “finishing” work to do, but here is the Utilitarian Travel Van ,,, No Solar - 250Ah AGM - Canadian Eh ??;
















The majority of my switches are right on the appliance or LED, etc. Mostly Marine grade stuff.

 

[Tomthumb62]

Thanks for clearing that up @Tomthumb62 !!

Do you have a photo of your solar, assumed on your roof?

Van Electrical & Trailer Electrical are more similar than say a Cabin, but there are still some differences ,,, like amount or practicality of Solar Panels, Alternator Charging, & Type of Use (camping vs traveling- at least in our case), focus on weight & gas mileage).

Do you Alternator Charge? If so what does that system produce for power/energy?

No photos of solar just yet. But there are 4x100W panels on the roof. And 2x100W panels in a folding ground suitcase. Wired in 6P, fuses on all except I haven’t yet gotten them on the suitcase panels.

No alternator charging. So far we haven’t needed it but in these shorter but still warm fall days solar production doesn’t always fully charge our battery via the 400w solar on the roof. I think we might have room for another 2x100w on the roof. The roof is completely bare except for a small chimney for the propane heater (about 6” diameter). I doubt you could fit 6x100w panels on a van but probably 4x100w? Most vans I see have lots of stuff on the roof like cell antennas, fans, cargo racks, etc, which cuts into space for panels.

 

[Tomthumb62]

Well, if we are telling tales outta school ?, here is my mess of wires;

View attachment 169172

I waited 1 year for my 2021 Van, & once I got it to my driveway I had the majority built out in 6 weeks, then my regular scheduled life came into the picture & now I still have some “finishing” work to do, but here is the Utilitarian Travel Van ,,, No Solar - 250Ah AGM - Canadian Eh ??;



View attachment 169173

View attachment 169174




View attachment 169175

View attachment 169176

View attachment 169177

The majority of my switches are right on the appliance or LED, etc. Mostly Marine grade stuff.

That’s not a mess of wires lol! Very clean looking, nice job!

When I remove the fridge next for some insulation upgrades, I’ll get some photos of our literal mess of wires. And some after photos once I clean them up. We spent 8 weeks of every after work minute and weekends doing major upgrades, including insulation, new flooring and completely redoing the solar system. I literally finished the electrical a couple of hours before my wife took off for a long trip and didn’t have time to tidy the wiring. But at least it all works!