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Here's my plan to install a 230V Mini-Split

H

HookEm

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1. The rig is a Class-C motorhome on a Sprinter VS30 chassis (Winnebago Navion), configured for 30A service.
2. Factory-installed options include:
a) 30A Diesel Generator (Cummins/Onan)​
b) (2 * 130Ah) LiFePO4/12V batteries (Lithionics)​
c) (2 * 100W) solar panels with 30A PWM controller (Zamp)​
d) 2KW Inverter/Charger (Xantrex)​
3. My plan is to:
a) Remove rooftop A/C+Heat Pump, and install 9K Btu Mini-Split with Cassette unit​
b) Remove 30A PWM controller and install MPPT controllers​
c) Remove (2 * 100W) panels from the roof, and install (4 * 425W) panels on the roof​
NOTE: The (2* 100W) panels will then be used as Portable, via existing Ground-level entry port​
d) Remove 2KW Inverter/Charger, and install 3KW Inverter/Charger (mainly to increase charging capacity)​
e) Add (4 * 130Ah) LiFePO4/12V batteries, and configure all 6 as a 24V battery bank (2S, 3P configuration)​
f) Add 230V Inverter to run Mini-Split (9A Minimum Ampacity, at 230VAC)​
g) Remove Mastervolt charger, and install 12V-24V (15A) Smart Charger (with 3-Stage charging profile)​
h) Add 24V-12V DC-DC Converters for DC loads​
​
Total Solar Capacity = 1900W (1700W on rooftop + 200W Portable)
Total House Battery Capacity = 390Ah @ 24V
The intent is to run the Min-Split 24/7, if possible, which will be a tall order in Florida... Your feedback is appreciated.
--EDIT--
BTW, the inspiration for this project was this YouTube video, which claims a 460W average consumption from a 9K Btu Mini-Split:
009 - [Redo] Solar Mini Split Air Conditioner Runs 24/7/365 Day & Night

1624417185506.png
 
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I have been thinking about what it would take to use a 230V mini split. The only problem I see .... and maybe it's a feature .... is that you would be using DC power for the mini split all the time, even when on shore power.

I have been trying to figure how to introduce a 110 to 230 V transformer and having a 110V inverter instead of a 230V inverter and use a power transfer to use shore power to the transformer when plugged in .... hope that makes some sense.
 
Bob B said:
I have been thinking about what it would take to use a 230V mini split. The only problem I see .... and maybe it's a feature .... is that you would be using DC power for the mini split all the time, even when on shore power.

I have been trying to figure how to introduce a 110 to 230 V transformer and having a 110V inverter instead of a 230V inverter and use a power transfer to use shore power to the transformer when plugged in .... hope that makes some sense.
Click to expand...
Yeap, you're right... So I also considered using a larger 120V Inverter (5KW Victron Quatro), coupled with a 120V/240V Autotransformer, but here is what turned me off from that idea:
1) The 5KW Quatro is heavy and super-expensive, and really overkill for a 30A rig
2) When running from batteries (i.e., boondocking, which is my main goal), I'd have losses from the Inverter and the Autotransformer.
 
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Yeah ..... drawbacks both ways.

If you are doing mostly boondocking, your plan may be the best.
 
I like that 230v inverter dedicated to the mini-split. Looking forward to a report on operations.

The diagram shows the batteries wired out of balance but I assume that is just to make the drawing easier.
 
time2roll said:
I like that 230v inverter dedicated to the mini-split. Looking forward to a report on operations.

The diagram shows the batteries wired out of balance but I assume that is just to make the drawing easier.
Click to expand...
By “out of balance”, I presume that you mean the lengths (routing) are not equal?
if so, yes, I just meant to show the ’electrical‘ connection.

To your point, wiring for the batteries will be a challenge:
2 of them are side-by-side under the entry steps (factory install), and othe other 4 will be in an adjacent storage compartment (most likely 2 rows of 2 side-by-side... as shown)... so I have not yet figured what the wiring will look like.
 
Wow! This is pretty much the exact concept I was going for with my soon to be delivered 2021 Winnebago View! One of the keys is the Cassette unit. Unfortunately I have not found a 120v, so 230v will have to do. I was thinking of going a little bigger on the batteries and solar if possible. Call me crazy but if my wife can't stay cool while blow drying her hair, I am a dead man! :)
 
Neon said:
Wow! This is pretty much the exact concept I was going for with my soon to be delivered 2021 Winnebago View! One of the keys is the Cassette unit. Unfortunately I have not found a 120v, so 230v will have to do. I was thinking of going a little bigger on the batteries and solar if possible. Call me crazy but if my wife can't stay cool while blow drying her hair, I am a dead man! :)
Click to expand...
 
According to my calculations, extra Solar (i.e., more than 1700W) would be more important than extra battery capacity (i.e., more than 780Ah).
(See "How much power do I need?" below).

But the challenge in a View/Navion is fitting more solar panels in the available roof-top space.
(I think 780Ah should work, but 2000 or more Watts of Solar would be ideal.... the more Solar, the better!)

How much power do I need?... It seems to me that the main questions to be answered are:
1) When the sun is *not* shining, can the battery bank sustain the overall power draw?
(Ideally, batteries could go to near near-depleted state without damage)
** The size of the battery bank can be derived from the answer to that question **

2) And when the sun is shining, can the solar panels fully recharge the battery bank, while sustaining the overall power draw?
(Worse-case: batteries start from a near-depleted state)
** The size of the solar array can be derived from the answer to that question **
 
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HookEm said:
According to my calculations, extra Solar would be more important than extra battery capacity (see "How much power do I need?" below).
The challenge is fitting solar panels in the available roof-top space... 2000 or more Watts of Solar would be ideal.

How much power do I need?... It seems to me that the main questions to be answered are:
1) When the sun is *not* shining, can the battery bank sustain the overall power draw?
(Ideally, batteries could go to near near-depleted state without damage)
** The size of the battery bank can be derived from the answer to that question **

2) And when the sun is shining, can the solar panels fully recharge the battery bank, while sustaining the overall power draw?
(Worse-case: batteries start from a near-depleted state)
** The size of the solar array can be derived from the answer to that question **
Click to expand...
I was thinking of using one or two of these for the batteries. The wheels come off to make them smaller.
https://bigbattery.com/products/24v-hsky-elite-lfp-228ah-6kwh/
 
One problem with getting a 230V inverter is that they are mostly designed to operate in Europe, with 50Hz frequency. You would also need a 50Hz air-conditioner to go with it. And, you still have a regular 120V 60Hz inverter operating right next to it.

I think a better option would be to get a split-phase 120/240V inverter that natively runs at 60Hz. That way you only have one box supplying both your 120 and 240V AC. I have this one.

Schneider Electric Conext SW4024-120/240 Inverter/Charger - RES Supply

Free Shipping! Schneider Electric Conext SW4024-120/240 Inverter/Charger, 4000W, 120/240VAC, 50/60Hz, 30A Transfer, 24VDC, 90A Charger, RNW8654024
ressupply.com ressupply.com
Another advantage of this inverter is that it already has a built-in charger function. You simply connect generator power to the ACin terminials, and the charger converts the generator's AC into battery charging DC.

So, this one box would replace three of your installation items.

BTW, Schneider also makes a 48V version of the same unit.
 
MichaelK said:
One problem with getting a 230V inverter is that they are mostly designed to operate in Europe, with 50Hz frequency. You would also need a 50Hz air-conditioner to go with it. And, you still have a regular 120V 60Hz inverter operating right next to it.

I think a better option would be to get a split-phase 120/240V inverter that natively runs at 60Hz. That way you only have one box supplying both your 120 and 240V AC. I have this one.

Schneider Electric Conext SW4024-120/240 Inverter/Charger - RES Supply

Free Shipping! Schneider Electric Conext SW4024-120/240 Inverter/Charger, 4000W, 120/240VAC, 50/60Hz, 30A Transfer, 24VDC, 90A Charger, RNW8654024
ressupply.com ressupply.com
Another advantage of this inverter is that it already has a built-in charger function. You simply connect generator power to the ACin terminials, and the charger converts the generator's AC into battery charging DC.

So, this one box would replace three of your installation items.

BTW, Schneider also makes a 48V version of the same unit.
Click to expand...
The 230V Inverter from Victron can run at 50Hz or 60Hz (configurable), so that won't be an issue.
<link> Victron Phoenix Inverter Smart

But thanks for the "Schneider" suggestion, I'll check it out,
 
Bob B said:
It will be an issue if you want to run things off that besides the mini-split.
Click to expand...
Ummh... 60Hz is not an issue, so I presume you mean 230V vs 240V?... If so, you have point!
But I don't have any plans for 240V loads... not on a 120V/30A shore-power motorhome.

Still, the Schneider unit looks very interesting... it's 20lbs lighter than the 2 Victron units on my diagram.
(Albeit, its efficiency rating seems lower in comparison)

Again, thanks for the feedback... I posted here hoping for this kind of discussion.
 
HookEm said:
Ummh... 60Hz is not an issue, so I presume you mean 230V vs 240V?... If so, you have point!
But I don't have any plans for 240V loads... not on a 120V/30A shore-power motorhome.

Still, the Schneider unit looks very interesting... it's 20lbs lighter than the 2 Victron units on my diagram.
(Albeit, its efficiency rating seems lower in comparison)

Again, thanks for the feedback... I posted here hoping for this kind of discussion.
Click to expand...
What I'm saying is if you run the Victron at 50 hz and have a mix of 50 and 60 hz appliances .... that would not be good.
 
Will your charge controller and inverter be installed inside your RV to keep the devices cool? Florida heat is over 100* so how would you cool the devices are installed outside?
 
GaRay said:
Will your charge controller and inverter be installed inside your RV to keep the devices cool? Florida heat is over 100* so how would you cool the devices are installed outside?
Click to expand...
It's a motorhome (Winnebago Navion, Sprinter VS30 chassis).
The equipment will be in a storage compartment, close to the "house" batteries.
 
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