Your correct about length. But even at full load a 3000 watt inverter will not get to 260 amps.
Greg
Is The Inverter Charger Necessary On A RV
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Greg
John Frum
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Please refer to the link below.
page 8
See the table entry for the evo3012 which is a direct competitor of the multiplus.
Even a high frequency inverter can theoretically hit 275 amps service current at full load.
With standard headroom of 125% that is 367 amps fault current.
3000 ac watts / .85 conversion factor / 12 volts low cutoff = ~294 dc amps
~294 dc amps / .8 fuse headroom = ~368 fuse amps
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True enough, but now look at realty. Those numbers are good for continue service. How long are you really going to draw 100% for more than a few minutes? All I have is 2 AC and a micro wave and all three would never be on at the same time. It's great info to have but in and RV it just isn't going to happen.
Greg
John Frum
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As a matter of policy I design for full load through the inverter and ignore the pure dc loads unless they are significant.
You said a 3000 watt inverter could not pull 260 amps and I've shown that they can.
John Frum
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I want the fuse to blow before the wire insulation melts or catches fire and I don't want nuisance trips so I go with the numbers.
RF_Burns
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New here, so apologies if I step on any toes.
I have a Samlex EVO-1212 inverter/charger/transfer switch with solar input (150W panel) in my motorhome since 2018 and except for the weight, I like it a lot. I had a mobile communications business for 40 years and used a lot of Samlex equipment with near zero failures. I can't say that for the high end public safety equipment we maintained.
I prefer higher voltage configurations for lower current if that is an option.
I have a Samlex EVO-1212 inverter/charger/transfer switch with solar input (150W panel) in my motorhome since 2018 and except for the weight, I like it a lot. I had a mobile communications business for 40 years and used a lot of Samlex equipment with near zero failures. I can't say that for the high end public safety equipment we maintained.
I prefer higher voltage configurations for lower current if that is an option.
Zwy
Solar Wizard
I actually hit upon a better idea the other day. I was planning on removing the AC to DC converter but will leave it in place and install a switch to turn it on/off. The only load for the converter will be the truck camper jacks. I'll power up the converter thru the 3000w inverter when needed.
moonlitsouls
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pretty terrible amazon reviews
John Frum
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Then don't use that one.
There are plenty of ul-458 listed inverters that will work fine.
I'm didn't read the review to see what people didn't like about that particular model but aims has a pretty good reputation for making value stuff that works.
Can you characterize the major objections?
Actually why are we talking about this model, did someone recommend it?
DerpsyDoodler
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When you store your lifepo4 batteries for long periods, they should not be charged more than 50% capacity.So I was somewhat on the right track, the Renogy 3000 Inverter / charger is the unit I was looking at:
3000W 12V Pure Sine Wave Inverter Charger w/ LCD Display
Renogy 3000W pure sine wave inverter charger not only acts as a DC to AC converter but also charge and maintain a battery bank. Compatible with various batteries.ca.renogy.com
That being said, this is a 3000W unit, I couldn't tell if this unit is low or high frequency (how can you tell?). According to SmoothJoe I'd be pushing it at 12V.
What you're saying is my batteries may not support being joined serially. This is news to me as I am used to "dumb" led acid batteries. I purchased the batteries on Amazon: https://www.amazon.ca/gp/product/B08KZQBMSL/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
There is limited information on the capability...
As far as the batteries running down, I was more worried about the opposite effect. There is plenty of sun here, so can the batteries get damaged if they're constantly being charged and full or is a good mppt controller completely mitigating that aspect. Otherwise, I can put them on a maintainer over the winter for storage while not connected to the solar system.
AfterShock
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I've been going back and forth between the 24V and 12V Victron 3000 for a while now, mainly because I ordered 2 panels at 425W each, which brings my need for a Victron 150/60 MPPT at 12V rather than a 100/30 MPPT which is half the price.
I keep thinking that relying on the extra components of either having another independent 12V battery or a buck converter adds to the likelihood of a failure somewhere.
The only buck controller that I could find in Canada that isn't a no-name brand is the Victron Orion, which gives me 840V continuous. Is that enough for a 29' RV? I could not find much information online.
Also, everyone seems to be putting an inline fuse between the batteries and the inverter. I would much rather buy a circuit breaker if I can but I am having a hard time finding something for a 4/0 AWG cable that doesn't need to be inside a breaker box. Any ideas? Also should I go with exactly 3000W with a 250A breaker or slightly above at 300A
I keep thinking that relying on the extra components of either having another independent 12V battery or a buck converter adds to the likelihood of a failure somewhere.
The only buck controller that I could find in Canada that isn't a no-name brand is the Victron Orion, which gives me 840V continuous. Is that enough for a 29' RV? I could not find much information online.
Also, everyone seems to be putting an inline fuse between the batteries and the inverter. I would much rather buy a circuit breaker if I can but I am having a hard time finding something for a 4/0 AWG cable that doesn't need to be inside a breaker box. Any ideas? Also should I go with exactly 3000W with a 250A breaker or slightly above at 300A
Whinny
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If you want a breaker look at Midnite Solar/Carling.
I would not use a breaker, it's not something that should ever trip or blow except in a catastrophic failure. Using a 3 position battery switch modified with pre-charge and a class "T"is better IMHO...
This is from the Victron 12-3000va manual....bigger is always better though.
Recommended DC fuse400A Recommended cross section (per + and - connection terminal) 2x AWG 1/0
Make sure you are comparing correct numbers for inverter capacity some are rated in VA some in watts
I would still stick with 12v-but thats just me....
I would not use a breaker, it's not something that should ever trip or blow except in a catastrophic failure. Using a 3 position battery switch modified with pre-charge and a class "T"is better IMHO...
This is from the Victron 12-3000va manual....bigger is always better though.
Recommended DC fuse400A Recommended cross section (per + and - connection terminal) 2x AWG 1/0
Make sure you are comparing correct numbers for inverter capacity some are rated in VA some in watts
I would still stick with 12v-but thats just me....
John Frum
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840V makes no sense.
What amp rating is the ac2dc converter that came with the RV.
If you are not adding any dc loads that is the rating that you need.
Most RV's will run with the battery disconnected.
I suggest that for a test you disconnect the battery and try the big draw loads to see if they run ok off the ac2dc converter.
If they do then a quality dc2dc converter of the same rating should work.
Thermal breakers for the amperage you need at 12 volts is a non starter.
You may be able to find a magnetic breaker but I expect it will be expensive.
As I stated above with math to back it it up.
You need 2 current paths each with over-current protection to handle 250amps.
I guess you could do 1 current path but the wire to do that is huge and requires special tools.
This is one of the tools
This is why we urged you to consider 24 volts nominal.
You need 2x 250 amp magnetic breakers with cable to handle the fault current.
Have a look at my math throughout this thread.
Class t fuses are the best option.
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Zwy
Solar Wizard
If you start adding more panels, you will wish you went with a 24v system.........
I have a 3000w inverter and this is why I went with 24v. Makes life easier and components easier to find to hook it up including ANL fuses. You can get a 300A ANL fuse and holder, that's the max I see. It would get you there on 12v provided there isn't a large surge. Do you really think you will run the inverter at max 3000w? I plan on maybe 2000w max and I'm on 24v. On 24v, I can get by with 150A ANL fuse. I was able to run much smaller cable than 4/0 also. Makes life so much easier.
Would I use a breaker for this purpose? No.
The buck converter is not that big of a deal. Maybe you should audit what your current usage is on 12v accessories? Have you reduced load already such as led lighting? And many things can be retrofitted to run on 24v without the buck converter.
AfterShock
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I ended going with a web store wiring diagram...
Seems ideal as all the components are listed and I can still upgrade later on up to 1200w from my 850w and could add another 200ah of batteries.
edit: Minus the Orion unit of course as this is designed to go on a motorhome with an alternator.
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Zwy
Solar Wizard
I should quit posting here and helping people and instead spend the time creating a webpage like that with all those affiliate links. People here don't listen anyway as a poser on the internet can post something and it's gospel.
AfterShock
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I actually do appreciate all the help that I've received on here. For a rookie like me, it's difficult to know where to even start. I would say that this discussion was more productive than most when I've had to use a forum for help.
That being said, even knowing all the components I needed left me with a lot of questions, like how to set up the wire, which gauge of wire to use, where to install the fuses, etc. That explorist website actually had the best videos and the wiring diagram includes all the parts needed. Plus if you actually click on those items, they link to Amazon so I am not sure what the profit he would get out of that, other than selling his diagrams for $10 in high res.
Either way, thanks a lot to all of you. I may have more questions when time comes to install all this stuff ?
chrisski
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As you start to learn more you'll see some things in those videos that you probably would not include in your build. For me it was the fact that audio circuit breakers were used by the YouTube channel instead of properly rated DC circuit breakers.
When I measure wire, I really lean on the conservative side, so thicker the better. I look at wire and connector Ampacity. For example most MC4 connectors are rated 30 amps or less, so once I have more than that those are out. I also look at voltage loss over distances. I wanted to set my system up 1S6P, but voltage loss became too large for a reasonably sized wire run of 50' each way, so I went with 3S2P. There's a couple other things, but this is the calculator I use:
www.calculator.net
Since fusing and wires is such a critical thing, its best you work through that yourself, but you'll get plenty of help here.
When I measure wire, I really lean on the conservative side, so thicker the better. I look at wire and connector Ampacity. For example most MC4 connectors are rated 30 amps or less, so once I have more than that those are out. I also look at voltage loss over distances. I wanted to set my system up 1S6P, but voltage loss became too large for a reasonably sized wire run of 50' each way, so I went with 3S2P. There's a couple other things, but this is the calculator I use:
Voltage Drop Calculator
This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.
www.calculator.net
Since fusing and wires is such a critical thing, its best you work through that yourself, but you'll get plenty of help here.
