Partial re-wire of my trailer - need help please

[Chorky]

Hey all, Lots of info here

So I'm embarking on rewiring and adding some stuff to my standard trailer. I have a 2011'ish Keystone Springdale 179QB. It has been my house for the last 4 years, and likely will be for the next 4 years. My current situation is slightly unknown and variable for reasons; however, the point being is electricity is unknown. Currently it is (and has been) hooked up to shore power; however, that may change. vPower availability is kinda unknown in terms of power outages currently, and power availability in the near future. I also may be purchasing my own property and may need the capability to be fully off grid for a year until getting power put in.

For the most part I understand the basics of 12v, but I know little for 120v things. There are some questions and concerns I have with the trailer wiring as it currently is, and things I wish to do. Here are some main bullet points and pictures without going into much detail.

As is currently: (note the information for "Max IN" and "Max OUT" is for the converter as per manufacturer specs)



Caveat:

• This all started mostly due to the standard factory absorption fridge dying about 3 years ago. I have since used, full time, a 64'ish L SnoMaster LP fridge. It works great, but is in the way, so I want to relocate it as a 'deep freezer' and a backup since it can be powered by either 12v DC or 120v AC
• I have purchased and plan to pick up and install soon a Insignia residential fridge. According to the spec sheet it pulls 0.91a @ 120v. I do not know the wattage?? Maybe 109.1w?
• Due to various uncertainties, I plan to hardwire my 3500w 30a Champion dual fuel generator to the main 30a in, in the event there is no other power source (such as not currently having solar, or in the winter, or main power outage, batteries low, etc...)
• I do plan on a solar system, although it may be a while, but hopefully in the next few months, but not fully sure...currently I have full power hookups, but some funny business is going on so I really want to be self-reliant
• I wish to have the 12v SnoMaster fridge relocated (for a 'deep freezer') and will need to decide to continue running it on 12v, or use 120v. I believe 12v would be better based on how many items are already on the 120v side of the trailer, and not needing the inverter for 12v use (also, I dont know how many amps a inverter pulls, for example if my fridge pulled 7a on 12v, what it pulls in total (including the inverter needs for conversion) on 120v))
• I plan to have an inverter to run things purely on batteries in the event it is needed (most likely in winter to run residential fridge most the day/night until I 'top off' batteries from the genset if solar is poor, and/or shore power is not available or there is a power outage)
• I need to find where the water pump and 12v side (LP) of the water heater, and the furnace is tied into the system so I can make sure it has fuses. I feel as if it is tied directly to the converter as I have blown my 'conv/gen 15a' breaker often a few years ago when my main 30a power source was poor quality. There is currently no fuses or indication at all where it is wired, and switches may not even be fused.​

My 'rewiring' plan:




So ultimately, some questions....

• Solar - what do I need? 170, 340, or 510 w? Will the Zamp 30 even be enough? That would be the max roof space I have available...not to mention cost...
• Is a 2000w inverter appropriate? Assuming in a no power situation and running on batteries of course I would limit use. If the converter maxes out at 940w input, and the fridge is maybe somewhere around 109.1 wats, so maybe 120w for a buffer is appropriate, thus those two items would total to less than 1100w, so if I wanted to also power the monitor, computer, it seems a 2000w would be sufficient? But now what about additional 12v power draw for things like water pump, water heater, furnace, etc...since they dont have any fuses i can find, and power source is unknown...
• Batteries... I really need help here. For some reason I just cannot figure it out despite some awesome help from some folks on a truck camper plan last year. I have figured I would likely need 4 6v batteries minimum (but that is the max I can probably fit) - lifeline offers some but I cannot seem to understand their ratings. For example, one of their 6v options says "rated amp hours at 20 hour rate - 300". Does this actually mean 300 hr rating? They also stated for their 6v batteries max charging voltage should be 7 volts'ish. But if you run in series for a 12v system, I'm assuming the max voltage thus would actually be 14v so just as a normal 12v battery? Also to consider I would like to consider 4 of lifelines GPL-6CT as I will have to consider weight as an issue since mounting the generator on the front, with propane tanks - I'm probably getting close to maxing everything out.
• I am confident there is something here I am missing... I don't want to make this super complicated or expensive, since it is a springdale, but have some capability needs. I think things from the drawings are at least on the right track, but what am I missing or wrong on?
• Is my second wiring diagram (how I wish to rewire) correct? Do the genset and inverter need to go directly to the 'main 30' in order to give the entire system power? Or could I possibly have a 'genset' and 'inverter' breaker on their own breakers to backfeed, and then turn the 'main 30' OFF in order to not backfeed into the entire power grid? I will have 3 more breaker slots available after I separate the current 'Conv/Gen 15' breaker into their own respective '120's 15' and 'converter 15' breakers (as it probably is supposed to be anyway...

Lastly, even though this is my house, has been for 4 years, and likely will be for years to come, I ultimately wish to make it 'off grid' able in the event I travel, buy property and need to build, or even for re-sellability - so everything I do and install will be professional (better than factory) quality.


Thanks in advance for any input folks. Life changes have made this a necessity at least for the next 2 years minimum.

 

[Chorky]

Utilise proper interlocked transfer switching. Either manual or automatic.

Can you elaborate? What is this, and would it require me to wire the trailer in a specific way?

 

[dreadlocks]

I use a Xantrex ATS for switching my trailer between shore power and inverter power.. https://www.amazon.com/Xantrex-8080915-PROwatt-Transfer-Switch/dp/B004S5Y158

Buy Duracell GC2 batteries from Sams Club, Charge them with 12v profile.. Fit as much solar as you possibly can, nobody has ever regretted having too much solar.

 

[Chorky]

So in my case I would want a 30 amp transfer switch. I'm assuming I can find one that primarily powers from shore power, and switches to and inverter if shore power fails. But how would I wire it to say use primarily generator power if I chose to run the genset for a while to say recharge the batteries in winter when solar isn't working.

 

[dreadlocks]

Why do you need a 30A transfer switch? a 2000W inverter fits within a 15A 120V circuit.. you just wire them together on your 15A hardwired outlets, done.. you dont wanna feed inverter to all your circuits, or its gonna feed your air conditioner and onboard charger, and if you have a 120v/12v fridge its going to switch over to AC power when it shoulda stuck to DC.. the only circuit anyone wants on their inverters are the outlets.. all the other circuits should be dark if running off battery.

In my trailer I have a 30A main, a 20A Air Con, a 15A for Engel Fridge, a 15A for Electric PTC Heater, a 15A for onboard charger, and a 15A for internal/external outlets.. only that last circuit should get power from an inverter and the ATS sits inline on it.. you take the hot wire out of that breaker, wire it up to the ATS w/common and ground, then wire the the ATS hot into the breaker where it used to be, finally plug the 3-prong into your inverter.. done.

here's a photo of my setup, Inverter next to the ATS, next to the circuit box:

In this configuration my 120V wall outlets are powered by shore/generator power when available, and when the external power source is not energized it automatically switches all those outlets over to the inverter so quickly nothing will even notice it.. and when the shore power comes back, it switches the circuit back automatically just as quickly.. the priority is for external power and battery power is the failback.

 

[Chorky]

Just trying to keep consistent with the trailer as a whole. I'm not up on ac systems but if 2000w equals 15a for a AC system then that would work. But I do have a 30a 3400w genset, so I would like to be able to have full use of its capabilities.

Now as for the fridge specifically, my RV fridge keeps dying, so I bought a residential only 120v fridge last night. If power goes out, then the residential fridge would stop working - sparking this entire idea as a whole. I would like to make sure the residential fridge keeps going without shore power, whether that be batteries, solar, genset. I also travel multipel days at a time, so I'm not home to just fire up the genset. Usually gone 8-16 days at a time. So having batteries able to power an inverter that then can power the fridge for at least 3 days for me is needed. Now, I figure that wile I'm at it I mine as well rewire the entire power box to at least give the option to power a couple items from the inverter as well, in the case that say, powerlines are down for several weeks.

 

[dreadlocks]

the Genset is just shore/external power as far as anyone cares, that dont change nothing.. its the same as you are now plugged into the mains, except you put gasoline in it.. that feeds your main 30A circuit from an external plug.. what you plug your trailer into is mostly irrelevant, you still get 30A into your breaker box for your aircon and charger and outlets just as it always has and none of it cares how.

With the ATS wired up to the same circuit the fridge is on, it will automatically switch over to the inverter if shore power is lost.. so that satisfies the requirement, the fridge wont have any idea external power was lost unless the batteries are flat .

Amps * Voltage = Wattage, dont matter if your AC or DC or Marvel.. <badum tiss>

 

[dreadlocks]

My 'rewiring' plan:
View attachment 581884

lets do a thought experiment on this wiring plan of yours as it is..

So, your on battery power, your inverter is feeding your trailer input as a whole.. now your converter is powered, and trying to charge your battery, through the inverter, and off the battery.. so, your inverter is pulling 30A of power, converting that to AC with appriceable losses, using it to power your DC charger which is converting it back to DC, with more appreciable losses, and then trying to put 20A of power back into your battery.. so just sitting there, with no lights, no appliances and absolutely nothing your draining 10A constant out of your battery, in a feable attempt to recharge your battery with some failed 1st grade perpetual motion machine.

This is absolutely the wrong way to hardwire an inverter into your camper.. it needs to be far more selective and only power what you intend it to power.. Circuits such as Air Conditioners, Converters/Chargers, electric heaters should never run off an inverter.. those things would nuke your house battery bank in a heartbeat, regardless of the size.. its far better they just shut off if shore power is lost than try to continue off battery.

 

[Chorky]

Ok I see what your saying here. So I probably failed to mention that with the system on and powered by say the inverter, I would have the converter off to avoid doing just what you said of a power 'circle' if you will.

So with that in mind, if I have the converter on its own breaker and had that breaker off during times of the inverter powering the system, would that be acceptable? Or no? I dont care for the AC or things like that to be on if I'm running on the inverter. THe idea behind the inverter is essentially 100% for the fridge primarily. However, I would like to have the option to be able to power my 120 outlets, for say computer use if I'm working remotely from home (times like today). But.... Is that feesable even? That's a totally separate question but I think important. I'm not sure what size battery bank I reasonably need, if it's even possible in all reality.

But I totally understand what you mean about the constant 10a drain. I suppose I left out that detail of having the converter off while running on inverter power.

 

[Chorky]

I suppose also that my situation is more complex since it's a factory trailer in that separating the 120v plug for the fridge from all the other 120v plugs is not really possible. Now, the AC, microwave, and GFCI are on their own circuits and can be turned off easily.

 

[dreadlocks]

If you dont idiot proof this to just work always, and safely without someone having to know and remember to flip a bunch of circuits your gonna end up with a bunch of worthless lead sooner or later, if your willing to pay lifeline kinda money for the house bank, you should take the efforts to protect it from your own stupidity.. Breakers are not light switches, if you flip em on/off frequently they will wear out and need replaced sooner than later.

The only reason to have your fridge on its own circuit is if its a dual power AC/DC fridge with its own internal transfer switch, since that is not what you have.. yank that breaker out, wire it up to same breaker your outlets are on.. done.. my fridge is on its own circuit for no reason other than to let it run off the appropriate source w/this inverter in the mix.. if I put it on same circuit as my outlets, my fridge would be running off AC power all the time and never switch over to DC when shore power was lost and thus it would consume at least 10% more power using the inverter.. the fix is to put it on its own circuit from the outlets, so when shore power is lost its got no AC power and switches itself to DC.

 

[Chorky]

If you dont idiot proof this to just work always, and safely without someone having to know and remember to flip a bunch of circuits your gonna end up with a bunch of worthless lead sooner or later, if your willing to pay lifeline kinda money for the house bank, you should take the efforts to protect it from your own stupidity.. Breakers are not light switches, if you flip em on/off frequently they will wear out and need replaced sooner than later.

The only reason to have your fridge on its own circuit is if its a dual power AC/DC fridge with its own internal transfer switch, since that is not what you have.. yank that breaker out, wire it up to same breaker your outlets are on.. done.. my fridge is on its own circuit for no reason other than to let it run off the appropriate source w/this inverter in the mix.. if I put it on same circuit as my outlets, my fridge would be running off AC power all the time and never switch over to DC when shore power was lost and thus it would consume at least 10% more power using the inverter.. the fix is to put it on its own circuit from the outlets, so when shore power is lost its got no AC power and switches itself to DC.

The fridge I have on the way is 120v only. It doesnt have DC capabilities, ulnless it is DC going through an inverter to AC

Fwiw, if your generator is an inverter type or otherwise only outputs 120V it can work to your scheme.
If its dual voltage generator, 120V & 240V. You can only use 1/2 its capacity, 1700W

The generator is a inverter style - 1 30a outlet and 2 normal

 

[dreadlocks]

The fridge I have on the way is 120v only. It doesnt have DC capabilities, ulnless it is DC going through an inverter to AC

Exactly, so simply rewire the fuse box so your Fridge is on same circuit as your outlets.. its not on its own circuit because it needs it, its an easy fix.. all those wires terminate at the same spot so moving it over to the new breaker is super easy.. then you will wire JUST that circuit up to your Inverter + w/Automatic Transfer Switch (ATS).. now you can run everything off your generator, and when it runs out of gasoline in middle of the night it'll switch your fridge over to battery until you get the generator going again.. Your AirCon/Converter will simply shut off and never try to run off inverter and anything on the outlets, including your fridge has an automatic battery backup.

The 30A input for most trailers is so it can run the Air Conditioner (~18A) and still have enough left over your converter and outlets are usable without tripping breakers, the aircon its self will use a full 15A 120V circuit capacity all on its own, 50A service campers have dual air-conditioners.. otherwise without the air-con or electric heater in use, most trailers are perfectly serviced with a single 15A feed as long as you can avoid using your microwave oven and toaster at the same time.

If your gonna be using any big power tools like table saws or the like, simply plug those directly into your genset and dont even bother running em through your trailer breaker box.. they dont need the battery backup.

If your full timing out of this for the next 3 years in a boondocking situation, you really need to reduce complexity and opportunity for user error.. just having everything work and be simple for you will pay dividends.. its far too easy to become complacent with that much time and miss a step w/out realizing until its too late.. oh you forgot to check the gas tank was full before leaving it unattended? you intended to fully charge the house batteries, but oops, now you dangerously deep cycled your batteries and at best case lost some capacity because something shouldn't had ran off the inverter, at worst lost your whole house bank.

 

[Chorky]

I see what your saying and after I posted the diagrams my immediat thought was also that the inverter and genset doesnt necessary need to power the entire house. The only critical 120v component is the fridge. Of course in summer 115 degrees it would be nice to run the ac before bed, but not necessary I suppose.

So, in my existing system, my outlets (including fridge) are wired on the same breaker as the converter. So to make sure I understand what your saying correctly, the outlets and converter should be on their on separate breakers? That's what I had originally planned on doing anyway. And then the gen/inverter would be wired to the outlets (fridge) breaker only?

But, how would I prevent any backfeed to the rest of the system (ie. converter)? Are you suggesting that the fridge outlet be entirely separate from the rest of the system? I currently do have shore power, so it would be beneficial to run off the shore when available.

 

[dreadlocks]

yep put the converter on its own breaker, so it wont be powered by inverter and thats often the only way to shut it off if you need to work on DC side while plugged in.. working on the DC power system when the air con is on is super nice, trust me.

Your Gen and Inverter are two seperate things, coming in two different ways.. you Generator is hooked to your 30A main shore power circuit through the normal shore power pigtail.. that feeds right to that main 30A breaker and from there is distributed into smaller 20A/15A circuits for your air conditioner, converter, wall outlets, etc.. Your Inverter is going to be tapped inline to your wall outlets, after the wall outlet circuit breaker and will only switch over to the inverter when that main 30A feed has gone dark.. its transferring the circuit out of that dark circuit box and over to your inverter.. you will be able to test failover/and failback by simply flipping the breaker on the wall outlets, turn it off and you'll hear the ATS click and inverter fans ramp up.. then flip breaker the other way and after another click the inverter will ramp down.. you can do this under heavy load and it'll never notice switching back and forth between the inverter and the shore power.

colloquially, the big 30A pigtail power cord coming out of your trailer is 'Shore Power'.. and Shore Power is your external AC power source, it can be either/or normal 120VAC mains, or a portable Generator.. it dont matter really until you have a big onboard generator on an RV with a big fuel tank, and then that adds a whole bunch of complexity because your dealing with starters and another transfer switch and computers to have it automatically fail over from Shore Power to Onboard Genset to Inverter and fail back.. If you have an onboard auto starting generator you have little need for the inverter really unless you need to keep everything running while the genset ramps up.