I am about to install a small inverter for the refrigerator and realize I have power at the inverter panel while connected to shore power. I thought we had a transfer switch that only put power to that panel when there was no other power source. Am I misunderstanding the purpose of that ATS?
The inverter breakers take power straight THROUGH the inverter when plugged in. In the event you don't have shore power you can turn on the inverter and ONLY those inverted breakers will have power.
Do you still have the original inverter? You have two transfer switches under the bed, one for shore and one for the inverter/generator.
The original inverter didn't have pass through capabilities, hence the need for the second ATS, power at the inverter was only used to activate the internal charger/converter.
The inverter is a Xantrex sw 3012 but the factory transfer switches are under the bed. I thought the inverter panel was cold until the inverter came on. The inverter is wired the way I bought the coach. If they were pass through from the factory that would explain the power at the panel.
The SW3012 does have pass through capabilities unlike the original, either way the main transfer switch powers all your circuits when on shore power.
Regardless, you can add a small inverter for the fridge with a built in ATS, or just put the fridge on a dedicated circuit that always runs off the smaller inverter. Several members have added a dedicated inverter for the fridge, I just run mine off the main inverter.
Not my fridge, but all my electronics are are a small inverter wired directly to battery. I figure when running down the road, alternator and solar will keep batteries charged, when parked and on SP/GEN, inverter/charger, and solar will keep batteries topped off. Don't have to worry about ats problems.
If a problem with small inverter can just move electronics plug to big inverter and use it.
I agree Jim, I eliminated (bypassed) my secondary inverter ATS when I upgraded the factory inverter as well.
That is the plan other than adding a DPDT switch suggested by Roger so just flip a switch with a problem with the small inverter, which isn't so small after all. The Victron Phoenix 1200 came yesterday much larger than I expected, but does fit under the bed.
Switch is good idea, mine is manual. Cut line from inverter subpanel to coach fwd [electronics] receptacles, and put plug on it, and plugged into small inverter. On fwd receptacles breaker on subpanel, put receptacle on it, so will have move plug from one to the other in case of problem. I have an east west bed so have a bit more room.
Cman,
We also use the DPDT manual switch for our small inverters that drive each independent appliance. This lets us switch from shore/generator to inverter, simple and dependable the KISS theory.
Mike
I did mine with the plugs, because I did the same mod with the fwd ac on the main panel. Normally leave ac plugged in main panel, but when I want to run it off inverter, just plug it into inverter sub panel receptacle.
I know of no one other than here running smaller inverters to invert local loads. The bigger inverters have a max efficiency that is higher and over more watts output.
If you are trying for max efficiency a smaller transformer Victron at some output level shows more efficiency than the bigger transformer American made brands,
Each foot of 12 volt wire consumes power.
That's why Foretravel located the batteries next to the inverter with large cables then distributed the 110 volt power.
So does every other rv made as far as I know.
The smaller inverters are to get rid of the high idle amp issue. My Xantrex SW 3012 will eat up 24 ahrs during 8 hours of sleep just at idle. Can't turn it off or it will screw up the timing on the residential ref. The efficiency level doesn't come into idle conditions.
I guess most Foretravel owners are smarter than owners of SOB! The distance between my small inverter to the 3/0 coach battery cable on the boost solenoid is about 18 inches. Really do not think much voltage drop or resistance when running 200 watt load through 3/0 cable.
Bob,
Do what makes you happy and we will do what makes us happy.
Mike
Craneman go to Beamalarm.com then to rv technical help then to adding an additional inverter. I got power for mine from the isolator, and put the inverter under the bed with the rest of the electrical. Been working for 3 years now wit a cheap 1000watt inverter.
That is where it is going and hooked up to the house side of the boost solenoid at this time. I had to get an inverter that could power a 22.6 cu. ft. refrigerator so the cheap one I had previously bought will get repurposed some how.
Mine is an older unit and it does shut down. Once morning comes the 1450 watts on the roof make efficiency moot. I can run the microwave while still putting 500 watts into the battery. My only issue is getting through the night and having 12.2 volts or more in the morning. Just to add the Victron Phoenix 1200 is 92% efficient.
At what power output? Where exactly is it 92%?
Does it really matter where the peak efficiency is? Its output will surge on refrigerator start-up at 1200 watts and run it between 133 and 193 watts. Then with satellite and television on, it will rise again to whatever their draw is. Throw in computer charger, Netgear charger, phone chargers all on the same circuit. This is only for when solar is not available. There is no perfect target for the 92%
Chuck, your inverter sub panel is powered by the main panel (landline or generator) through the ATS switch at the foot of the bed. If there is no land line or generator power then the ATS switches the inverter sub panel to the inverter supplied power.
Unless your original wiring has been modified the inverter is not supplying power to the inverter sub panel when there is land line or generator power.
Use the maximum 12v cable that you can connect to your smaller inverter. The maximum length should not exceed that which will exceed a 1% voltage loss. This is based on amps at 12.5 volts to produce the maximum small small inverter output plus a bit for efficiency losses. The plus cable should include a fuse rated for about 50% more than the maximum current and a switch.
This is a good tool for calculating wire size, loads, lengths and voltage loss.
Bos'ns' Corner - Wire Size Calculator (https://baymarinesupply.com//bosns_corner_wire_sizes)
Roger that was the question at the beginning of this thread. I had the main power breaker on and connected to shore power. When I turned off the inverter circuit breakers the power was cut off to each circuit. Does that mean it has been modified? The 12 volt power supply wire to the inverter will not exceed 3 ft.
Think the inverter/[SP/Generator] ATS should have supplied power to the inverter subpanel.
If you shut off breaker in your subpanel, of course no power.
The circuit breaker to the inverter on the main panel?
As originally wired, If you have the land line on then it powers the ATS to switch it to use land line power from the main panel to the inverter sub panel.
If you shut off the individual circuit breakers on the sub panel then each of those circuits will be off. The sub panel will still be powered. If you shut off the main breaker on the sub panel then the sub panel is off.
If it has been modified then the sub panel is always powered by the inverter either as it passes through 120v from the land line or the generator or when they are not available from the inverter. Your OEM inverter circuit breaker on the main panel is probably only 20 amps, enough for the original inverter. That means the max you can pass through is 20 amps. If you want to increase this then all of your wiring to the inverter and back to the inverter panel needs to be bigger as well as bigger circuit breakers.
When I bought the coach it had been upgraded to a 3000 watt inverter by Ron Hawkins' business, Innovative Coach Works Kansas maybe the wires have been upgraded too. What gauge wire from the inverter to the panel should there be. It looks like welding cable from the batteries to the inverter. I can check their ga. tomorrow. Everything has been working fine since I bought it in 2015.
This was his personal coach.
inverter wars "crop dusting" has been (and will continue to be) deleted. Poster has been warned.
Thanks Michelle for tidying up.
Chuck, the original inverter/charger probably had 3/0 cable from the power posts behind the white panel in your main bay to the inverter. These feed power to the inverter to create 120v or get power from the charger to charge the battery. As chargers and inverters get bigger so does the requirements for wiring. My Victron uses two incoming 3/0 plus and minus cables.
The OEM 120v wiring from the main panel to the inverter is sized for 20 amps and has a 20 amp circuit breaker (in mine and likely most coaches of this vintage). This is plenty to run the OEM chargers. Newer chargers that can do 120 amps are OK with that size wires (most likely 12 ga)
On the inverter output side a 2400 watt inverter can put out 20 amps and more in surge. I think FT used 10 ga wire on the output side to the inverter sub panel. Bigger inverters can generate more watts and more 120v amps which means bigger wires are needed.
If you want to get rid of the OEM ATS used by the inverter and pass 50 amps from the land line through the inverter and its internal transfer switch to the inverter sub panel then the main panel circuit breaker to the inverter needs to be 50 amps, the wiring needs to be much bigger to the inverter and much bigger from the inverter back to the inverter sub panel. Maybe 4 ga. And if you have a Victron Multiplus or a Magnum Hybrid that can pass through power and invert at the same time then maybe even bigger. The Victron will pass through 50 amps and invert to add another 14 amp (about). For that, wiring to the inverter sub panel and the circuit breaker in the inverter sub panel need to be even bigger. And most folks forget that you should add a circuit breaker panel close to the inverter with an appropriately sized circuit breaker for this source.
Someday I will get around to this. Rght now I use the sub panel powered by the main panel through the existing ATS. Part of the challenge is wiring routes and the space available in the sub floor cavities into the space at the end of the bed. It is very tight.
Roger,
I am happy the way it is wired now. I have never needed the output power of the SW 3012, but 3000 watts came with the coach. If it had the multi-plus, I wouldn't even be going the small inverter at this time. We make it through the night with 3, 6 year old Lifeline AGM's and 1/2 hour of generator time. Some days no generator at all. I am preparing for the future when I have the 6th panel up and 6 335-6 batteries. At that time I want to be able to not need the generator except under hot days when air is needed. The low idle inverter will be of much help then.
Thanks again for your input on this project.
Chuck
Craneman, most likely the way your rv is wired, you are only using one half of the capability of the SW3012, so you do not really have 3000 watts available, however you do have a great unit with 150 watt charger with many changeable settings thru the remote.
To see if you are using the entire 3000 watt capability you would have to look at the AC input and output connectors on the SW3012. I would expect for you to see only one of the two line inputs and only one of the two outputs being used.
Those interested may check out the attached manual for the SW3012 and the installation guide for the SW units from Xantrex. In order to get 3000 watts from the SW3012 you need to use both line inputs of 120 V line inputs from the 50 amp service coming in. See the attachment for the manual, the section on wiring the AC input and output of the SW3012.
I have owned two SW3012 in previous rvs, and found them excellent, however because of the rv wiring in the two Monaco Signatures, I used only one line of the two line inputs from the 50 amps coming in.
When I bought my current FT I chose the SW2012 as I knew I would only need it's 30 amp AC input and output for the FT wiring.
To be fair in comparing the two, the SW3012 has a 150 amp charger, the SW2012 a 100 amp charger. Given the choice again I would choose the SW3012 for the larger charger over my current SW2012. I also attached remote instructions to get an idea of how flexible your SW3012 is thru the remote control.
If ever having trouble with the SW3012 after changing settings you can load the defaults by doing so thru the remote. At one time I had created an issue after changing the low inverter cutout from 10.5 to 11.8. I had to change back to the 10.5 default. My issue was when I ran the toaster along with the microwave, the inverter would shut down as it saw less than 11.8V. At the default 10.5 all is fine.
You are right, it is only using one input and one output. I read the information back when I first got the coach and decided 1500 watts was more than I needed so left the wiring alone. It has no problem with the microwave or the Cuisinart coffee maker in the mornings. I do like the fast charging, my only gripe is the power it draws at idle at night. If I ever want to do one of the mods posted about running the front air while driving without the generator I will add the needed wiring at that time.
Don't know if this will help or if your coach is wired the same but my coach has a double outlet in the refrigerator compartment. Each is on a separate circuit. I don't run my refrigerator on AC unless I am hooked up to shore power. I disconnected one circuit from the panel (that powers the inside and kitchen outlets as well as the outside outlet and one of the refrigerator outlets) and use an inverter to power that circuit.