2022 28BH Inverter Prep

[allenrude]

Hi All, i have a new 28BH and see in the breaker panel i have 2 30 AMP breakers marked for Inverter Prep. Not clear however what that really means, nor what additional i would have to do (other than add an inverter) to do a complete install. Has anyone taken this to the next step from here? Thanks, Al

[klwagner52]

Hello Al,
I just purchased a Reflection 280RS and have the same question that you have. I believe there has to be a transfer switch in our units, however, one response that I got back from Grand Design says that is not true. The breaker panel is unique in that it appears to me with some basic ohm tests, that one of the 30 amp breakers is tied to the main AC line 1 bus. This then would supply power to other breakers in the panel with the exception of the 12 volt converter/charger. That makes sense to me, but the other 30 amp breaker is a mystery to me. It appears to be tied to the neutral bus. I have requested a wiring diagram - that would help greatly in determining how this all set up. Other wise I am just going to have starting to remove panels and do some tracing of wires - when I do I will document it and gladly share it with you. Question for you - do you have a loop of Romex wire inside your battery bay? I believe this is what ends up going to those 30 amp breakers, but without a transfer switch being used, they would cause a short circuit. The search will continue.

[allenrude]

Hi Ken, thanks ofr getting back. I will be working around in the breaker box this weekend installing a hard wired Power Watchdog EPO so will see if i have any unattached AC wires in a coil somewhere unattached that would be used for an inverter. appears that the prep was designed for a dealer to leverage and not necessarily for the enterprising owner to address on their own. Will stay in touch..

[klwagner52]

Hi Allen, well with the help of GD I was able to figure out the Inverter Prep Wiring. I will be updating a schematic diagram shortly and will forward a copy, but their design is really quite simple. The first 30 amp breaker labeled "Inverter Prep" in the breaker panel is a 30 Amp Shore Power out. The second one is Shore/Inverter Power back into the sub panel and this is used to supply power to the General outlets, the GFCI, and the Microwave. A poor mans switch would be to wire a 3 prong female plug onto the Shore Power Output, and a male plug to plug into the inverter. When connected to shore power just plug the two together. The better solution is to wire a 30 amp two pole transfer switch into the circuit and let it do the switching for you. I am researching a good switch for the job and will add the info to the schematic showing how to connect everything.

[howson]

I am researching a good switch for the job and will add the info to the schematic showing how to connect everything.

Look forward to reading your updates on this, Ken. Will be good information for the Reference Material section. (Glad you're here!)

Howard

[klwagner52]

ac_wiring_280_rs.pdf
Disclaimer - my drawing package has some limitations and for clarity I did not show all of the Ground and Neutral discrete wires, only the key ones are shown. I am looking at using the Go Power model TS 30 transfer switch for my application, When wiring in the inverter to the battery, insure that you use the correct wire size for the size of inverter that you are installing. The largest inverter that can be used is a 3000 watt. Hope this is helpful.

[klwagner52]

Hello, I have a 280RS and have just completed the installation of a inverter and a transfer switch to my unit. Before I go into the details I wish to point out that the 160 watt solar package that is preinstalled is only to support the 12 VDC refrigerator. If you use the 12 Volt system of other items in your unit and you are not connected to shore power, you will most likely wake up to a dead battery. My package included a standard flooded cell deep cycle battery, if you run this type of battery down below a 50% charge, it will damage the battery and will shorten its life. The roof mounted solar panel is just enough to keep the refrigerator happy but nothing more.
So if you are going off grid you will need to spend some money and upgrade your solar installation. I purchased qty 2 200 Amp Hour lithium batteries and two additional fold out 100 watt panels. After using my system I will be adding a third 100 watt panel soon. I went with the fold out units because they are more flexible to setup and capture more of the sun rays during the day. Roof mounting your panels is good if you always go to the same location and can tilt them up to capture the sun, but when boon-docking you may not always be able to park your rig in the ideal location to capture the sun.
Getting back to the inverter prep that GD did for these units. The circuit breaker panel is actually broken down into 3 sections. The Line 1 50 amp, the Line 2 50 amp, and the "Inverter Prep" 30 amp section. The factory wired a orange romex cable to the first Inverter Prep 30 breaker and then looped it out to the front battery compartment, and then back to the second Inverter Prep 30 amp breaker that feeds the 3rd sub panel. To install a inverter into the system, you must cut the cable located in the battery compartment. Then you need to identify which is the power source side and which is the power return side to the breaker panel. You can do this in several ways, the easiest and is not recommended for beginners is to use a voltage detection device that you can buy at home depot that is used to verify hot outlets. Apply power to the shore input and let the tool tell you which side of the cut cable is hot.

Next you need to install a a transfer switch. I used the Go Power model TS-30 and it provides a AC power cord with a 3 prong connector to connect the inverter output to. Follow the manufactures wiring instructions and connect the shore power to the cable identified in the previous step and the Load outputs to the other half of the romex cable that you cut in two previously. The most difficult part of this job is bending the romex into position in the transfer switch as it a very rigid wire to work with. Take your time and insure that the ground wires are routed so as not to touch the relay during travel. I have attached a schematic diagram to support this job.

[howson]

I have attached a schematic diagram to support this job.

Nice job, Ken, on the diagram. It's the first definitive reference I've seen on how the camper is wired with the 30 Amp Prep.

Hope you don't mind a constructive critique? The 12vDC side (input to the inverter) should have fused circuit protection. I suspect you have it in the trailer, so it should show on the diagram, too.

I must admit to being a bit puzzled as to the purpose for GD installing the 30A breakers (both the Prep IN and PREP OUT) as labeled in the drawing. I'll try to explain in the paragraphs below.

TRANSFER SWITCH NC CONTACTS CLOSED
As currently drawn the transfer switch is set to provide power from the inverter as the default since the NC ("normally closed") contacts are closed. I'll assume the inverter is on and providing inverted power.

The inverters I'm familiar with that have a typical household outlet to power an appliance do not require a circuit breaker between the inverter and the 120vAC load. I assume the inverter used in the drawing has one or more NEMA outlets. That leads this shadetree (at best) electrician (me) to conclude that the 30A Prep Out and 30A Prep In breakers are not needed since the 15A Microwave, 15A General, and 15 Amp GFCI breakers provide protection for the wiring in those circuits.

TRANSFER SWITCH NO CONTACTS CLOSED
With the NO ("normally open") contacts closed, shore power is passed to the microwave, general, and GFCI circuits. The circuit is Shore > 50A CB > 30A Prep Out > Transfer Switch > 30A Prep In >15A breakers (3 ea for the individual circuits). I don't understand the need for those 30A breakers--there are (literally) tens of thousands of GD RVs out there that have the three branch circuits (microwave, General and GFCI) tied directly off of the 50A leg. In other words, Shore > 50A CB > 15A CBs.

Random thoughts this morning...time for a second cup of coffee. Hope you receive this in the constructive manner intended.

Howard

[SASurvival]

HI Ken, Thanks for the info on the "Orange Romex", do you have a photo of the exact wire in the battery compartment, i did check and do not see it. It is looped in/out of the breakers, i see it disappear down a hole underneath but i do not see it arrive in the front hold/battery compartment. (weather not good at the moment to lower the under belly to trace where it goes. I was going to add cable but hopefully this will save time. I will be soon doing the same idea as you, when the weather warms up, will be adding 560Ah Lifepo and adding an additional 400w of solar to the 165w on the roof, i'm hoping all that will be good for off grid.

[Bob R]

Related question,
Ken, I noticed in your wiring diagram that you have a 50amp set up as do and yet you went with a 30amp transfer switch... if I want to wire such that I may eventually feed all of my ac input from solar I will have to use a 50amp transfer switch, true?

Thinking like the poor mans version of switching with a 50amp male for input and a female for output from grid and inverter...

[Marc61447]

Hi guys new here.
I'm picking up my own 2022 28bh in a week or so. I stopped by deal today to look it over and saw the Same inverter prep. 2 30amp breakers in panel and a wire loop in the front compartment. Is it possible it's set up for 2 inverters? One for each phase of the panel?

[Country Campers]

Hi guys new here.
I'm picking up my own 2022 28bh in a week or so. I stopped by deal today to look it over and saw the Same inverter prep. 2 30amp breakers in panel and a wire loop in the front compartment. Is it possible it's set up for 2 inverters? One for each phase of the panel?

No it is only set up for 1 inverter.

Brian

[ncitro]

Hi guys new here.
I'm picking up my own 2022 28bh in a week or so. I stopped by deal today to look it over and saw the Same inverter prep. 2 30amp breakers in panel and a wire loop in the front compartment. Is it possible it's set up for 2 inverters? One for each phase of the panel?

To expand on what Brian said it's possible, but you would abandon the inverter prep and "go it alone". No problem with that, and if you want to run more off of the inverter besides the two circuits on the inverter sub panel that's what you need to do anyway.

[Marc61447]

Thank for the reply guys.
I don't have the RV in my driveway yet. When I looked at it the wire loop in the front compartment looked to be regular Romex with one hot one neutral and one ground. So if you wanted to go with a victron Multiple plus 2 you would have to rewire.

[Marc61447]

No it is only set up for 1 inverter.

Brian

Hi Brian
Would an inverter charger work then? One side of the looped wire as in the other as out? If you think that would work Besides disconnecting the OE converter would I need to do anything else? Any ideas on if it would feed both sides of panel?