New Project plan, please critique

[Mark44]

Hey everyone,

Relatively new here, and after discussing and listening for a while, I think I have a design in mind for my Fifth Wheel trailer.

I have attached a schematic and would appreciate any and all constructive feedback.

Likely I will try to do the battery and the Charger first, then the inverter, and finally the solar.

Thanks in advance for your time and consideration. If you suggest any changes, please be specific if you can and provide links to supporting documentation.

N.B. I have not included negative or ground busbars for clarity in the diagram. They are anticipated.

 

[John Frum]

Is there a power loop between your psu charger and your inverter?
Is there any integration with the trailer's legacy electrics?

 

[Mark44]

Hey @smoothJoey,

Thanks for the clarifying questions. Yes I was concerned to see that there likely is a loop with the charger from the inverter. How best to isolate those two circuits?

Second question, yes I will use the panels already in the trailer for distribution. I anticipated removing the converter/charger that is in there, but leaving the distribution network. I hope that the input from mains (the plug fixture etc.) will work well regardless of the destination behind them, so cutting out the converter/charger would not be a problem.

The newer charging source will be from the truck alternator. The alternator will charge while driving. The charger will work when shore connected or Genny connected.

 

[John Frum]

I suggest you get a ul-458 listed inverter/charger.
Those have an automatic transfer switch which takes care of the neutral/ground bond.
Then you can get rid of your psu charger and your legacy converter.
If your trailer have a 7 pin umbilical and breakaway system I suggest you isolate them and leave them be.

 

[John Frum]

Just to be clear it looks like you have 3 un-synchronized ac power sources attached to the same bus bar.
That won't work.

 

[Mark44]

I get the idea with the un-synchronized AC power sources. Actually, they will all be isolated as follows:

The Mains power will be from a power pedestal when hooked up at a campground.
The genny power uses the same cord as the mains plug and therefore only one of those will be active at any time.
The inverter power source does need to be isolated, or at least switched I suppose, since I do not want it pushing power when Mains or genny power is applied. So transfer switch it is.
As far as the UL listed Converter Charger, I understand the recommendation, but want to try and do this another way, both to save money, and to prove I can do it.

Meanwhile I am checking out available in store options for converter /charger!

 

[John Frum]

Meanwhile I am checking out available in store options for converter /charger!

converters turn ac into dc
inverters turn dc into ac
you will want to look at ul-458 inverter/chargers

 

[Mark44]

Gotcha, sorry I misread the first post.

 

[John Frum]

This issue with neutral/ground bonding is...
Neutral and ground must be bonded and they must be bonded in only one location.
When you are attached to the pedestal the bond is upstream of the pedestal.
When you are not attached to the pedestal the bond must be in your setup.
That is why I recommend a ul-458 listed inverter/charger.

 

[Mark44]

I have been thinking about this as I research possibilities.

Is there any reason I cannot use the existing WFCO 55A power center?

I suppose it will limit my draw to 55Amps, but that's OK for me.
I think this might solve some of the issues with my design?

The bond of neutral/ground appears to be taken car of that way yes?

 

[Mark44]

So effectively, I would just be swapping out batteries, and adding a dc-dc charge feature from my alternator on the TV.

First step anyway....

 

[John Frum]

I have been thinking about this as I research possibilities.

Is there any reason I cannot use the existing WFCO 55A power center?

What is the exact voltage the WFCO produces?
You would also have to ensure there is no power loop between the charger and the inverter?

The bond of neutral/ground appears to be taken car of that way yes?

Probably not.
You need to dynamically switch the neutral ground bond.
Its a life safety and fire safety issue.
I'm not an electrician so I don't want to say much more about this.

 

[Mark44]

I get that. Since I am going to use the unit that tis there (if I go this way), it already does the entire sequence, as I use it now with a FLa battery.

Really the only difference in stage 1 will be changing from FLA to LIFEPO4, and adding a charging circuit from the Alternator on the Tow Vehicle.

Thanks for your thoughts.

 

[John Frum]

I get that. Since I am going to use the unit that tis there (if I go this way), it already does the entire sequence, as I use it now with a FLa battery.

I doubt that your current setup dynamically switches the neutral ground bond.
As for charging...
Most converters are not a good solution for charging lifepo4
Thats why I asked about the voltage.
Also is it a converter or is it a converter/charger?

 

[Mark44]

SmoothJoey,

I need to get the manual for it (its in the trailer of course), and get the stats to accurately answer your question.
When using the trailer, there are both 12 volt and 110v AC systems. it also charges the battery at (I believe) 55Aa.
It is both a converter/charger, and also contains an inverter.
I will try and get the specs so I can speak more knowledgably.

 

[HaldorEE]

You might get more attention if you post this in the correct forum (Vehicle). This sub-forum is for DIY electronics (as in home built electronic equipment).

 

[HRTKD]

Is there any reason I cannot use the existing WFCO 55A power center?
I suppose it will limit my draw to 55Amps, but that's OK for me.

Yes, the WFCO power center can be reused. That's what I did, but I haven't taken my trailer to the point where I'll be integrating an inverter into the existing AC system.

Doing the project in small steps sounds good at first. But it would end up costing more money and involve rework. As suggested by smoothJoey, an inverter/charger unit resolves the whole charger loop issue. It also reduces the complexity of wiring. An inverter with an AC input is critical to keeping the landscape simple. Without an AC input you'll need an automatic transfer switch to prevent the inverter and shore/generator from sending AC to the WFCO at the same time.