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MPP Solar vs separate components

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beckkl

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Hello everyone, I was wondering what the prevailing opinion is on going with an MPP Solar Unit vs separate MPTT charge controller/inverter/transfer switch etc. I just bought a small travel trailer, and am looking to put 200W of solar panels on the roof. Going to stick with the single FLA deep cycle for now, but plan to upgrade that at some point so I can get it off the tongue. I had everything picked out, but then saw the MPP solar units. My main concern based on Will's review is the fan noise. It would be mounted under one of the bunk beds, and right now the WFCO unit's fan is already a bit annoying, but mostly because it switches on and off depending on what is on.

The ease of installation is not a big concern as I have a fair amount of electrical experience, but the price is nice. Was wondering where others in similar situations might have landed?
 
Last edited:
The one thing that I like about pieced together systems is the ease of upgrading one part of it as your needs grow. I also feel you get a better understanding of how it all works when you have to put it together.

But that's just me.
 
Brewman said:
The one thing that I like about pieced together systems is the ease of upgrading one part of it as your needs grow. I also feel you get a better understanding of how it all works when you have to put it together.

But that's just me.
Click to expand...
Very true. I also liked some of the remote control aspects in going separate. My initial thought was to go with the Rich Solar 40A mptt controller, a Giandel 1200W inverter, and the xantrex ATS. I liked the idea of remotely switching the inverter on and off. The only part I was getting hung up on was what to do with the DC charger built into the WFCO.
 
Yes, its a power distribution panel, with a DC converter/charger for the 12V bus. It is a bit of a conundrum to set it up for the following:
1.) When on shore power --> WFCO panel handles AC/DC (including charging of battery)
2.) When not on shore power --> Inverter powers WFCO panel (AC only) , but 12V runs off the battery.

It would be easier I guess if I just disconnected the battery from the WFCO and let either shore power or the inverter power both AC and DC, but the idea of going from DC-->AC-->DC seems pretty inefficient. I know you can rig a relay or something to disconnect the converter when the inverter is running, but was hoping there might be a better solution. I'm sure I am missing something.
 
I'm using an Aims inverter/charger with ATS (no solar charge controller) in my RV, and I'm happy with it so far. As for the WFCO DC converter, I just turn off the breaker for that circuit. The Aims unit provides 12V when connected to shore power, and of course charges the battery. Plus, it is a fairly quiet unit.
 
In reality though, my main concern is having power, not charging the battery. If I have shore power, I don't really care if the battery isn't charged, and am happy to wait for the solar to catch up. I could always charge the battery with the truck's alternator if I had too I guess.
 
beckkl said:
Yes, its a power distribution panel, with a DC converter/charger for the 12V bus. It is a bit of a conundrum to set it up for the following:
1.) When on shore power --> WFCO panel handles AC/DC (including charging of battery)
2.) When not on shore power --> Inverter powers WFCO panel (AC only) , but 12V runs off the battery.

It would be easier I guess if I just disconnected the battery from the WFCO and let either shore power or the inverter power both AC and DC, but the idea of going from DC-->AC-->DC seems pretty inefficient. I know you can rig a relay or something to disconnect the converter when the inverter is running, but was hoping there might be a better solution. I'm sure I am missing something.
Click to expand...

The nice solution here is an inverter/charger.
inverter/chargers are actually inverter/charger/transfer_siwtches.
the mpp is all of that plus a mppt solar charge controller.
I just did a big write up on how to integrate it.
Would be happy to help.
 
smoothJoey said:
The nice solution here is an inverter/charger.
inverter/chargers are actually inverter/charger/transfer_siwtches.
the mpp is all of that plus a mppt solar charge controller.
I just did a big write up on how to integrate it.
Would be happy to help.
Click to expand...
Nice, do you have a link to the writeup?
 
beckkl said:
Yes, by the sink. I have a few laying around and could also wire one into the WFCO box
Click to expand...

The existing one is fine.
We can use it to test things out.

Before I forget the big issue here is if the MPP can switch the neutral ground bond.
When on shore power the bond should be somewhere upstream out of your control.
When on inverter the bond should be within the inverter.

The last guy I was helping with this said he checked and the mpp could do this but I want independant verification cause the guy wasn't super reliable.
Will post the instructions later today.

Am I getting too techincal?
 
I’ve got the MPP 2.4 kWh model.
My thoughts and observations:
Positives
  • you’ll require less space for the AIO (All-In-One);
  • wiring is less complex;
  • programming is mostly in one place;
  • easier monitoring through a single interface.
Negatives
  • If it breaks you lose a number of your power elements (SCC, inverter, automatic transfer switch). Easier to replace a single element in a non-AIO system;
  • upgrading to a higher power level may be more expensive. You may only need to replace one item in a non-AIO
  • The charge and discharge lines are one and the same in as far as the inverter is concerned, so a BMS that can stop charging or discharging effectively ends up doing both when it does either;
  • you still need a method to ensure you don’t over-discharge through your DC service draws. Either a BMS or another battery protect device.
If I was designing an AOI I would route DC load through the AOI so it could protect over-discharge on both A/C and D/C, add a DC buck/boost converter option, a BMS manager with optional BMS sub-boards for each battery, bays for A/C and D/C sub-panels and breakers, and a breaker for the solar input lines.
Finally, I would make it user upgradeable and repairable by making each subsystem one that could be pulled and replaced like a circuit breaker in a household breaker box.
Power and control buses would be used for distribution and control.
So basically a plug and play power system. Order what you need to start then upgrade as you go. No messy wiring, trying to find space for new elements and having to retire.
 
Here are the instructions.
Hope to get many eyeballs.
Code: 
WARNING: 120VAC can kill so be careful
Baseline test
    test the shore power for correct polarity and voltage before connecting the rv to the pedestal
    if success
        connect the rv to the shore power pedastal
        test a gfci socket using the test button on the socket
    if success
        test the same socket with the socket tester
    if success
        try running a double insulated(2 prong) appliance from the gfci socket.
    if success
        try running a grounded(3 prong) appliance.
    if success
        test a dc load
    if all of the above was sucessful
        disconnect the shore power
DC
    disconnect the main battery negative cable from the battery terminal
    pull the main DC fuses in the WFCO panel
    manually trip the master AC breaker in the WFCO panel
    disable WFCO converter by manually tripping its breaker
    remove the WFCO converter breaker and wire nut the hot wire to make it safe
    *Optionally remove the converter by disconnecting it from the AC and DC panels
    Connect the inverter/charger dc negative terminal to the battery negative terminal with an appropriately sized wire, shorter is better.
    Connect the battery positive terminals to the inverter/charger positive terminal via an appropriately sized wire, shorter is better.
    The positive leg should be fused as close to the battery terminal as possible.
    Make the initial connection via a 50 watt 25 ohm resistor to prime the inverter/charger capacitors for ~5 seconds.
    Make the permanent connection.
    The inverter/charger should now power up.
    If success
        power the mpp down
        reinsert the dc fuses into the WFCO panel
        power the mmp up
        test a dc load.
    if success
        configure an appropriate charge profile for the house batteries
AC
    Power down the inverter charger
    Manually trip the master AC breaker in the WFCO panel
    Disable WFCO converter by manually tripping its breaker
    Integrate the mpp AC Live Netural and Ground like this
        shore_power<->surge_protector<->breaker<->mpp_all_in_one<->WFCO_panel_AC_master_breaker
    Connect the shore power
    power on the inverter/charger
    Close the master AC breaker in the WFCO panel
    verify that the inverter is bypassing shore power via the inverter panel.

    test a gfci socket using the test button on the socket
    if success
        test the same socket with the socket tester
    if success
        try running a double insulated(2 prong) appliance from the gfci socket.
    if success
        try running a grounded(3 prong) appliance.
    if success
        test a dc load
    if success
        disconnect the shore power
        test the same socket with the socket tester
    if success
        try running a double insulated(2 prong) appliance from the gfci socket.
    if success
        try running a grounded(3 prong) appliance.
    if success
        test a dc load
    if success
        very that the batteries charge appropriately
    if success
        do any additional invert/charger configuration as required
 
Any thoughts on how loud the MPP units are? If there is loud fan running all the time, it is sort of a deal breaker. I have no real way of isolating that sound.

Specifically the 1012LV-MS
 
beckkl said:
Any thoughts on how loud the MPP units are? If there is loud fan running all the time, it is sort of a deal breaker. I have no real way of isolating that sound.

Specifically the 1012LV-MS
Click to expand...

If the fan is an issue then open it up - yank the fan out - and put a better fan in ... I've done that a few times - pull the $1.60 Chinese fan out ... put a $15.00 German fan in that moves twice the air and is silent ... (before you ask I have no idea where they get these German fans from - probably Amazon or EBay) ...
 
KBWaldron said:
Negatives
  • If it breaks you lose a number of your power elements (SCC, inverter, automatic transfer switch). Easier to replace a single element in a non-AIO system;
  • upgrading to a higher power level may be more expensive. You may only need to replace one item in a non-AIO
  • The charge and discharge lines are one and the same in as far as the inverter is concerned, so a BMS that can stop charging or discharging effectively ends up doing both when it does either;
  • you still need a method to ensure you don’t over-discharge through your DC service draws. Either a BMS or another battery protect device.
Click to expand...

I am against any type of All-in-ones for the Very reasons listed as Negatives -- these are pretty substantial considerations ... if i want to upgrade just my inverter you have to do the entire thing ... or your happy with the inverter but need a larger SCC ... etc etc
 
beckkl said:
Any thoughts on how loud the MPP units are? If there is loud fan running all the time, it is sort of a deal breaker. I have no real way of isolating that sound.
Click to expand...
Reports are that they are annoyingly loud. I think Will Prowse has a video on the MPP.
 
ghostwriter66 said:
I am against any type of All-in-ones for the Very reasons listed as Negatives -- these are pretty substantial considerations ... if i want to upgrade just my inverter you have to do the entire thing ... or your happy with the inverter but need a larger SCC ... etc etc
Click to expand...
All good points. Just thinking that the chances of needing to upgrade is minimal. There is really only so much draw in a small camper. Just need to keep the water pump and propane appliances running, tablets charged, etc. The cost of the MPP is less than a decent SCC and inverter. But i tinker with 3d printers, so I get the draw of wanting to keep things modular and flexible :)
 
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