Inverter Installation

[FishTank]

Hello!

I found some similar threads, but thought I would see if anyone has done this modification. We have a 21NE that we got with all the off grid bells and whistles, except we opted to install our own batteries, so there's also no inverter currently installed. I am thinking of installing this Victron unit and I'm working out mentally how to do so. With some wiring diagrams posted here I see that the WFCO power panel also has a converter to feed the DC fuses when on shore instead of the batteries. I'm wondering, why I wouldn't be able to install the inverter ahead of the panel. So it would be AC and DC into the inverter, and AC out to the panel; cutting the battery -> DC panel feed out entirely. I've included an extremely poor drawing below as well.

https://www.victronenergy.com/upload...A-120V-EN-.pdf

[oldwave]

Originally Posted by FishTank

Hello!

I found some similar threads, but thought I would see if anyone has done this modification. We have a 21NE that we got with all the off grid bells and whistles, except we opted to install our own batteries, so there's also no inverter currently installed. I am thinking of installing this Victron unit and I'm working out mentally how to do so. With some wiring diagrams posted here I see that the WFCO power panel also has a converter to feed the DC fuses when on shore instead of the batteries. I'm wondering, why I wouldn't be able to install the inverter ahead of the panel. So it would be AC and DC into the inverter, and AC out to the panel; cutting the battery -> DC panel feed out entirely. I've included an extremely poor drawing below as well.

https://www.victronenergy.com/upload...A-120V-EN-.pdf

In my latest trailer, I removed the factory converter and installed a victron multiplus 2000 va (it’s 1500 watts). Now in a Bigfoot the converter is separate, however I also,owned an escape. You would unhook the factory converter from ac and the dc feed from the panel. The multiplus would connect to the battery and the ideally through a victron lynx distributor that also would feed the 12 volt panel through the escape dc side. The output of the multiplus feeds the ac side of the distribution panel. The shore power connects directly to the multiplus. The multiplus has the transfer switch built in. High quality gear, I’m currently running mine with 400 amp hour of lithium. I’m very pleased . If you want details you can pm me and I’ll send some pics. There are also a whole bunch of talented escape owners who have done similar installations. I feel the custom charging profiles of the multiplus is very very good for lithium batteries as well as other chemistries

[FishTank]

Originally Posted by oldwave

In my latest trailer, I removed the factory converter and installed a victron multiplus 2000 va (it’s 1500 watts). Now in a Bigfoot the converter is separate, however I also,owned an escape. You would unhook the factory converter from ac and the dc feed from the panel. The multiplus would connect to the battery and the ideally through a victron lynx distributor that also would feed the 12 volt panel through the escape dc side. The output of the multiplus feeds the ac side of the distribution panel. The shore power connects directly to the multiplus. The multiplus has the transfer switch built in. High quality gear, I’m currently running mine with 400 amp hour of lithium. I’m very pleased . If you want details you can pm me and I’ll send some pics. There are also a whole bunch of talented escape owners who have done similar installations. I feel the custom charging profiles of the multiplus is very very good for lithium batteries as well as other chemistries

Thanks for the response!

I'm not sure if I'm able to disconnect the factory converter, seems like it's integral to the AC-DC power center (one of these https://wfcoelectronics.com/product-...f-8900-series/). That being said, the WFCO panel is both fed from the integrated converter as well as the batteries separately. I was thinking of doing it two ways:

1. Remove the battery to DC panel direct feed entirely, and only feed the DC through the AC/Converter. Then I would just cut in the inverter/charger with both shore power and battery feeds.

2. Do that installation listed above, but have a junction box for the DC so that the batteries both feed the inverter as well as the DC main.

[rubicon327]

It looks like you are intending to do a full pass-through (everything is fed through the Victron MultiPlus) which means when off grid any 120V device could theoretically be run via the inverter if you so choose. Depending on how much you want to run you may want to think about the 3000W Victron unit. Battery amp-hours are a major consideration too. Your diagram is flawed in several ways. Check out the attached from AM Solar to help get you straightened out. Top notch group that helped me with a major DIY inverter/charger upgrade. One issue is you need a main input breaker on the 30A shore power feed before any device including an integrated inverter/charger/transfer switch. Also remember the stock WFCO converter/charger takes 120V (shore or generator power) and makes 12V DC to feed instantaneous loads as well as charge the battery. As oldwave said you would take that stock converter/charger (WFCO main board in lower part of the existing power center) completely out of the loop. Your MultiPlus takes care of that functionality now. Your batteries will be charged via the large gauge main DC wires to/from the MultiPlus when you have shore or generator power. Your DC loads (DC fuse board in existing power center) would be fed directly off the battery or a DC buss (not shown in AM Solar diagram). On the AC side your Victron unit will feed the 30A 120V main breaker in your existing power center. If you intend to measure the battery amp-hours with a Victron BMV battery monitor or equivalent remember that everything needs to land on the load side of the shunt for accurate readings. Hope this helps.

https://static1.squarespace.com/stat...T2000KITFP.pdf

[FishTank]

Originally Posted by rubicon327

It looks like you are intending to do a full pass-through (everything is fed through the Victron MultiPlus) which means when off grid any 120V device could theoretically be run via the inverter if you so choose. Depending on how much you want to run you may want to think about the 3000W Victron unit. Battery amp-hours are a major consideration too. Your diagram is flawed in several ways. Check out the attached from AM Solar to help get you straightened out. Top notch group that helped me with a major DIY inverter/charger upgrade. One issue is you need a main input breaker on the 30A shore power feed before any device including an integrated inverter/charger/transfer switch. Also remember the stock WFCO converter/charger takes 120V (shore or generator power) and makes 12V DC to feed instantaneous loads as well as charge the battery. As oldwave said you would take that stock converter/charger (WFCO main board in lower part of the existing power center) completely out of the loop. Your MultiPlus takes care of that functionality now. Your batteries will be charged via the large gauge main DC wires to/from the MultiPlus when you have shore or generator power. Your DC loads (DC fuse board in existing power center) would be fed directly off the battery or a DC buss (not shown in AM Solar diagram). On the AC side your Victron unit will feed the 30A 120V main breaker in your existing power center. If you intend to measure the battery amp-hours with a Victron BMV battery monitor or equivalent remember that everything needs to land on the load side of the shunt for accurate readings. Hope this helps.

https://static1.squarespace.com/stat...T2000KITFP.pdf

Thanks Rubicon!

That diagram is super helpful, I appreciate it, on the AC side it's exactly what I imagined except I missed the 30A breaker (good call). It just clicked why I need to cut out the integrated converter that's already there, ha, don't want the Multiplus and the WFCO panel both trying to charge the batteries. Hopefully that's just pulling a fuse. Looks like I'll need a DC bus to split the feed so I can catch both the DC panel and the Multiplus.

[FishTank]

Originally Posted by oldwave

In my latest trailer, I removed the factory converter and installed a victron multiplus 2000 va (it’s 1500 watts). Now in a Bigfoot the converter is separate, however I also,owned an escape. You would unhook the factory converter from ac and the dc feed from the panel. The multiplus would connect to the battery and the ideally through a victron lynx distributor that also would feed the 12 volt panel through the escape dc side. The output of the multiplus feeds the ac side of the distribution panel. The shore power connects directly to the multiplus. The multiplus has the transfer switch built in. High quality gear, I’m currently running mine with 400 amp hour of lithium. I’m very pleased . If you want details you can pm me and I’ll send some pics. There are also a whole bunch of talented escape owners who have done similar installations. I feel the custom charging profiles of the multiplus is very very good for lithium batteries as well as other chemistries

Thanks Oldwave! I replied, but it looks like the mods have to approve it before it shows up. I'm thinking you're right about the Lynx, or maybe just a junction box.

[dstreight]

Another vote for eliminating the WFCO's transfer switch and let the Victron, or whichever inverter you opt for (assuming it has automatic transfer switch) seamlessly take care of that. I did the same when I added the Xantrex 3000w Freedom X inverter to our 15A a few years ago.

[FishTank]

Originally Posted by dstreight

Another vote for eliminating the WFCO's transfer switch and let the Victron, or whichever inverter you opt for (assuming it has automatic transfer switch) seamlessly take care of that. I did the same when I added the Xantrex 3000w Freedom X inverter to our 15A a few years ago.

Thanks dstreight

After a trip out to the trailer, I think the Lynx distributor mentioned above + an in line 30A breaker + disconnecting the internal converter is the plan of action. Now I'm just left missing if I need to include the current (heh) DC/DC charger into the loop somewhere. Believe this is for the charging from the truck.

[oldwave]

Your drawing looks great
Dc to dc is really only effective with running a dedicated cable from the tow battery bus

[rubicon327]

Originally Posted by FishTank

Thanks Rubicon!

That diagram is super helpful, I appreciate it, on the AC side it's exactly what I imagined except I missed the 30A breaker (good call). It just clicked why I need to cut out the integrated converter that's already there, ha, don't want the Multiplus and the WFCO panel both trying to charge the batteries. Hopefully that's just pulling a fuse. Looks like I'll need a DC bus to split the feed so I can catch both the DC panel and the Multiplus.

You got it now. When on shore power you don’t want both chargers trying to charge the battery but more importantly when off grid we can’t have a loop where the batteries are powering the inverter to run a 120V AC to 12V DC converter/charger to charge the batteries! To disable the stock main board just take the WFCO front panel off and safe off the hot AC (black) wire that probably goes to an existing 15A breaker. Sometimes it is on a utility pigtail with another appliance on the same breaker. If you want to pull it completely out disconnect the ground and neutral too. Then you can pull the DC wiring from the converter off the DC main board too if you like. There are two wires that go to the +VCC and NEG- lugs on the board. At this point the main board would be fully disconnected.

[hugh]

Make sure to double check your wire sizes / fuse capacities. Here's what I have for my 3000VA multiplus:

[dstreight]

We don't rely upon our Sterling 1260 DC-DC charger every outing but it has proven worthy on many occasions. As with all of our modifications, the DC-DC charger is application driven.

Per @oldwave you'll need to run dedicated cables from the engine bay/alternator to the rear bumper instead of relying on the too-small gauge charge wire on the 7-pin plug. I used a weatherproof Anderson Powerpole SB175 on the rear bumper and the trailer tongue side for this connection.

I have a stock alternator on my 2007 Silverado HD2500 and it provides 25amp flow to the LFP battery through the Sterling 1260. Someday, I plan to install a larger capacity Mechman alternator...

[Perry Butler]

We have a 2019 F150 Lariat 3.5 EcoBoost. Before buying our lithiums I asked Ford about ruining our alternator. The service manager laughed and said our alternator was "smart" and won't over charge. The best we've seen using our Victron 712 as a gauge is around 400 watts. After 20 minutes or so it goes down to <200 watts.

In 2020, after our WFCO decided to destroy our AGM's by sending them 20.3 volts, I disconnected our WFCO charger, purchased 270 ah of SiO2 batteries, and have only been charging using our solar since then. From Feb 2020 to August 2021 we only had our 170 watt GoPower roof panel and when needed our 100 watt Renogy panel, and never got below 70% SOC. In 2021 I added three 100 watt panels to the existing 170 watt and didn't need the portable again. We're in our campers around 5 months a year, so plenty of use.

We now have a Bigfoot 25RQ. Last winter we had no problem keeping our two 100ah SOK lithiums full with the 160 watt Carmanah roof panel and our 100 watt portable. Two weeks ago I took the 160 watt panel off (to be given to my son) and installed two 200 watt panels on the roof, so we won't need the portable. However, Terry now has a CPAP and may need a third 200 watt panel. We camped for five nights last week under severe shade and lost about 20 ah's a night without the portable. Our use was about 40-45 ah's, but under severe shade the 400 watts only put 20-25 ah's back into the batteries.

I also removed the Progressive Dynamics charger with Charge Wizard that would easily charge our lithiums when I installed the Hughes Watchdog surge protector that fit perfectly in it's place. Because our solar provides all our needs (I also installed a 2,000 watt Progressive Dynamics inverter/transfer switch) I see no reason to reinstall the PD with Charge Wizard.

Even though I've had a Victron DC-DC sitting in a box for voltage regulation, I see no reason for us to install it. If I didn't trust Ford's alternator I would simply disconnect the wire.

BTW, knowing what I've seen with lithium, I should have purchased another set of SiO2 batteries. However, that's another story.

Food for thought,

Perry