Magnitude SV34 Inverter Upgrade and Rewiring for Whole House Inverter Power

[Judge]

Last year I did a LiFePO4 upgrade using (4) BigBattery 170Ah batteries. This year I decided to upgrade the inverter and do some rewiring so I could use the inverter for any circuit.... within reason. One goal is to also be able to run one of the Coleman Mach 3 A/C units as well…. and without installing a SoftStart.

I decided to stick with Xantrex since I already had the Bluetooth Remote Control Panel for the Freedom X 2000. I purchased the Xantrex 3000W / 50A Freedom XC PRO Inverter / Charger. I like the configurability and charging for the LiFePO4 batteries plus the additional power and performance it delivers. It is also firmware upgradeable as well.

Based on the performance specs I found for the Coleman Mach 3, this inverter should have plenty of power to start and run one of the A/C’s with room to spare.

I also decide to wire the inverter output properly with a sub-panel since Thor ignores Xantrex's recommendation for using a sub-panel for the output feed. Thor uses a 15A breaker in the WFCO Power Center to supply AC power to the Inverter but once on inverter power there is no circuit breaker between the inverter and the rest of the circuit.

I opted for the Square D 70 Amp 2-Spaces 4-Circuit Main Lug Load Center so I could use a single 15A breaker for the circuit that Thor wired for the inverter to provide power to the two fridges and a few other outlets. I also decided I would add a 20A Tandem Breaker so I could back-feed the WFCO Power Center when I wanted the inverter to supply power to the other circuits.

I posted a pic of my sub-panel, new inverter and the Coleman Mach 3 A/C specs.

[Judge]

The inverter output is capable of 50A but I don’t plan to need that much current draw so I used some 10AWG THHN/THWN wire and some LiquidTite flexible conduit for the inverter output that I had in the shop. This will be good for 40A and it’s only about a five foot run from the Inverter to where I was going to place the sub-panel.

Thor ran 14/2 Romex for the inverter output from one of the storage bins through the floor under one of the dinette seats. I decided to install the subpanel under that dinette seat where the 4th of my four LiFePO4 batteries are located so I could use the existing holes cut in the floor.

I was able to easily run the new output wiring through the floor and wired into the new sub-panel. I added a 15A breaker and connected the 14/2 Romex Thor ran to supply inverter power to the two fridges and TV. This circuit now has its own breaker as recommended by Xantrex.

[Judge]

I was hoping to run some new wire through a hole in the bathroom wall under the dinette seat over to the bedroom and the electronics bay but there were too many obstacles with minimal access. After looking under the coach and looking at my options, I decided I could get the new wire through the passenger side frame rail where the hydraulic hoses were run using a feeder line.

I decided to go with some 12/4 SOOW through the frame rail to the back of then coach and up through an existing hole where all of the other wiring was run. With a little help from the wife we were able to get the SOOW run through the frame rail without much difficulty. It was about a 26 foot run and good for up to 20A. I was able to use several zip ties to secure the SOOW against the frame rail and keep it away from any bolts, sharp edges, moving parts, etc.

I then fished one end of the SOOW up through an existing wiring hole in the bottom of the bin and then up through the hole in the floor under the dinette seat. I used a 20A Tandem Breaker to supply the two hot wires that I would need to feed each side of the busbar in the main breaker panel. I used WAGO connectors and some 12AWG Romex to connect the breakers to the SOOW wired in the sub-panel.

Next I fished the other end of the SOOW wire through the hole in the floor under the bed and into the electronics bay. I used a junction box, some WAGO connectors and a section of 12/4 UF-B to get to the back of the WFCO Power Center.

[Judge]

I had two open breaker positions in my Power Center (one for Line 1 and one for Line 2) so I added two 20A breakers that would act as the inverter feed into the Power Center. After connecting the ground and neutral to the busbars, I ran each of the hot wires to its respective 20A breaker. These breakers will always be off until I want to use the inverter to power a circuit.

When I want to use the inverter to power other circuits besides the fridge, I will turn all breakers off in the Power Center (including the 50A main breaker so it does not backfeed to my hardwired EMS and the ATS). Then I will turn on either the Line 1 or Line 2 20A breaker to supply power to the busbar for the circuit that I want powered and then turn on the breaker for that specific circuit.

After I got all of my wiring done and secured, I decided I would only turn on breakers for some outlets on Line 1 and Line 2 so I could use my tester to verify the wiring and grounds were all good and then use my meter to verify that the voltages were what and where they should be!

Once I verified the wiring was all good for Line 1 and Line 2 I tried the bedroom TV, which was not on the original inverter circuit. The TV worked great so next it was time for the big test….. running one of the A/C units.

[Judge]

I decided to try the bedroom A/C unit because that would be the one we run at night if we don’t have shore power or can’t run the generator. I decided I would just turn on the fan first to make sure that worked ok and then set it for cooling to ease into the inverter power. I turned on the Line 2 20A breaker and then the breaker for the bedroom A/C.

I then used the FireFly app to turn on the fan…. I hear the relay click….. but no fan…. nothing. I also had the Xantrex and Victron apps running and there were no signs there was any demand being placed on the inverter. I triple checked my wiring and got my meter out and the voltage was where it was supposed to be.

Now this is a heavy duty inverter and it should easily power up the A/C blower motor so I started checking schematics and scratching my head. Knowing everything was correct on my end, I decided to pull out my wife’s hair dryer. I turned the breaker on for one of the outlets and sure enough… it powers up on the high setting and was drawing about 1400 watts as I would expect.

[Judge]

So now I’m really stumped….. and then I remember that I forgot Rule #1……





Rule #1…. never….. never…… and I repeat……never trust anything Thor does!!!!






It turns out that one of the Thor Geniuses labeled the breakers incorrectly! The breaker labeled REAR A/C was actually the breaker for the front A/C and the breaker labeled FRONT A/C was actually the breaker for the bedroom A/C.

Once I figured out Thor’s curve ball, I reconfigured the breakers and….. Houston…. we have inverter powered A/C!!!

The startup on the inverter was very smooth and quiet…. just like when its connected to shore power. It fired up so easily that I won’t need to worry about installing a SoftStart.

According to the Xantrex app it started off at about 1000 watts, which was right around the Mach 3 spec. I ran it for about 30 minutes and it was hanging around 1300 watts on the high fan setting. The outside air temp was about 80 and the inside temp was 76 when I turned it on. The A/C wasn't even using half of the inverter capacity so that was good to see as well.

The batteries were about 97% SOC when I started and they were down to about 92% when I decided to shut down the A/C. According to the Victron app, I had about 5 hours battery power left with all the lights on in the coach and the A/C running.

Of course, I created some new labels for the A/C breakers to fix Thor's curveball on the breaker labeling.

[Judge]

I think the LiFePO4’s and the new inverter will do the job I intended nicely. When we are off the grid and can't use the generator, we can use the kitchen outlets for the coffee maker now instead of running an extension cord from one of the original inverter outlets. We can also use the bedroom TV. I haven't tried the microwave but I am sure the inverter should be able to handle it along with being able to power the cooktop as well.

And if we need A/C at night, we can close the door to the bedroom and it will keep the cold air in at night so the A/C won’t have to run as long or as often.

I’ll need to do some more real world testing to determine what reality will be in terms of battery life. The two fridges will typically be running as well but if we start with them cold they don’t draw too much power. I think 680Ah should be about enough to do what we need for the times we're off the grid... but I do have room to add one more 170Ah battery if I want to take it up to 850Ah.

Anyway…. I’m pretty happy with the way the inverter upgrade turned out as well as the BigBattery LiFePO4's I installed last year. If it weren’t for Thor mislabeling the A/C breakers, I would have had more time in planning and crawling around under the coach than I did getting everything installed and wired up.

[Pillbox]

Where do insert my credit card for the lesson.
Nice job sir.
Terry

[Judge]

Thanks Terry!


There is another advantage with the new inverter / charger. Much more efficient and rapid battery charging.

When I upgraded the converter / charger last year to the Progressive Dynamics 60A PD9160ALV for the LiFePO4's, I was never get much more than 30 - 40 amps when Bulk Charging. It was not so much the device's fault but more the very long cable run and the undersized cable between the batteries and the converter / charger that Thor used.

Last year when I did the LiFePO4 upgrade, I fixed all of Thor's inverter and battery compartment wiring mess. There were several excess feet of cabling for the inverter.... much longer than the Xantrex spec. I did a much shorter run with much better cables to improve the inverter performance and in case I decided to upgrade the inverter at some point. But it was going to be too much money and effort to upgrade the cables to the converter / charger. I'm glad at this point I decided not to go that route since I did move to an inverter / charger.

The Xantrex Freedom XC PRO 3000W can be configured for up to 150A charging. My BigBattery LiFePO4's can take a maximum of 175A. I configured the charger for 125A and I am getting over 85A when Bulk Charging. They were only down to about 90% but I could already tell they charge much more quickly than they did with the converter / charger.

[Judge]

And one other advantage of moving to the inverter / charger...... I don't have to rewire the battery disconnect relay so the main power light for the Use / Store switch is only ON when the switch is actually in the USE position..... the way it should have been from the factory....... which consequently would end the million posts from people about their batteries not charging.

I'm not removing the converter / charger. I just turned the breaker off. I figured I would leave it onboard in case the inverter / charger ever fails and I have a backup way to get then house batteries recharged besides solar.

Anyway.... now that the converter is permanently powered off, the main power light is only on when the batteries are actually connected to the house when in the USE position. It will not light up now when there is shore power but the Use / Store switch is in the STORE position.... as it should be.

Also, since the batteries are hooked directly to the inverter / charger, they will continue to charge and be maintained even when on shore power even if the Use / Store switch is in the STORE position..... so long as the inverter / charger is switched on.

[lwmcguir]

Interesting project and excellent detail

Very handy for boondocking for sure

Excellent work per photos and details

Glad it turned out as planned and thanks for sharing

[Fullabunk]

Great job and description was understandable. Congratulations

[LarryD]

Judge, you are living the dream! I cant wait to do the same just need to find the time. Question, do you think the stock inverter could handle one AC? I just got my coach back to the farm in NY and I plan to move one AC over first to see if it'll work. Thoughts?

[ducksface]

https://www.amazon.com/Xantrex-815-3...%2C1306&sr=8-8

I have this 3000/6000w xantrex unit and it started the ac just fine but I didn't have the battery storage amps to do anything.
The ac jacked with it all a bit so I took the ac off of the whole house inverter for now. When I get the big batteries, I'll reattach it. The batteries would drop real low real fast kicking in the low voltage warning and killing my entire coach until it all caught up again. Judges batteries are the only thing that makes a whole house system work.

These units also piggyback into 6,000w and double the charging.
And
It will add voltage to pedestal low voltage by tapping the batteries for the 108v to 112v difference.

Mine doesn't do Bluetooth or firmware upgrades.
It can, but it's a $400 add-on module.

I'm happy with xantrex stuff.

[Judge]

Originally Posted by LarryD

Judge, you are living the dream! I cant wait to do the same just need to find the time. Question, do you think the stock inverter could handle one AC? I just got my coach back to the farm in NY and I plan to move one AC over first to see if it'll work. Thoughts?

Thanks Larry!

I think you might get away with the stock inverter. If not, you could try and install a SoftStart in the A/C you want to use.

I have my A/C’s sealed with insulation and didn’t want to open them to install a SoftStart. Plus I wanted a little more power to run multiple items at one time now that I have 680Ah of LIFePO4.

Speaking of inverters….. I’m in the Virgin Islands boating around the islands on a 51’ Power Cat. The specs said it should have a 2000W Inveter but surprisingly it does not. The fridges are 120V / 12V so I guess they didn’t install an inverter. It does have 3 A/C units so the generator is getting a serious workout anyway. It also rigged with two 30A shore power cords.

[LarryD]

Originally Posted by Judge

Thanks Larry!

I think you might get away with the stock inverter. If not, you could try and install a SoftStart in the A/C you want to use.

I have my A/C’s sealed with insulation and didn’t want to open them to install a SoftStart. Plus I wanted a little more power to run multiple items at one time now that I have 680Ah of LIFePO4.

Speaking of inverters….. I’m in the Virgin Islands boating around the islands on a 51’ Power Cat. The specs said it should have a 2000W Inveter but surprisingly it does not. The fridges are 120V / 12V so I guess they didn’t install an inverter. It does have 3 A/C units so the generator is getting a serious workout anyway. It also rigged with two 30A shore power cords.

Judge, when I die I want to come back as you You sailing that cat solo or is it chartered? There are a couple squids on here, Im sure you could talk them into helping Enjoy man!

[Judge]

Originally Posted by LarryD

Judge, when I die I want to come back as you You sailing that cat solo or is it chartered? There are a couple squids on here, Im sure you could talk them into helping Enjoy man!

LOL!!!!!

Before COVID we booked the US Boat Flotilla with another couple to cruise the British Virgin Islands through the Moorings. Well that got postponed for two years.

There is a lead boat and then there are 4 Power Cat and a Sailing Cat in the group.

I was ok with reserving the 43’ Power Cat since it was only four of us but our friends wanted the 51’. We were piloting it ourselves so I thought the 43’ would be easier since me and the other guy have only had 30’ boats on lakes and rivers.

This 51’ is a beast! It’s a lot of boat….. it takes all four of us to do mooring balls or dock. It’s a lot of work and really too much boat at the end of the day.

It is cool…. the technology is pretty amazing. The wind was a little gusty and the seas were 3 - 4’ today. I engaged the Auto Pilot and it was moving the rudders 12 - 15 degrees to hold our heading. Without the Auto Pilot it would have been a pain to steer for 2 hours with continually moving the wheel back and forth.

I’ve never lived on a boat for a week so this is a new experience for us. We’re having a good time…. but I think I like being in my Magnitude better!

[macdaddy1111]

Very Impressive!

Need a month say in NC! ha

[Judge]

Originally Posted by macdaddy1111

Very Impressive!

Need a month say in NC! ha

I’ll be over when I get back to shore!

[Chance]

Nice job with inverter/charger upgrade Judge.

As your project highlights, it would be so much easier and cheaper if manufacturers built it that way from start. It’s been many years coming but technology has finally become affordable enough that primary power from inverter is a viable option, relegating generator to secondary power mostly to charge batteries and power air conditioners when needed for extended periods. Pretty much everything else in RV can be powered more conveniently from inverter.

Thanks again for update.