4000 Watt Holiday Rambler Class A Build

[Off Gridin' It]

Just wanted to post some pics of my latest build. A 2004 Holiday Rambler Neptune Class A
Here are the details.

4000 watt solar array
Custom aluminum solar racking with steel coated safety tension cables.
(2) EG4 - 100ah 48 volt rack mounted batteries. 10240 wh capacity
Growatt SPF 5000 US
Solar Edge auto transformer
240 volt split phase AC output
(2) Victron 48/12 volt step down converters for a total of 60 amps available for slides and leveling jacks.
Sterling 12/48 volt DC to DC charger
Victron BMV-712 Battery Monitor

This will run everything in the RV including both AC units at the same time.
It was built to be able to easily expand the battery bank with 2 more EG4 batteries.
I also included some screenshots from the VictronConnect app.
During the array build I also cleaned and repaired any old roof damage that looked like may later be compromised.
This was a fun and tough build!

 

[x98myers7]

dang! 4kw on a motorhome!

I'd like to know more about the rack system. obviously placing panels above all the accessories has many advantages, but i would imagine securing it for highway speeds was challenging. can you explain more about the cable system?

also, how's the added wind noise? MHs are crazy loud to begin with, so.... i'm betting not much added.

 

[MrThisIsME]

Very nice install. Loads of power!

You have good luck with the Sterling 12 - 48v. I have installed three so far and to be honest less than impressed with user interface as well as output. With there was something else in this price range.

 

[Off Gridin' It]

Very nice install. Loads of power!

You have good luck with the Sterling 12 - 48v. I have installed three so far and to be honest less than impressed with user interface as well as output. With there was something else in this price range.

You're right!! I was also very unimpressed with the Sterling. I don't think I will use one again. In fact on a build this large I probably will skip the DC to DC charger completely. I have heard rumors that Victron is working on a 12 volt to 48 volt DC/DC charger although I can't find and real confirmation of that.

 

[MrThisIsME]

You're right!! I was also very unimpressed with the Sterling. I don't think I will use one again. In fact on a build this large I probably will skip the DC to DC charger completely. I have heard rumors that Victron is working on a 12 volt to 48 volt DC/DC charger although I can't find and real confirmation of that.

Aside from the user interface being some type of reject from the 70s, the output is what troubles me the most. 80 to 90% of the time it is spitting out about 7 amps for me. Far cry from the 17.5 amps it is rated. Granted it gets to 17.5 amps every once in a while but not for long before it drops down the 7 again. I think it is derating itself for heat. I even set it up with the ignition feed, no difference.

A Victron unit the same price range and amps as the Sterling would have me chucking it in a heartbeat.

 

[Off Gridin' It]

dang! 4kw on a motorhome!

I'd like to know more about the rack system. obviously placing panels above all the accessories has many advantages, but i would imagine securing it for highway speeds was challenging. can you explain more about the cable system?

also, how's the added wind noise? MHs are crazy loud to begin with, so.... i'm betting not much added.

The racking is all aluminum strut channel. It is very strong and has a weight capacity far over the weight of the panels. Each 10ft strut has a 330 lbs weight capacity.
The racking runs along the length of the RV roof and is secured with VHB tape, Lag bolts and dicor lap sealant on top of each bolt so it absolutely can't move.

The panels themselves are mounted with end clamps and mid clamps. They are secured with heavy stainless steel Allan bolts into cone nuts. this makes them easy to remove for service to the roof. There are cross cables from side to side to add rigidity and strength. They are tentioned to provide that extra strength. There is also a cable that runs from front to back though "U" brackets in the panels to retain them and keep them on the roof should one come loose. (Although I have never had one come loose). Safety is very important so this protects other drivers.

As for wind noise, my client reported back that it is now much quieter then it was before the install. She said before she could hear the wind noise and now she can't. She also said the RV runs more smoothly than it did when going down the road.

 

[Off Gridin' It]

Aside from the user interface being some type of reject from the 70s, the output is what troubles me the most. 80 to 90% of the time it is spitting out about 7 amps for me. Far cry from the 17.5 amps it is rated. Granted it gets to 17.5 amps every once in a while but not for long before it drops down the 7 again. I think it is derating itself for heat. I even set it up with the ignition feed, no difference.

A Victron unit the same price range and amps as the Sterling would have me chucking it in a heartbeat.

Yes! 7 amps! That is about what I was getting also which didn't even overcome the parasitic drain of the RV. I use the 12/12 and 12/24 Victron DC to DC chargers for the 12 volt and 24 volt systems and it always works flawlessly.

I no longer use victron inverters because I have found that Growatt, EG4 and MPP Solar have just as good quality but I can save my customers a ton of money so they can have a bigger system. But I always use some Victron components. Plus the all in one system saves space.

 

[MrThisIsME]

The racking is all aluminum strut channel.

Are the strut brackets and such aluminum? Where did you source? I like Unistrut, but the bracket price is the catch.

 

[Off Gridin' It]

Aside from the user interface being some type of reject from the 70s, the output is what troubles me the most. 80 to 90% of the time it is spitting out about 7 amps for me. Far cry from the 17.5 amps it is rated. Granted it gets to 17.5 amps every once in a while but not for long before it drops down the 7 again. I think it is derating itself for heat. I even set it up with the ignition feed, no difference.

A Victron unit the same price range and amps as the Sterling would have me chucking it in a heartbeat.

Reject from the 70's!! LOL. Thats good! Yeah it doesn't have the most modern look. It would be better if it had bluetooth configuration capability.

 

[MrThisIsME]

Yes! 7 amps! That is about what I was getting also which didn't even overcome the parasitic drain of the RV. I use the 12/12 and 12/24 Victron DC to DC chargers for the 12 volt and 24 volt systems and it always works flawlessly.

Aside from the unit being defective by design and only really providing 7amps or so is the fact that I provide the proper size cable for the advertised amps, and it never really shows. I used them in 5th wheels from truck to trailer through an Anderson and the cable lengths are significant.

Same with the Victron 48v-12v. I use two of them as well. Would be nice if Victron came out with a 60 amp unit.

 

[Off Gridin' It]

Are the strut brackets and such aluminum? Where did you source? I like Unistrut, but the bracket price is the catch.

The brackets are all galvanized which is still very resistant to rust but they don't have any of the brackets available in stainless. Or at least I haven't found them yet if they do.

I buy all the aluminum strut from Grainger. They have the best deal for 10ft length. I couldn't find that length on Amazon. The brackets are from Menards and Amazon. The cost on the entire racking system was about $2000 but that was a very large rack at 35 feet.

I was thinking about doing standoffs to cut down on the aluminum strut but I could only find them as tall as 8 inches and I needed 13 inches of height for this project. But this route was stronger anyway so I believe in the end it was the best option.

 

[MrThisIsME]

I buy all the aluminum strut from Grainger.

I think I do similar to you here.
I get mine from Zoro. Keep in mind if you order more than $150 it is free shipping as well. I get the 10' lengths in 2 or three days by freight. Amazing.

Results for "strut channel"

Zoro Tools Industrial Supplies

www.zoro.com

 

[Off Gridin' It]

I think I do similar to you here.
I get mine from Zoro. Keep in mind if you order more than $150 it is free shipping as well. I get the 10' lengths in 2 or three days by freight. Amazing.

Results for "strut channel"

Zoro Tools Industrial Supplies

www.zoro.com

Thats great! It is always good to have more sources since materials are so much harder to get since Covid. I like Grainger because they have warehouses all over and they have one 30 min from me so I can pick up the supplies and don't have shipping which saves a bunch.

 

[MrThisIsME]

Thats great! It is always good to have more sources since materials are so much harder to get since Covid. I like Grainger because they have warehouses all over and they have one 30 min from me so I can pick up the supplies and don't have shipping which saves a bunch.

Grainger is like 1 hour from me and it seems they always have to order it in. No difference in timing. Plus Zoro seems to be cheaper.

Do like your design. Hope you do not mind if I copy some of your elements.

I only did one install with VHB, but when I did, I used the solid channel (with no oval holes). Thinking more surface area for the tape to stick to . I also use solid channel all the time now as it ensures hitting a rafter each time.

I do the same with Dicor as you do. One thing an RV tech taught me, use an inch or so of butyl tape one each bolt hole from the channel to the roof. Once I used it, will never not. Works great to seal up and I consider the Dicor over the top, just insurance. You can see it squasing out in the pic below.

 

[Off Gridin' It]

Grainger is like 1 hour from me and it seems they always have to order it in. No difference in timing. Plus Zoro seems to be cheaper.

Do like your design. Hope you do not mind if I copy some of your elements.

I only did one install with VHB, but when I did, I used the solid channel (with no oval holes). Thinking more surface area for the tape to stick to . I also use solid channel all the time now as it ensures hitting a rafter each time.

I do the same with Dicor as you do. One thing an RV tech taught me, use an inch or so of butyl tape one each bolt hole from the channel to the roof. Once I used it, will never not. Works great to seal up and I consider the Dicor over the top, just insurance. You can see it squasing out in the pic below.

View attachment 108643

You can never go wrong with being over protective about water proofing. I run the VHB tape down the entire length of the channel and every 2 ft I leave a 1 inch space to allow for water to run under the channel so it won't collect. Using mounting like we do makes changes later on so much easer. Especially if you need to replace a panel for whatever reason.

 

[x98myers7]

As for wind noise, my client reported back that it is now much quieter then it was before the install. She said before she could hear the wind noise and now she can't. She also said the RV runs more smoothly than it did when going down the road.

excellent. i'm betting the two panel fairing on the front is the key. some aluminum sheeting along the sides to "box" in the entire structure would help even more... and be pretty cheap. but, if it ain't broke... don't fix it. Love it. I wish my wife and I boondocked more so I could justify this kind of project.

 

[chrisski]

That is nice. The client was lucky to find someone to put that together for them.

Where is the Growatt located? Not sure if its inside or in a pass through area.

 

[Off Gridin' It]

excellent. i'm betting the two panel fairing on the front is the key. some aluminum sheeting along the sides to "box" in the entire structure would help even more... and be pretty cheap. but, if it ain't broke... don't fix it. Love it. I wish my wife and I boondocked more so I could justify this kind of project.

Yeah the 4000 watt RV is for someone that lives full time so it is easy to justify for her. My RV has 1700 watts and 6000wh battery capacity. I can run my air for 6 to 8 hours but that is running the bank pretty low by the end of that.

 

[ArtDeco]

I would like to know what electric appliances are in the RV. I assume full compressor refrigerator, microwave, and induction cooktop? Maybe a clothes washer and dryer ? Electric heaters or propane?

 

[Off Gridin' It]

I would like to know what electric appliances are in the RV. I assume full compressor refrigerator, microwave, and induction cooktop? Maybe a clothes washer and dryer ? Electric heaters or propane?

There is no washer/dryer however the system can support that.
The refrigerator is an LP/Electric fridge and it is a compressor type refrigerator.
She runs it on AC power during the day and switches too propane at night so she can go a long time between filling the propane.
It has a microwave and propane stove. (She prefers cooking with gas).
Propane heat but it does have an electric component as it runs a fan to move heat.

I did load tests after the system was up and running and was able to run both AC units, Microwave and refrigerator all at once and I still couldn't overload the inverter. It just kept running.