Zamp Solar Pre-Wire Help

[RMNummi]

For the solar Experts: So as I read through the posts I see pretty regular observations of "Don't overload your crappy airstream solar pre-wire".

1. How hard is it to DIY upgrade the existing wires?
2. Given the existing AS wire limitations can I install 4 Zamp Obsidian 90w long panels?
3. Solar Controller is a Victron MPPT 100/30, trailer is a 2017 AS23FBT.
5. Should they be wired Series or Parallel (or both)?

Thanks in advance.

[vanderwielen]

Originally Posted by RMNummi

For the solar Experts: So as I read through the posts I see pretty regular observations of "Don't overload your crappy airstream solar pre-wire".

1. How hard is it to DIY upgrade the existing wires?
2. Given the existing AS wire limitations can I install 4 Zamp Obsidian 90w long panels?
3. Solar Controller is a Victron MPPT 100/30, trailer is a 2017 AS23FBT.
5. Should they be wired Series or Parallel (or both)?

Thanks in advance.

it depends. in 2022, they used #10 wire. Now #8 in 2025. Overloading the factory wire would take a very large array... in parallel. Your 2017 probably has #10 wires, good for 30 amps. With a PV from your array of about 20 volts, you'd source 20 amps to the MPPT. You're fine. Even with larger arrays, creating a series/parallel array can still keep the current down.

[GOUSC]

Originally Posted by vanderwielen

it depends. in 2022, they used #10 wire. Now #8 in 2025. Overloading the factory wire would take a very large array... in parallel. Your 2017 probably has #10 wires, good for 30 amps. With a PV from your array of about 20 volts, you'd source 20 amps to the MPPT. You're fine. Even with larger arrays, creating a series/parallel array can still keep the current down.

I had #8 in my 2018 27 FBT Globtrotter.

[RMNummi]

Having never payed with the old style 3 port Zamp Junction box, iets see if I get this right....Use the Zamp Converter wire (which changes the old Zamp style two prong plug (used at the junction box) to the "new" Zamp style plug used on the Obsidian's) and plug in a new style Zamp splitter then run a separate cable to each panel? i.e. two panels per old style port? Did I get that right?

[uncle_bob]

Hi

The "Zamp connector" is only good for about 20A. The wire is a secondary issue.

If you are going heavy duty, you are better off to replace that connector with one of the Anderson style connectors with a higher current rating.

Since the power is running at "battery level", you have to convert down to 12V. Your panels are running at higher voltage so they will have the same power at a lower current. 300W / 12V = 25A. You typically see "200W" recommendation for hooking into or out of a Zamp connector (also called an SAE connector).

You can get Anderson connectors up into the hundreds of amps range.

Bob

[RMNummi]

Ahh, that makes sense. I’m having Tampa Airstream install the 4 Zamp obsidians this week. I’ll have em upgrade the box at the same time. Muchas Gracias!

[uncle_bob]

Hi

Reading through this again:

Keep in mind, we're talking about the Zamp charging connector that's typically on the battery box (and maybe elsewhere). It's used for hooking up portable panels. They hook to the *output* of a solar converter.

The main wiring for the solar is a different beast. Those connectors are up on the roof.. You only play with them when mounting panels on the roof. They go to the *input* your solar converter. That's all wired permanently and you don't mess with it.

Bob

[GOUSC]

Originally Posted by GOUSC

I had #8 in my 2018 27 FBT Globtrotter.

To clarify, I was referring to the solar pre-wire from the roof to the solar controller. I guess now I don’t know which one the OP was referring to.

[tjdonahoe]

2013 31’ classic. I installed 4 90 watt zamp panels i used double sided tape and silkaflex caulk. Combiner box to the factory wireing victron controller under the couch with a couple breakers …. The controller is wi fi to my phone. It works great

[uncle_bob]

Originally Posted by GOUSC

To clarify, I was referring to the solar pre-wire from the roof to the solar controller. I guess now I don’t know which one the OP was referring to.

Hi

After re-reading things, it seemed to be getting very tangled between the various chunks of wire and connectors associated with the solar ....

Bob

[RMNummi]

Bob, just doing a reset to original query…2017 AS23FBT with factory solar pre-wire and the Zamp 3 port box on the roof. No personal knowledge of 2017 wire gauge from Zamp Port to Victron 130 controller. No previous panels installed by PO. Looking for “your ok with 2 90w Obsidians per side, wired in series, going to your Zamp port w/o any other mods”. Was kinda what I was looking for. I think the answer was “yup, go for it” but wanted to make sure.

[OrangeCrush]

Originally Posted by RMNummi

Bob, just doing a reset to original query…2017 AS23FBT with factory solar pre-wire and the Zamp 3 port box on the roof. No personal knowledge of 2017 wire gauge from Zamp Port to Victron 130 controller. No previous panels installed by PO. Looking for “your ok with 2 90w Obsidians per side, wired in series, going to your Zamp port w/o any other mods”. Was kinda what I was looking for. I think the answer was “yup, go for it” but wanted to make sure.

We were running a similar configuration on our 2017 25FB and the Zamp port failed after 2 years of use. This was with 4 AM Solar 100 watt panels (21.2 VOC) wired in 2S2P running through white Zamp 3 port box using Airtream 10 gauge pre-wire to a Victron controller. Turns out the white Zamp rooftop port has a Bussmann Shortstop 12v rated breaker which can't handle the 40+ volts presented by 2 series panels. Zamp knows this is a problem and has removed it in the newer black 3 port boxes and instead added internal fuses to the Obsidian panels. I have since switched to running 5X100 watt panels all parallel through my own 6 gauge wire drop which works great. Since those Obsidian panels are even higher voltage (24+ VOC) I recommend against running them in any series parallel combination through the Zamp port due to the Shortstop breaker. Instead I would suggest just biting the bullet and doing a proper wire drop for your configuration.

[Wazbro]

I would add that a proper wiring job for rooftop solar includes a disconnect, no matter what Airstream says or does at the factory.

[tjdonahoe]

13. 31’ classic I installed 4 90 watt zamp obsidian panels using the factory# 10 wire to under the front couch. I use a smart victron controller the meter is my phone.. then the wire gors to the buss bar it works very well…nothing wrong with the original wire

[tjdonahoe]

Also i used AM solar combiner box and their pigtails. Each panel is fused

[RMNummi]

I know I should be better at the description…. Basically two panels combined w a Zamp splitter y-cable. Single run to empty left port. Same on right leaving an empty “middle” on the 3 port correct? My view of AS wiring/electrical systems is akin to the original occupants of this country’s first look at a steam engine locomotive…. Oooh magic…. To be fair, I stuck a key in a wall socket when I was a toddler… been paranoid about electricity thereafter.

BTB what theoretically do you think AS would charge to “rewire the roof port to Solar controller? Is it just “unhook the top connection, splice new wire to old then pull like heck from below”. I can already see it as I’m standing there looking down at the pulled apart splice.

[mamorteguy]

I have 2020 FC 25FB that came with 2 Zamp long 90w panels. I added 2 more Zamp 90’s and used the “y” connector to hook up to the 3rd port in the roof top box. So I use all 3 ports. I monitor with a Victron 712, it’s been installed for about 4 years and working great.

[gypsydad]

Originally Posted by OrangeCrush

We were running a similar configuration on our 2017 25FB and the Zamp port failed after 2 years of use. This was with 4 AM Solar 100 watt panels (21.2 VOC) wired in 2S2P running through white Zamp 3 port box using Airtream 10 gauge pre-wire to a Victron controller. Turns out the white Zamp rooftop port has a Bussmann Shortstop 12v rated breaker which can't handle the 40+ volts presented by 2 series panels. Zamp knows this is a problem and has removed it in the newer black 3 port boxes and instead added internal fuses to the Obsidian panels. I have since switched to running 5X100 watt panels all parallel through my own 6 gauge wire drop which works great. Since those Obsidian panels are even higher voltage (24+ VOC) I recommend against running them in any series parallel combination through the Zamp port due to the Shortstop breaker. Instead I would suggest just biting the bullet and doing a proper wire drop for your configuration.

Following, but have not purchased solar...yet. When I called AS last summer while installing my LiTime batteries, inquiring about adding (4) 100W solar panels wired to the plug on the roof, I was told by the tech I spoke with, the wiring to that plug is meant for 300W max. (?) He said I would have to re-wire if I added more panels? Anyway, think 300W for our use would be fine, but I have not pursued yet. Renogy panels on Amazon with hardware and wiring are pretty inexpensive these days....thinking I will go that route. Local AS dealer wants 3 times the price for same panels on Amazon; not counting installation!

I was reading on FB RV site about "new" lighter weight, solar panels with "smart" diodes which turn on/off or "channel" power thru cells with best sun access? Anyone checked into this technology or have comments on this? Sounds very interesting...assume lots of $$ likely. I could not find while browsing the net.

[uncle_bob]

Originally Posted by RMNummi

.....

BTB what theoretically do you think AS would charge to “rewire the roof port to Solar controller? Is it just “unhook the top connection, splice new wire to old then pull like heck from below”. I can already see it as I’m standing there looking down at the pulled apart splice.

Hi

As a guess based on other stuff AS has done for us at JC:

Parts cost would not be to insane. Labor cost is the issue. When they work "on the roof" it's quite an operation. Their safety rules have a significant impact. Their labor rate per hour is no better / no worse than a lot of places these days.

I'd bet half a bottle of warm beer on it being in the $2K to $3K range. Could it be twice that? Maybe it could be. Running wires through the walls (done properly) might be insane. I very much doubt it would be less.

Crazy !!!

Bob

[Wazbro]

Originally Posted by RMNummi

BTB what theoretically do you think AS would charge to “rewire the roof port to Solar controller? Is it just “unhook the top connection, splice new wire to old then pull like heck from below”. I can already see it as I’m standing there looking down at the pulled apart splice.

Airstream doesn't make it easy to "splice new wire to old then pull like heck from below”. They install the wires, spray the inside of the outer skin and the wires with adhesive then put in the insulation gluing it all together.
Will that adhesive stop you from being able to pull wire that way in a straight line from roof down to the floor? Maybe.
Will it stop you from pulling it down from the roof and making a 90° turn to go through a few ribs before it comes out? Probably.
Would Airstream charge you thousands because to do it right they "need" to remove and reinstall interior skins? Could be.