RV Steve
New Member
This is my first post here. I have been reading others posts for a couple months. I am a full time RV'R since 2015 and purchased my second trailer, a used 2021 Outdoors RV 280RKS, May 2023. My first trailer had 3 x 100 watt Renogy monocrystalline panels with a Schneider (Xantrex) C40 controller. I have been at an RV park in Fairplay CO since purchasing my second trailer which has bought me time to put together a nice solar system. As I've seen good deals I've purchased some components. I have 12 x 100 watt monocrystalline Renogy panels with tilt mounts; my roof is curved so putting these up will require improvising. I bought 2 Victron Smart Solar 150/60 TR controllers and a Smart Shunt. I need to purchase a Victron 12/3,000/120 MultiPlus, maybe a Smart Dongle, LiFePO4 batteries (4x Redodo 200AH Plus), wiring, fusing, and get started installing. My trailer has a Zamp ZS-3B three SAE port roof cap installed with 8 gauge wiring to the overhead front bedroom cabinet (factory assumed controller location) and 8 gauge wire from there to the front triangle battery location. The roof cap combines all 3 SAE ports in parallel and is limited to 30 Amps total (20 amps max at any SAE port) and 300 Volts.
1. I would like to wire my panels in two groups of six in 2S3P down each side of my trailer. This would put me just over the amperage limit of my roof cap. My panels are 24.3 volts Voc and 5.21 amps Isc. Taking into account temperature coefficient the Isc would be 5.34025 at -13 degrees Fahrenheit; in Colorado at 10,000 feet; it could happen during the winter. Wiring 2S3P would give me 16.02075 amps through 2 of the 3 SAE ports for a total of 32.0415 amps just over the 30 amp limit. Is that enough over to be a problem? I called Zamp and was told the SAE ports are wired together using short pieces of 10 gauge wire (3"or less) and then connect to 8 gauge wire that goes to the controller. They didn't employ a busbar to combine the 3 SAE ports in this model roof port but did in later models. They thought that at 32 amps I could experience a little voltage loss but no safety issues.
2. I am planning on using MC4 branch connectors to connect the series panels in parallel. Is there any reason why that wouldn't work? Is it better to run wire from each series connected set of panels to a busbar in a combiner box? Seems to me this would just use more wire.
3. Can I feed two charge controllers from my existing roof port which has one 8 gauge output? I was thinking of running the 8 gauge wire from the roof port to power posts where I could hook up feeds to each of the controllers. Or should I remove the existing roof cap and replace it with a combiner box like the one AM Solar makes?
4. I was looking at the service manual for the MultiPlus 12/3,000/120 and it recommends two 1/0 gauge positive and negative connections to the battery bank. Is there any reason why one 4/0 gauge connection wouldn't work? The latter would be simpler for fusing. FYI my trailer has a 30 Amp 120 volt AC electrical system.
Thanks in advance for your advice and input!
1. I would like to wire my panels in two groups of six in 2S3P down each side of my trailer. This would put me just over the amperage limit of my roof cap. My panels are 24.3 volts Voc and 5.21 amps Isc. Taking into account temperature coefficient the Isc would be 5.34025 at -13 degrees Fahrenheit; in Colorado at 10,000 feet; it could happen during the winter. Wiring 2S3P would give me 16.02075 amps through 2 of the 3 SAE ports for a total of 32.0415 amps just over the 30 amp limit. Is that enough over to be a problem? I called Zamp and was told the SAE ports are wired together using short pieces of 10 gauge wire (3"or less) and then connect to 8 gauge wire that goes to the controller. They didn't employ a busbar to combine the 3 SAE ports in this model roof port but did in later models. They thought that at 32 amps I could experience a little voltage loss but no safety issues.
2. I am planning on using MC4 branch connectors to connect the series panels in parallel. Is there any reason why that wouldn't work? Is it better to run wire from each series connected set of panels to a busbar in a combiner box? Seems to me this would just use more wire.
3. Can I feed two charge controllers from my existing roof port which has one 8 gauge output? I was thinking of running the 8 gauge wire from the roof port to power posts where I could hook up feeds to each of the controllers. Or should I remove the existing roof cap and replace it with a combiner box like the one AM Solar makes?
4. I was looking at the service manual for the MultiPlus 12/3,000/120 and it recommends two 1/0 gauge positive and negative connections to the battery bank. Is there any reason why one 4/0 gauge connection wouldn't work? The latter would be simpler for fusing. FYI my trailer has a 30 Amp 120 volt AC electrical system.
Thanks in advance for your advice and input!