MultiPlus Installation Questions

[RV Steve]

I purchased a open box Victron MultiPlus 12/3000/120-50 120V from Inverter'R'US and have downloaded (and read some of) the Service Manual, Owner's Manual, and Wiring Unlimited. I have 4 x 200 AH LiFePO4 batteries; Feence brand with JBD bluetooth BMS. 12 x 100 watt panels (2 arrays 2S3P) run through two Smart Solar 150/60 - TR controllers. My installation is going slowly due to work constraints. I have a SmartShunt, MK3 to USB-C adapter and a Smart Dongle. I'm hoping my Cables To Go brand UTP Cat5E cables will work in lieu of the expensive Victron cable? If not I need to buy a Victron cable. My 2021 Outdoors RV 280RKS trailer has 30 amp service. The 30 amp shore power inlet is a Furrion IM-F30ITX-V1 and the power converter is a Progressive Dynamics PD4060K. I will continue to use the PD4060K as my 120 volt AC and 12 volt DC panels and take the converter off line. The 30 amp line in is 10 AWG Romex. I'm assuming the PD4060K will accept up to 8 AWG Romex since the manual provides torque specs for 8 AWG as well as 10-14 AWG; it doesn't provide specs for 6 AWG . The shore power inlet will accept 6 AWG, I think; I called Furrion and they said they "think" it will. Some people have posted regarding having issues connecting smaller Romex to the MultiPlus 3000. Some folded it over and some spliced to thicker wire. Power Assist sounds nice but I only want 30 amps. Can I configure the MultiPlus to put out no more than 30 amps? If not I could turn Power Assist off. Correct? Bottom line I would rather limit my 120 volt power to 30 amps to simplify my 120 volt wiring. 8 AWG Romex is stranded and rated to 40 amps. It would fit my converter and shore power inlet. Victron recommends 6 AWG stranded for the AC in and out 1. I'm thinking of using 8 AWG Romex for both which would be oversized for 30 amp max configuration but is stranded unlike the 10 AWG Romex which is solid. I also plan on hooking up only AC Out 1 since my loads won't exceed the inverter output. No sub panel. I know not to run the microwave, water heater, and air conditioner all at the same time and can turn those breakers off when they're not needed.

I have 3 possible 120 volt power sources. Shore power from a 30 amp pedestal that has a breaker. A 2000 watt Champion inverter generator rated 2000 surge and 1700 running. A 4000 watt Wen inverter generator rated 4000 surge and 3500 running. I am in Colorado year round now but eventually summer only and winter in AZ. I will be at high altitude most of the time so my generator outputs will be lower. I don't plan on running generators unless absolutely necessary or using shore power.

A 30 amp breaker in between my shore power inlet and the MultiPlus would be good but I am having trouble finding a small set up. It seems that since my generators won't be exceeding 30 amps and shore power hook ups usually have a 30 amp breaker that I could forego a 30 amp breaker in between the shore power inlet and MultiPlus. Would that be OK? Has anyone else gone that route? Otherwise I have a Midwest Electric 30 Amp AC disconnect I could use or Square D makes a couple 30 amp load centers that would work. Carling Technologies also makes panel mount 30 amp breakers. Those are the best options I've found. I'm open to suggestions that are hopefully small and affordable.

I'm wiring the DC to the MultiPlus with 2 x 1/0 as recommended in the service manual with a 400 Amp Class T fuse in between the positive connection bus bar and the MultiPlus. I will run a ground from the negative load bus bar to the chassis. From what I've read it sounds like the chassis grounds for the controllers and the MultiPlus should run to the negative load busbar which is grounded to the chassis. Correct? I'm not certain what size wire is needed for the controller and MultiPlus chassis grounds. For the negative busbar ground I understand it would need to be wire that can handle 400 amps which is 4/0. I think ABYC frowns on using 2 x 1/0 since each conductor should be able to handle the 400 amps. I believe Victron is OK with the wire being 1 size down which would be 3/0. Is that correct? I have posted about this connection before. My trailer has 3 ground connections. One at the front triangle battery location for the negative battery terminal. One at the factory negative 12 volt load busbar located in a underbelly compartment right behind the front triangle. Another at the PD4060 power center near the middle of the trailer. I plan on disconnecting the existing battery negative ground connection, running my new ground wire from the new negative busbar (at the new battery bank location in the under bed storage in the front of the trailer) to that existing ground connection on the trailer frame. I'm just confused about what wire gauge to use. It seems like 4/0 or 3/0 are the best options. It's about a 6 foot run through my front wall, out of the bottom of my pass through storage, and then to the frame connection.

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[brainbone]

I have a SmartShunt, MK3 to USB-C adapter and a Smart Dongle. I'm hoping my Cables To Go brand UTP Cat5E cables will work in lieu of the expensive Victron cable? If not I need to buy a Victron cable.

Standard patch cables like that should work fine.

My 2021 Outdoors RV 280RKS trailer has 30 amp service. The 30 amp shore power inlet is a Furrion IM-F30ITX-V1 and the power converter is a Progressive Dynamics PD4060K. I will continue to use the PD4060K as my 120 volt AC and 12 volt DC panels and take the converter off line. The 30 amp line in is 10 AWG Romex. I'm assuming the PD4060K will accept up to 8 AWG Romex since the manual provides torque specs for 8 AWG as well as 10-14 AWG; it doesn't provide specs for 6 AWG .The shore power inlet will accept 6 AWG, I think; I called Furrion and they said they "think" it will. Some people have posted regarding having issues connecting smaller Romex to the MultiPlus 3000. Some folded it over and some spliced to thicker wire.

I wouldn't advise folding it over. 8 AWG should be fine, provided you're going into a 30A breaker. If you were going into a 50A breaker, then you'd want 6 AWG.

Most examples I've seen on any of the Multiplus' seem to show a critical error: Way too short of AC wires, no slack inside the Multiplus chassis, leading to bad connections. When coming into the box, you want about 6" to 8" of wire. Loop it up, then back down, making an upside down U. Then strip back the recommended amount for the connector, insert and torque down. (On the Multiplus II, you tap in a small screwdriver into the release, insert the wire, then pull the screwdriver from the release. Older Multiplus, insert wire, torque down.)

Here's a video for the proper way on a Multiplus II, the non II will be similar, just different terminal type.

Power Assist sounds nice but I only want 30 amps. Can I configure the MultiPlus to put out no more than 30 amps?

You can use Power Assist with a 30a panel. No need to turn it off, but you can. You can also set the multiplus to limit how much it pulls from shore, using power assist to fill in the rest when needed. The 30a breaker in your panel will limit the load and should be fine as long as the wire from your Multiplus to the panel isn't subject to getting shorted out.

A 30 amp breaker in between my shore power inlet and the MultiPlus would be good but I am having trouble finding a small set up.
It seems that since my generators won't be exceeding 30 amps and shore power hook ups usually have a 30 amp breaker that I could forego a 30 amp breaker in between the shore power inlet and MultiPlus. Would that be OK? Has anyone else gone that route?

The breaker from your shore power and the one in your generator is probably good enough, but you can find 30A din breakers and smallish 2 space din enclosures for cheap if you're losing sleep over it. In my opinion, just another terminal connection that can overheat and fail.

I'm wiring the DC to the MultiPlus with 2 x 1/0 as recommended in the service manual with a 400 Amp Class T fuse in between the positive connection bus bar and the MultiPlus. I will run a ground from the negative load bus bar to the chassis. From what I've read it sounds like the chassis grounds for the controllers and the MultiPlus should run to the negative load busbar which is grounded to the chassis. Correct? I'm not certain what size wire is needed for the controller and MultiPlus chassis grounds.

I ran the same cable size I used for battery to multiplus as I did for battery negative to chassis*. Just to be clear, the Multiplus' negative terminal connects directly to the bus bar that's connected to the battery, not indirectly through the chassis, just like the positive connection.

Edit: * Minimum size of wire should be based on what you're fused for and length of wire.

 

[HRTKD]

I will continue to use the PD4060K as my 120 volt AC and 12 volt DC panels and take the converter off line.

Huh? Are you keeping the converter or not? I recommend ripping that POS out of there and tossing it into the garbage can (or sell it on Craig's List*). The Multiplus is a far better charger than the converter. You certainly don't want the converter running when the Multiplus is inverting.

I used 6 awg wire between my RV's main distribution panel and the Multiplus. Consider the type of wire used. Flexible wire is a heck of a lot easier to deal with in an RV. I thought mine was flexible, but it wasn't flexible enough. @brainbone's suggestion on looping the wire is good. Always run a few extra inches (feet) of cable. When I ran my cable I thought I left enough extra, but I didn't. That made for some very frustrating connections.

I put in a dedicated ground (not negative!) busbar. All my equipment grounds went to that, then I ran a suitable cable from it to the RV's frame.

Some people add a circuit breaker from the shore power port and some people don't. I didn't. The shore power pedestal already has one. My on-board generator already has one.

* - I recently sold the PD9360 that came out of my new camper on Craig's List (Denver) and got $90 for.

 

[Rocketman]

Rather than Romex look for good multistrand wire - Marine wire is good to RV’s. The vibrations of the rig causes issues with solid wire.

 

[brainbone]

Huh? Are you keeping the converter or not?

I was confused by this as well. I think the PD4060K is a combination load center and charge controller. I read it as they're bypassing the charge controller to disable it, but continuing to use the load center portion?

 

[HRTKD]

I was confused by this as well. I think the PD4060K is a combination load center and charge controller. I read it as they're bypassing the charge controller to disable it, but continuing to use the load center portion?

Ah, thanks for the clarification. In my prior RV's main distribution panel, the converter was in that assembly, but in a separate compartment below the breakers/fuses. The main distribution panel itself is OK to continue using. Either disconnect or pull the converter out of there. It looks like the wires from the converter can be easily disconnected.

 

[RV Steve]

brainbone, HRTKD, and Rocketman. Thanks for your input. Brainbone is correct. I am using my PD4060K as a breaker panel for 120 volt and fuse panel for 12 volt. I can easily unhook the wire for the power converter at the 15 amp breaker where it gets power and put a wire nut on it; then it's still in place if I ever need to service the MultiPlus. HRTKD I like the idea of a dedicated ground busbar. I actually have an extra set of busbars so I'll used one of them for that purpose. Rocktman the 6 and 8 AWG Romex are stranded but only 7 strands. Marine wire surely is more finely stranded. The RV manufacturer used solid 10 AWG Romex and didn't bother running it through conduit. Going to 8 AWG Romex will be an improvement albeit not as good as marine wire. Since I plan on limiting my system to 30 amps max on the 120 volt side the 8 AWG Romex will be oversized.

 

[HRTKD]

I've never seen conduit in an RV but I don't have exposure to the higher end RV's that might use conduit.

 

[6716]

@RV Steve I am doing a similar build, adding the Multiplus to a system with a PD4000 series box in it. My plan is to turn off the converter breaker in the 120v breaker section. Fortunately for me there is room in the space where the 30 amp service comes into the travel trailer for the Multiplus, so my plan is to run a fresh wire from the shore power receptacle to the Multiplus power in, and then run power out to a junction box where I connect to the existing wire going up to the PD4000.

@HRTKD I'm not saying the PD unit is amazing but it is already fully wired for all branch circuits, with a clean cut-out to the trim panel. And disconnecting the converter is as easy as flipping a switch. I can't see pulling the unit and doing all that extra work just because the converter which can be switched off is nowhere near as good as a Multiplus.

Maybe there's something else I don't understand though. That happens a lot.