Victron Multiplus install questions

[Txfivver]

Hi Jim, somehow I missed this thread! Congrats on the new fridge, I knew you'd love it, I sure do enjoy mine. Good luck with the inverter install and enjoy the frozen ice cream lol.

[Drolaw]

Hi Jim, somehow I missed this thread! Congrats on the new fridge, I knew you'd love it, I sure do enjoy mine. Good luck with the inverter install and enjoy the frozen ice cream lol.

Thanks - So far so good on the fridge. The temp difference is night and day and DW is a happy camper. The down side, if there is one, is DW will now have more grocery bags for me to load up before our trips as she will fill up the larger space...and I will have ice cream in the freezer...

The inverter install is delayed pending additional cable and parts. I hope to have it done next weekend.

[rwcran]

The blue arrow in your diagram points to a DC shunt for a battery monitor. Your diagram does not show a battery monitor but perhaps you have one similar to the Victron BMV-712?

Did AMsolar configure the Multiplus 3000 for you before they shipped the unit and was it programmed specifically for your AGM batteries? If it is configured incorrectly for your batteries you can possibly damage the batteries. Do you have solar panels and a solar charge controller connected to the batteries? You should remove your existing charger/converter and wire your RV's DC distribution panel directly to your DC AGM battery power bus. I installed a disconnect in the DC line from my battery bus to the DC distribution panel like the switch shown in your diagram located in the Multiplus DC line. This allows me to disconnect my DC distribution panel if I need to. Not mandatory, but a useful addition. I have a system similar to yours using a Multiplus 12/3000/120 with four 100 AH Battle Born lithium batteries. My RV solar system has six 200 watt solar panels, a Victron MPPT 150/100 solar charge controller and a BMV-712 battery monitor. I don't have the central monitor shown in your system. I monitor everything using Bluetooth with my smart phone and configure/program the multi using the Victron VE.Bus Smart Dongle and my Laptop with the VictronConnect App. The same applies to programming the MPPT controller. One feature of the Multiplus I like very much is the power assist. I have a Honda 3000 watt/2400VA generator so the power assist is useful when boon docking allowing me when powering from my generator to have my RV's air conditioner on and also use the microwave for short time periods. Without the Multi power assist I could not do this.

Roger

[Drolaw]

The blue arrow in your diagram points to a DC shunt for a battery monitor. Your diagram does not show a battery monitor but perhaps you have one similar to the Victron BMV-712?

Did AMsolar configure the Multiplus 3000 for you before they shipped the unit and was it programmed specifically for your AGM batteries? If it is configured incorrectly for your batteries you can possibly damage the batteries. Do you have solar panels and a solar charge controller connected to the batteries? You should remove your existing charger/converter and wire your RV's DC distribution panel directly to your DC AGM battery power bus. I installed a disconnect in the DC line from my battery bus to the DC distribution panel like the switch shown in your diagram located in the Multiplus DC line. This allows me to disconnect my DC distribution panel if I need to. Not mandatory, but a useful addition. I have a system similar to yours using a Multiplus 12/3000/120 with four 100 AH Battle Born lithium batteries. My RV solar system has six 200 watt solar panels, a Victron MPPT 150/100 solar charge controller and a BMV-712 battery monitor. I don't have the central monitor shown in your system. I monitor everything using Bluetooth with my smart phone and configure/program the multi using the Victron VE.Bus Smart Dongle and my Laptop with the VictronConnect App. The same applies to programming the MPPT controller. One feature of the Multiplus I like very much is the power assist. I have a Honda 3000 watt/2400VA generator so the power assist is useful when boon docking allowing me when powering from my generator to have my RV's air conditioner on and also use the microwave for short time periods. Without the Multi power assist I could not do this.

Roger

Hey Roger - AMsolar did program the Multiplus 3000 before they shipped it so I should be good to go. I don't plan to install solar this time but will in the future. The DC configuration is something I'm a little nervous about. Since I don't have a bus bar I'm guessing I just connect it directly to the batteries but I haven't looked inside the DC panel yet to see if I have enough wire to run from the panel to the front bay. Or if the wire is already directly connected to the batteries.

If I go with a bus bar what amp rating should I get? Do I need a positive and a negative side? That's been my only question I cannot find an answer for.

[IrishSchooner]

Hey Roger - AMsolar did program the Multiplus 3000 before they shipped it so I should be good to go. I don't plan to install solar this time but will in the future. The DC configuration is something I'm a little nervous about. Since I don't have a bus bar I'm guessing I just connect it directly to the batteries but I haven't looked inside the DC panel yet to see if I have enough wire to run from the panel to the front bay. Or if the wire is already directly connected to the batteries.

If I go with a bus bar what amp rating should I get? Do I need a positive and a negative side? That's been my only question I cannot find an answer for.

Installing solar panels and upgrading inverters are an awesome way to improve boon docking and camping in general. Installing a multiplus 3000 is exactly the way to go. Before installing solar panels and a Multiplus 3000 I read every article I could and watched dozens of videos online. I came away with the fact that most everyone had a different approach. And like you, there were some answers that were just a bit elusive... no real written answer. Having been involved in telecommunications and utility projects for years I took a fairly simple approach which has worked out well for us. First and foremost, I recognized that our Imagine (2670MK) was already working correctly... meaning that the existing system and wire was exactly what was needed to operate the RV as designed. Secondly, I realized what I wanted to do was to enhance the existing system. Therefore my approach was to add or enhance the existing system... not take away or remove. So rather than pull out wiring, the inverter\converter, add bus bars and pull wiring my approach was simple.

I purchased a MuliPlus 3000, some lithium batteries, two battery switches, a 500 Amp Fuse block, solar panels, two 60 amp breakers, and an MPPT charger from Battleborn. I mounted the MultiPlus, placed the batteries, mounted the solar panels and MPPT. Ran a ground wire from the MultiPlus to the frame of the 2670. Then disconnected and removed the original battery. Turned off the breaker switch to the original converter\inverter and then disconnected the hot wire to the breaker and taped it because it was no longer needed. Ran a positive and negative 1 gauge cable from a Battery switch mounted next to the Multiplus to the existing 12 volt system (its pretty easy and only about 8 feet in length) because the 2670 12 volt system will now be using the lithium batteries which are being charged by the solar system or the MultiPlus. To connect the MultiPlus to the 2670 110 volt electrical system I bought a 30 foot 50 Amp power cord and cut it in half. I used one half (leaving the plug ends on) to feed the inverter and the other half to connect to an outside power source... shore power or generator.

When boondocking I connect the output AC plug from the MuliPlus to the original RV electric connection by simply plugging in the power cord and turn the inverter on. Everything works like being plugged into shore power. The solar system charges the batteries and the inverter can run everything from televisions to air conditioners to microwaves. When we are able to connect to shore power I connect the power input cable to the plug on the inverter and the output AC plug to the original connection. This allows me to turn off the MPPT and let the MultiPlus charge the batteries while supplying power to the 2670. The nice thing about this is that I can connect to 120 volt power and still run all of the electric in the 2670 because the MultiPlus makes up the difference if it is needed. I can still connect the 2670 directly to shore power without connecting through the MultiPlus if I want to at anytime. I did install soft starts on both of our AC units. This may not work for everyone... it works for us and was a fairly simple and easy approach for us.

[rwcran]

It makes a cleaner install to have both a positive and negative DC power bus. Make sure the DC battery monitor shunt is placed in the negative bus correctly so all DC load currents pass through the shunt (no loads should be connected between the battery negative and the shunt). I made my bus using solid copper bar and stainless bolts, nuts and washers. The bus must be able to handle high amperage in the range of 200 - 300 amps continuous. For example if you are not running your generator or no shore power connected, the multi can be providing an AC load up to 2400 watts (with power factor of 0.8) and 3000 watts to a pure resistive load. This translates into a DC load from your batteries of (2400w/12.6vdc)/0.93 = 205 amps. The multi inverter is 93% efficient. The Multiplus under some operating conditions can draw up to 540 DC Amps peak for 1 to 5 seconds. I have attached a picture of my installation showing the positive and negative bus I made. I used 1/4" x 1.25" copper bus bar ordered from:
https://www.onlinemetals.com/en/buy/...-rectangle-bar

Roger

[gbkims]

Since I don't have a bus bar I'm guessing I just connect it directly to the batteries but I haven't looked inside the DC panel yet to see if I have enough wire to run from the panel to the front bay. Or if the wire is already directly connected to the batteries.

If I go with a bus bar what amp rating should I get? Do I need a positive and a negative side? That's been my only question I cannot find an answer for.

For connecting to your existing DC wiring, it appears you can connect the 4/0 wires from the Multiplus to the battery(s).
The OEM DC wiring connects to the bottom of the small copper bus in your phot, then through an auto reset CB up to the Passthru Disconnect & then on to the RV's DC Fuse Panel & Converter.

For future Solar a Busbar for Positive & Negative can be handy.
They can be as simple as a single Power Post, on up to Busbars with several studs.
Like these, available with different stud sizes (5/16", 3/8") to match up with the size of lugs install.
Fastronix 3/8" Stainless Steel Single Stud Power and Ground Junction Block Red and Black
250A DC, Fastronix 3/8" 4 Stud Power and Ground Distribution Block with Cover
500A DC, BEP Marinco Pro Installer 500 Amp, 4-Stud Heavy Duty Bus Bar

Busbar Amps capacity needs to go up as more batteries are added to supply the Multiplus.

Attached a diagram as how I thought your OEM DC wiring runs thru the front compartment existing copper busbar.

Forgot to ask if you had a crimper for the 4/0 lugs or if they were crimped from AM Solar.

[Drolaw]

Well today is shot - it's raining and electricity and water don't mix.

@gene - amsolar did not crimp the lugs to the cable - I'm using a crimper I brought on amazon.com. It's a 16 ton hydraulic crimper. They would have done it for me, for an additional fee, but I had already bought the crimper so I didn't have them add that to my order.

Thanks to Gene, Roger, and others for your help. I feel confident about the installation but have 2 questions I hope someone can answer.

1. Can I install the Multiplus in the 5th wheel front storage bay with my 2 (acid) flooded batteries? I read the following in the manual: "Note that the inverter cannot share an area where combustible fuel vapors exist because switching components could cause ignition. Corrosive battery fumes should also not be present." I'm not worry about the combustible fumes but I am worried about the battery fumes. Any feedback?

2. Do I need to need to maintain 18" from the battery pos (+) terminal to the fuse? I read this on one of amsolar's diagrams.."All fuses and fuse holders should be located within 18 inches of the battery " I'm guessing this is to the fuse itself and not the inverter? Meaning, 18" from battery terminal to the middle of the fuse?

Gene - hope the pics help re: your fuse question.

[gbkims]

Well today is shot - it's raining and electricity and water don't mix.

@gene - amsolar did not crimp the lugs to the cable - I'm using a crimper I brought on amazon.com. It's a 16 ton hydraulic crimper. They would have done it for me, for an additional fee, but I had already bought the crimper so I didn't have them add that to my order.

Thanks to Gene, Roger, and others for your help. I feel confident about the installation but have 2 questions I hope someone can answer.

1. Can I install the Multiplus in the 5th wheel front storage bay with my 2 (acid) flooded batteries? I read the following in the manual: "Note that the inverter cannot share an area where combustible fuel vapors exist because switching components could cause ignition. Corrosive battery fumes should also not be present." I'm not worry about the combustible fumes but I am worried about the battery fumes. Any feedback?

2. Do I need to need to maintain 18" from the battery pos (+) terminal to the fuse? I read this on one of amsolar's diagrams.."All fuses and fuse holders should be located within 18 inches of the battery " I'm guessing this is to the fuse itself and not the inverter? Meaning, 18" from battery terminal to the middle of the fuse?

Gene - hope the pics help re: your fuse question.

Jim,

For the flooded batteries, do they have the vent hose?
It's is best practice to have them enclosed in a battery box and vented to the outside.
That keeps the flammable hydrogen vapors and corrosive sulfuric acid fumes away from the electrical equipment.

For the Class T fuse they're recommending 18" or less from the battery positive.


Fuse photos let me know the type of fuse, looks like a 5x20mm slow blow.

[Drolaw]

Jim,

For the flooded batteries, do they have the vent hose?
It's is best practice to have them enclosed in a battery box and vented to the outside.
That keeps the flammable hydrogen vapors and corrosive sulfuric acid fumes away from the electrical equipment.

For the Class T fuse they're recommending 18" or less from the battery positive.


Fuse photos let me know the type of fuse, looks like a 5x20mm slow blow.

They do have a vent hose. One is attached to the hose that goes to the front vent of the RV. The other has an opening at the bottom but no vent hose. They are both enclosed in separate battery containers. I plan to switch to lithium at some point (probably spring).