This article details the installation of the US Version of the Multiplus 12/3000. This is a 12 Volt DC 120 Volt AC inverter/charger. The official title is MultiPlus 12/3000/120-50 120V VE.Bus and the title indicates that the inverter output is 3000 VA, the charger is rated for 120 Amps and it has a 50 Amp transfer switch. This blog post details unpacking, mounting and wiring your new MultiPlus, subsequent articles will detail the programming options.
Quick Install Sheet
If you have built an Ikea bookcase you will instantly recognize the style of the Quick Install Sheet. It is showing you what is in the box, what isnt in the box, how to mount the unit and how to wire it up. Its just not that easy to follow, so I am going to attempt to interpret in in conjunction with the other more detailed manuals, all of which lack drawings, and I will maybe throw in a photo or two for good measure.
This is an ABYC requirement. Lead acid batteries give off corrosive gases that can destroy equipment directly above them, even sealed batteries can vent corrosive gases on occasion. The drawing is showing you that the multiplus needs some space around it for ventilation. The Service Manual gives you more details about the mounting including the following: "The product must be installed in a dry and well-ventilated area, as close as possible to the batteries. There should be a clear space of at
least 10cm around the appliance for cooling." and also "The device can be fitted either horizontally or vertically. For optimal cooling, vertical fitting is preferred." There is more mounting information in the Service manual
Mounting is super easy
You screw the mounting bracket to the wall. Hang the Multiplus on the bracket. Pop two screws in the bottom to stop it jumping off. If you are installing it horizontally the same applies.
Connecting the small cables
This next diagram is a bit confusing because the current model of the multiplus doesnt look like the drawing. At this point it would be helpful to have an actual photograph to see what it really looks like. As we go along I will explain what all the connections are.
In the service manual Appendix A gives a drawing to help identify the components and connections.
The connections for the small wires are all in the set of green terminals in the very bottom of the photo. They are all labelled as E in the drawing above. The image below shows what they look like without the wires in the way:
The first pair labelled T-Sense are for the temperature sensor. The sensor mounts on the battery negative terminal. The wires are labelled + for red and - for black.
The Aux1 and Aux2 are input terminals and are programmable. We will discuss these when we get to the programming section in a future blog post, typical uses include remote control from the BMS of a Lithium Battery System where they could be programmed as "allow to charge" and "allow to discharge"
The trickle charger terminal can be used for charging an auxiliary battery such as a starting battery. This is just the positive connection. The battery negatives must be common to each other. Max output is 4 Amps
K1 and K2 terminals are relay contacts which are programmable and can be used for example to operate a starter relay of a generator
The V Sense wire can be connected to the battery to give a more accurate reading of the battery voltage that avoids the voltage drop in the battery main cables. Installing a voltage sense wire is not required but it does give improved performance because the sensor reads the actual battery voltage and can compensate when charging for up to a one volt drop in the cables. There is a + and - connection that goes to battery positive and negative. (A fuse is required)
Main Battery Cables
The next panel shows the main battery cable connections. In the diagram above they show a single positive and a single negative cable, but if you look at the picture below you can see there are two studs you can connect to for each with the intention that if necessary you can double up the cables. The diagram above does not show a battery switch but in the ABYC standards this is a requirement. You need to be able to turn this off if there is a problem or if you want to work on the system. The service manual goes into the cable size in some detail.
The service manual suggests using doubled up 1/0 cables for the main supply and suggests using a 400 Amp fuse for the 12/3000 multiplus. A Class T fuse would be appropriate for this application. The ABYC has quite a bit to say about using doubled up connectors like this, I have summarized it in the footnotes. According to my reading of the ABYC standard if you were using standard 105 Deg C rated battery cable you would need to use 4/0 awg cable if you had a 400 amp fuse in the line. The main principal to bear in mind here is that the cables carry a lot of load and the load carrying capacity must match the circuit protection. If doubled up cables are used the ABYC says each individual cable must be capable of carrying the entire load by itself and they must share a single fuse. The cables need to be as short as possible to reduce voltage drop, the longer they are the greater the cross sectional area needs to be, and the less voltage drop there is the better the performance.
Aux Battery Charger
This next panel shows the charging circuit for an auxiliary battery such as a starting battery. It has a maximum 4 amp output. The drawing shows that the Aux battery and the Main battery must share a common negative. Then the only wire you need for this is the positive wire. The drawing doesnt show a fuse for this wire but one is required at the battery end. The wire connects to the terminal labelled "trickle charge" in the middle of the set of green terminal strips.
Connecting a remote panel
A remote panel is not included with the multiplus but is sold separately. There are two versions, the Digital Multi Control and the Digital Multi Control GX. These are functionally identical but have a slightly different appearance, the GX version is designed to match the appearance of the Color Control GX. The port is called a VE Bus port and the cable needed for this is the RJ45 UTP cable also sold separately. It plugs in to the position labelled "B" in the big drawing above and the photo at the end of this article. There are two adjacent sockets and you can plug it into either, they are identical. There are other things you can plug in there too including a parallel cable to connect multiple units or the new VE Bus Bluetooth Dongle. Here is a photo showing two devices plugged in.
AC Case ground
There is a terminal for connecting an AC Case Ground. I wasnt able to find any written reference to this in either of the other manuals. The ABYC does have some things to say about case grounds for inverter chargers though.
AC Output Connections
The MultiPlus 12/3000 had dual AC Outputs. AC Output 1 is the main output. It supplies power when shore or generator power is available or when the inverter is on and is the output on which the Power Assist is available. AC Output 2 is only available when shore or generator power is online and doesnt work when the unit is inverting. You could wire on this output something like a water heater that you didnt want the inverter to be able to power. Each output has terminals for Line, Neutral and Ground. The Ground output is shared between the two outputs. Here is a photo:
I'm told AC Output 2 is limited to 32 Amps max (the manual says 25 Amps but that apparently is a typo) and the service manual indicates that it must be protected by circuit protection of a maximum of 32 Amps. The Service manual details the recommended wire sizes based on a 50 Amp shore or generator input, see below. The output wires are sized to add the inverter's Power Assist amps to the shore or generator power available. For configurations with less than 50 Amp shore-power/generator power or installations where Power Assist is disabled it should be possible to reduce the necessary wire size by reference to the ABYC tables.
AC Input Connections
The AC input terminals are on the extreme left and comprise a Line, Neutral and Ground terminal. Recommendations for wire size are shown in the table above and are based on a 50 Amp shore or generator supply
Finishing the Installation
I didnt show the last panel becasue it just says to put the cover back on. Before you do you may want to check your work. Have you got the polarity right for the DC terminals? Reverse polarity on these is a fatal error that will destroy the unit. Are the bolts tight? Have you mixed up your incoming and outgoing AC connections? Are those screws tight? Have you connected all the optional extra devices? There are also a few things you might like to look at before you close the lid so I have annotated the photo below with some notes. For most installations you will want to at least do some basic programming of this device. The most basic programming is done using the dipswitches and that requires the cover to be open. Anything more elaborate should be done using one of the computer interfaces available. That will all be dealt with in my next blog post. You might also like to make a note of the model and serial number, and the processor number as these are all things you might need later and its a lot easier to write them down in the manual than it is to go and open up the unit again. In the photo below I used the same letter key as in the drawing earlier in the article. Below the photo is a list of what all these items are.
A AC Input connections
B VE Bus ports for remote panel, parallel configurations etc. (Both ports are identical - you can use either or both.)
C AC Output 1 - this is the primary output
D AC Output 2 - only works on shorepower or generator and is limited to 25 Amps
E Optional ports for temp sensor, voltage sensor, programmable options
F DC negative connection (dual terminals available if double cables are used)
G DC positiove connection (dual terminals available)
H Connector for remote switch (on, off, charger only) If you have a Cerbo GX in the system you can only use this remote switch option if you have a MultiPlus-II, it cannot be used with the model shown in this article. (see manual of Cerbo GX for more details)
I Programmable relay alarm contact.
K On-Off Push buttons used in conjunction with dipswitches for basic programming
M Dipswitches used for basic programming
N Slide switches. Slide switch 1 is used for the ground relay function if the unit is connected to an autotransformer. Switch 2 is not currently used for anything.
X Main Processor, make a note of the number in case a firmware update is ever needed (hint: take a photo) The first four digits of the processor number must match the first four digits of the firmware file name.
Y Serial number and model number, make a note or take a photo.
All the above is taken from Appendix A of the service manual which has additional information on the functions of each item.
Other versions of this MultiPlus
The 24 volt version of this should be almost identical (24/3000) The "Compact" 12/2000 Multi Plus is a bit different, it only has a single AC output and it has a greatly reduced number of terminals for optional connections.
I will add in photos of other models as they become available. This first set of photos is of a 48 Volt 5000 VA Quattro. You can click on the thumbnail to enlarge the photos. The first one is the AC wiring area and the second is the DC wiring area and all the small connection points.
The following manuals are available for the MultiPlus, Im not sure which ones are in the box:
ABYC 220.127.116.11.1 A battery switch shall be installed in the positive conductor(s) from each battery or battery bank with a CCA rating greater than 800 amperes or 100 Ah if CCA is unavailable.
18.104.22.168 Non-motor Loads - The current rating of the overcurrent protection device shall not exceed the maximum current-carrying capacity of the conductor being protected (see TABLES 6A-B). EXCEPTION: If there is not a standard current rating of the overcurrent protection device equal to 100% of the allowable current for the conductor in TABLES 6A-B, the next larger standard current rating may be used, provided it does not exceed 150% of the current allowed by TABLES 6A-B.
22.214.171.124.8 Paralleling of Conductors – conductors of #10 AWG and larger shall be permitted to be connected in parallel where the ampacity of each individual conductor is sufficient to carry the entire load current shared by the parallel conductors. NOTE: Paralleled conductors may be used to achieve the appropriate voltage drop or wire bend radius with smaller individual cables.
126.96.36.199.8.1 Overcurrent protection of paralleled conductors shall be sized to protect a single conductor.
188.8.131.52.8.2 Paralleled conductors shall be of the same length and gauge.
184.108.40.206.8.3 Paralleled conductors shall be run together in the same cable, bundle, or raceway.
Here is a link to the Ampacity Tables referred to above, in almost all cases we are using battery cable with 105 Deg C insulation. According to the ABYC if you put a 400 amp fuse in the line then you have to use 4/0 cable. Two times 2/0, which has the same cross sectional area, doesnt comply because the individual cable is not capable of carrying 400 Amps. I called them up at the ABYC to get some clarification on circuit protection for doubled up cables. You can use either one fuse or two if you have double cables, but in either case the fuse needs to be sized for what a single cable can carry.
From A-31 BATTERY CHARGERS AND INVERTERS
MOUNTING 220.127.116.11 To avoid corrosive fumes, battery chargers, inverters and inverter/chargers shall not be installed directly over batteries.
31.6.5 DC GROUNDING CONNECTIONS 18.104.22.168 The DC grounding conductor shall, 22.214.171.124.1 be connected from the metallic case or chassis, to the engine negative terminal or its bus, and 126.96.36.199.2 shall be of an ampacity equal to that of the DC positive conductor. EXCEPTION: The DC grounding conductor may be one size smaller than the minimum size conductor required for the DC current carrying conductors
Peter Kennedy has been in business since 1991 designing, installing and servicing marine electrical systems. The purpose of this blog is to offer support to both professional installers and do-it-yourself boat owners who wish to undertake this work themselves.
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Thank you Peter for this excellent post; I have a question in regards to the remote panels and their functions that are available. I understand that there are two, the Digital Multi Control /GX and the Color Control GX. I was hoping that the Color Control GX could handle all or at least the main functions such as input 'current limit' and 'on/off/charger only'. From the manual of the Color Control GX i understand that for 'some' system configurations with the Multiplus these functions cannot be performed by the Color Control GX. One of the mentioned system configuration is a setup that uses the VE.BUS BMS which is a must for Li battery banks. Here Victron proposes the use of the Digital Multi Control AND a rocker switch for the on/off function. From my perspective hard to believe or do I misunderstand something here. I would love to have everything consolidated in the Color Control GX remote.
You can always turn the MultiPlus on and off with the Color Control GX. The one thing you cannot do on the Color Control is control the charge current if a VE Bus BMS is installed. For that you need one of the two Digital Multi Controls.
Great great article. Really simplified the process. My question pertains to the switching. Ac in from shore power, out to main Ac breaker. My reading of the manual says the battery charger will automatically turn on when it's receiving shore power. What if I connect my generator but do not want the battery charger to engage, can this be done?
The MultiPlus only has a single AC Input so there is not way for it to differentiate between generator and shore power. You would have to manually adjust the knob on the remote to turn the charging current to zero once you left the dock.
This an excellent "how to" for the MultiPlus and associated monitoring accessories. My specific question/concern is the chassis ground. I have a 1999 Beneteau 411. Are you aware of any concerns about grounding the chassis to the negative DC ground given that this model of boat does not have any bonding on its through hulls. I have heard arguments for and against grounding the chassis to the DC negative grounds. Thanks in advance for any thoughts you may have on this concern.
Connecting the inverter chassis to ground is an ABYC requirement. Here is the relevant paragraph: 31.6.5 DC GROUNDING CONNECTIONS 188.8.131.52 The DC grounding conductor be connected from the metallic case or chassis, to the engine negative terminal or its bus, and 184.108.40.206.2 shall be of an ampacity equal to that of the DC positive conductor. EXCEPTION: The DC grounding conductor may be one size smaller than the minimum size conductor required for the DC current carrying conductors.......
Wonderfull information. Thank you. Is there a way to program the 24v, 3000W, 70A Multiplus to run an auxiliary fan anytime the internal Multiplus fan runs? I'm installing the Multiplus I just received from PKYS into an unused battery compartment on my camper. I will need to provide an auxiliary fan to vent that compartment to provide proper cooling. Thank you again.
Yes you can do that. One way is desribed by a user who commented on my Blog Post: Programming your Victron MultiPlus inverter charger with the VE Configure program - Part 3 - "The Assistants" Scroll all the way to the end of that article to see his description of what he did.
Great article,Very informative! Can you program the Multiplus with a Venus GX or do you have to use the MK3 to USB adapter?
No you cant use the Venus to program the multiplus. As of April 2019 the only option is the Mk3USB interface. I have a number of other Blog posts that cover the programming.
Peter We are connecting a gas generator into system also Only to come on when batteries run low We have a sma invertor from panels Iam presuming the 230v from invertor and generator go in the incoming supply of multi plus ,same connection ,fused before getting to multiplus
Just beware that the inverter is not ignition protected and should not be in the same compartment as a gas generator. If your boat wasn't designed for a gasoline engine there's probably no vapor proof machine space and even mounting the inverter in a adjacent compartment could be dangerous.
If you have two AC sources for the Multiplus you must fit a selector switch to connect the active source since the Mult can only accept one input at a time. A Quattro can accept two AC inputs simultaneously and will automatically connect to the active source.
Hello Peter, Many thanks for an excellent article. I am reworking the installation of a Multiplus on a canal boat I recently bought. I am concerned that all the circuit protection is downstream of the Multiplus. Can you see any problem if I go from the shore power socket direct to a correctly current rated earth leakage circuit breaker then on to the Multiplus. Thanks again. Kind regards Peter Wilson France.
Peter, excellent article, thank you. RE: ABYC A-31.6.5: Are they really saying the case ground should be the same size as the DC positive conductor? That could easily be 4/0, or even 3/0 if you go one size smaller. I don't think I've ever seen an inverter case ground using 4/0 cable, have you? Would the provided mounting hardware even support a 4/0 sized lug?
The reason for this is that in the event that the DC Negative conductor came loose the DC Grounding conductor might end up carrying the charge current It says: DC Grounding Connections..."Shall be of an ampacity equal to that of the DC positive conductor" EXCEPTION it can be one size less provided that the overcurrent protection in the DC positive is no more than 135% of the ampacity of the DC grounding conductor.
Joseph R. Duncan
I m in the process of a solar panel and battery bank and charger inverter install and have run into a problem that I can t seem to come up with the best solution or work around for.... basically the Victron inverter/charger has an AC IN that has three connections and three connections for AC OUT but my Power Panel has four AC leads coming in; I believe this is because Fifth Wheel has a 50 amp panel ( I believe there are two hot legs a neutral and a ground ) ..... How do I make this work with my new Victron inverter charger ?? please help :-) I discovered this when I was about to disconnect the AC into panel and run it to the AC In of the Victron and then take the AC Out back to the service panel.... ps... it looks to me that the 2 hot leads one to each side of the fifty amp breaker is set up to service two different sides or halves of the service panel .. Thanks in advance for any and all help.. Joe
If you have four wires and a 120/240 volt system you have a few options. If you have a 120 volt inverter charger then by picking one hot and one neutral as the input you will then be able to get the inverter /charger to work on one leg only. If you get a second identical inverter charger you can do the same thing for leg two and in the process also be able to get 240 volts. Alternatively If you exchange your 120 volt unit and get a 230 volt inverter charger and an autotransformer you can have a 240 volt in and 120/240 volt output. This is discussed in my Blog Post "Generating a 120/240 Volt split phase power supply from an inverter"
Peter; thanks for this fantastic blog. I've found answers in here that I haven't found in a week of searching the net. I'm still confused about wire size and over-current protection for the DC side of the 12/3000. I won't have any cables over 6' long. I expect defaulting to 4/0 is the safest approach but it's a bit pricey and harder to work with. I will need it from the + battery to the switch (rated at 300A), and from the switch to the inverter. On the negative side from the battery to the shunt, shunt to the inverter and shunt to chassis. (This is an RV by the way). What about the short jumpers between batteries - do they need to be 4/0? Since my switch is rated at 300A should I use a 300A fuse to protect the lowest rated device - or a bigger switch? Thanks for your help!
I see that doubled up cables are required for the battery connection. Why do you only have a single set running in the diagram? Is it as simple as just running two wires from the positive terminal and two from the negative and connecting them to their respective battery terminals?
Doubling up the cables is an option but is not a requirement. Victron have made it easy for you if you want to go that route by providing a place to attach them. The advantage of using doubled cables is that you can achieve a lower voltage drop and cables that are less unwieldy. If you do opt for doubling up the cables be sure to read up on the small print of how to arrange your circuit protection to keep it up to code. It gets a bit technical.
I have 2-120ac 30amp circuits in my coach that I have wired to my exsisting magnum inverter which has 2-ac outs I want them both powered from my new multiples 3000 can I combine them and run them both off the one ac out. If so what method of combining them would be appropriate I can’t afford a Qauttro
Peter, This blog has been the most helpful information I have been able to find, including the Victron manuals. I recently bought a Victron 3000 Multiplus 12v model inverter/charger for my motorhome while in Arizona and had it scheduled to be installed while we were there. Unfortunately, circumstances forced us to leave and return home before the installation date, so now I am trying to figure it all out by myself. I live in a very small town with no RV services. My question is this. My RV currently has a 1000w inverter that only runs the two televisions, even though the wiring diagram from Winnebago shows it powering multiple AC outlets as well. This is not the case. My dilemma has been how to connect the Multiplus into the system to power all these outlets without powering the air conditioner and refrigerator. From the previous post about the two AC outputs, it appears I can put the different circuits on the two different outputs, with my AC outlets on the full-time outlet and the aircon, refrig., etc on the shore/generator outlet. Correct? Does this mean I need to split the circuits in the current control center/breaker box and add a second breaker box and move these circuits to it? I had talked with two different installers. One gave me a bid which included a second breaker box and fuses, while the other was planning to tie into the wire from the auto transfer switch, directing it to the inverter and back to the power control center. This second option looks like it would have put all my electrical loads on the inverter, including the ones I don't want on it. I am understanding this all correctly? Your input would be much appreciated.
Thanks, Peter. In reading the manual for the Victron 3000, I saw that the max amperage through the AC Output 2 is limited to 25 amps. That is not enough to run the AirCon, which requires about 60 amps to start up. Should the AirCon circuit be connected directly to the incoming AC source (shore/gen) instead of running through the inverter?
According to my sources Output 2 is limited to 32 Amps so if you need more than that you need to use Output 1
Peter, Excellent blog, thank you. I have two house battery banks on my boat, 470 AH each. Can one Multi-Plus 3000 handle two separate battery banks? Thanks
Archie Glenn West
Looking at the 230v Quattro I only see on ac in one hot, neutral, ground. This is USA so I have incoming shore power 2 hots, neutral and ground. Do I combine L1 and L2 together and come into inverter?
The 230 volt Quattro can be used in a US 240 volt system provided that you set it up correctly. First you can change the voltage from 230 to 240 in the software, you can also change the frequency from 50 to 60 hz. Then you can connect two hot legs to the input instead of a hot and a neutral, We still have to make sure that we have a correct ground at all time, I can discuss that one on one in a support ticket, you can contact me through the support portal support.pkys.com
This is very helpful, thank you! I'm confused. I'm planning on getting a MultiPlus 24|3000 120V, and because I'd read it had a built-in automatic transfer switch, I thought I would NOT need an external ATS. However, traditional ATS's switch between shore and generator power, but with only 1 AC input on the MultiPlus, it can't do that. So will I still need an external automatic transfer switch to switch between shore and generator power? The internal "ATS" only switches between shore/generator power and inverter power? If this is correct, the MultiPlus's internal ATS is NOT a traditional ATS, it's really just a UPS functionality? Or am I completely confused? Thanks in advance!
The MultiPlus has an automatic transfer switch for a single input, (shore or generator). It will automatically switch to inverter if the external input is not available.
If you upgrade to a Quattro it has two inputs (shore and generator) and will automatically select the active input. It will automatically switch to inverter if neither external input is available.
Peter, Great article. We are doing install right now. Having problems fining torque specs for install of various wires. Do u know torque spec for 4/0 ground wire? Appreciate any help you can offer.