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Common wire to connect PV arrays on SmartSolar MPPT RS - 450/100

Good Day,

Is it possible to use a common ground, to connect the 2 arrays PV input for the charge regulator SmartSolar MPPT RS - 450/100?

Because the regulator is far from the panels, and I have only 3 wires from the connection box.


partenope asked
wkirby answered ·

1 Answer

Phoenix Smart inverter grounded to my RV chassis, should the negative of the (dedicated) battery feeding the inverter also be connected to the chassis?

As per the title above. I searched through the excellent Victron Wiring Unlimited guide and here in this forum, but couldn't find an answer.

Just to make it clearer, I say it's a ''dedicated" battery because it's completely separated from the vehicle's pre-existing battery system, and it's connected only to the Victron inverter (with separate 70mm2 cables) and to my PV charge controller.

Thanks in advance for your help.

durval asked
wkirby commented ·

1 Answer

Autotransformer balancing

Does the autotransformer balance the output and the input 120 lines, or just the output, or just the input? I'm confused!

brianv asked
Mike Dorsett answered ·

1 Answer

Autotransformer wiring for balancing loads, split phase 120/240

My AC source is split phase120/240. It supplies two hot wires and a ground, no neutral. I am using a Victron transformer because I am splitting the two phases into two separate battery chargers for my RV, but I need the loads on the two hot wires to remain balanced. My question is, would it be correct to connect the two hots AND the ground into the autotransformer, and then use the two 120 lines, the new neutral (created by AT), and ground coming from the autotransformer to connect to my loads (battery chargers)? Any potential issues with that set up?

brianv asked
wkirby answered ·

1 Answer

Autotransformer output capacity

I am confused as to what the actual output of the autotransformer 32 and 100 amp is. I see that the neutral caps out at 32 amps on both. So does that mean that the total output of either autotransformers is 3840VA in split phase 120/240? It doesnt make sense because if you are connecting let's say two 120v 5000VA Quattros to the AT to create balanced split phase current, you basically lose a bunch of output capacity. Or is the 100 amp version able to output 100 amps total between the two 120 lines?

brianv asked
wkirby answered ·

2 Answers

Smart Lithiumbatterie 12V wiring question
Hello we change on the boat from 2X130 Victron AGM to 3 Smart Lithiumbatterie 12,8V/200Ah. Now I understand that I need a Victron VE.Bus BMS to Balance the Cells.

But I don´t understand why I need a BMS 12/200, it looks like that is just a Isolating diode. To protect the alternator I use the Victron DC/DC 12/12-30 to load the Lithiumbatterie.

I´m wrong or right, do I overlook something?

Thanks for the Help!

cheshunt asked
cheshunt commented ·

1 Answer

Common Neutral in Domestic Situation

Hi All,

I need some solid engineering input on this question of making input and output inverter/charger neutrals common. I have seen the Common Neutral thread which is for a different application. This is a static application situation - a problem I have been battling with for over 6 years on all my projects.

It is essential to state the two key problem causes and why they are not solvable:

1. Our municipal grid has been degrading severely over the last 30 years with poor maintenance causing neutral disconnections and ground-neutral bonding issues on the utility/transformer side. This is getting worse due to utility having little finance and incompetent maintenance staff.

2. House wiring standards are not adhered to in many site cases meaning joins on neutral in ceilings/conduits for multiple electrical circuits. Or missing neutrals. To fix this (compliance issue) takes up a huge amount of time which customers are mostly not willing to pay for so I have found myself working hours, days, weeks and months for free to sort out these issues. Why is this a problem? Apart from the obvious electrical problems and neutral overloading, in my country customers cant afford to go off-grid so we split the house wiring into "inverter powered" and "grid powered" circuit (btw: we have daily power outages everywhere). Which means inevitably we will have a neutral fault or a common neutral somewhere in the wiring due to these non-compliant situations. So it may be worth common-ing inverter and grid neutral in the main distribution to "draw" the connection off house wiring - just a thought as the worst thing is to power a circuit without a neutral - our utility conditions has done us the honor of doing the "hands-on" test for us - to the detriment of equipment or lots of SPDs.

So my question: Is there any electrical compromise I can look into? - to stop me from sponsoring customer's compliance because of the nasty 80% of electricians who cheat and make lots of money.

Maybe some specific protective device or solution including common neutral, a specific SPD? some RCD that works -

* a 30mA RCD is not an option - electricians bypass them because of continuous tripping.

* off grid not an option as customers can't afford it.

* redoing site wiring not an option because customers can't/ don't want to afford it

* me quitting the business is a less than ideal situation as with 90% unemployment rate in my country other lines of work are just as difficult.

So to all the engineers out there who like solving problems please HELP! :D

P.S. I'm an Electrical/Electronics Engineer with more knowledge in Electronics than Electrical Power - I have fair experience with the effect of surges and earthing issues in electronics ;)


kenyon asked
kenyon commented ·

3 Answers

Mppt 100/30 installation wiring

I have an older Morningstar pro star 30 and want to replace with a new mppt 100/30. The old prostar has solar, battery and load wiring.
The 100/30 seems to only have solar and battery wiring.

What do I do with the load wires ?

pymsa asked
randy-putnam answered ·

2 Answers

Off grid wiring digram

Hi there,
This is how I am planning in wiring my off grid tiny house on wheels (essentially a caravan) and just wanted to see if anyone can see any issues with it? Is the earth circuit correct? Photo attached.

I haven't drawn any of the AC side of of the installation for the purposes of this diagram but I'd like to add that in addition to the connections in this diagram, I will also have:

-All the earth's from my AC loads will connect back to my negative buss bar
-A large cable (same size as battery cable) joining my negative buss bar to the trailer chassis.

Another note - The reason I have run the MPPT positive cable through the other pole on my DC isolator is because when I switch that off I want everything to stop, including the charging of my batteries. I realise I can just turn the PV isolator switches off and achieve the same result, but I want it all to turn off with the flick of one switch.

Sorry for the long winded question and thank you in advance!


Brandon asked

0 Answers

Wiring a Victron Battery monitor 702 - another question

Hi All

Thanks to those of you who responded to me regarding my previous post. Unfortunately I had posted an incorrect diagram - that caused some confusion - I have reposted the correct diagram here. Apologies I am not even an amature electrician!


1) I assume I can still attach all black wires from house to shunt battery only

2) Then all black from start battery to Loads and Chargers

3) then included red wires to shunt/red terminals of batteries as indicated

4) confused through about black wire that goes between black house and black start (in diagram) - feels like that would circumvent shunt if connected to both Battery Only and Loads and Chargers as per above?

5) will switching system still work?

6) I have a battery voltage meter for both batteries - might it be an option to just put Victron on House? If I did - do I leave the black cable between battery on shunt and black on start? Again - feels wrong.

7) will charging system still work - from engine alternator and 20A charger?

Thanks all - really appreciate the support!!!

kaz asked
kaz commented ·

1 Answer

Catamaran Electrical System Refit


We are assisting our client which has a Leopard 48 in a refit job. Our client has purchased a bunch of Victron products and we have some questions regarding the recommended way to connect them.

The items recently purchased...

1x 12v/3000 Quattro

4x MPPT 100/30

4x Panasonic 325N Solar Modules

6x Smart Sense Battery Monitors

1x Color Control GX

1x Digital Multicontrol 200GX

1x BVW 702 for monitoring 2 engine batteries

The yacht has 2x 100ah AGM batteries for engines and 4x 210ah gel batteries for house.

The engine batteries are connected to Blue Sea ACR's which are probably connected to the same bus bar as the house batteries so they would charge while under propulsion.

We have some questions:

1. Each solar panel is connected to it's own MPPT(For safety reasons each panel is 70 Volts). Will there be enough ports to connect the MPPT's to the Color Control GX?

2. How will the MPPT's know when to stop charging the batteries? I know there is the VE Network via Bluetooth but the 4 house batteries are connected to the same bus bar. I suppose the Smart Sense Battery monitors should be connected individually to each battery?

3. If possible, will the MPPT's be able to send all their data to the Color Control GX and show an aggregated sum?

4. If shore power is hooked up, how will the Quattro know when to stop the charging for the batteries? I believe the Quattro has two outputs for charging of batteries. One output to engine batteries and one output to house batteries?

Is there a Victron Pre-Post Sales Engineer that could help out with these sort of things?

Thank you

David asked
chrispi answered ·

3 Answers

Design pour un CC avec EBL existant

Salut les gens

Je suis de retour et en français cette fois, plus simple pour moi aussi !

J'ai apporté des modifications quant à la première conception postée sur forum anglais, y compris avec le matériel existant.

L'équipement existant, encadré en vert en bas à droite, est physiquement situé à l'intérieur du véhicule. Les lignes vertes partent de l'EBL119. L'EBL119 est une unité électrique d'origine et intégrée dans le véhicule. Elle est utilisée pour la distribution du courant 12V / 220V et pour la gestion d'une seule batterie de service cabine AGM ainsi que d'une batterie de démarrage. L'EBL119 n'accepte que du 12V / 220V. Je n'ai pas encore déterminé la section des câbles, mais cela dépendra aussi des longueurs, à voir sur place.

Dans mon précédent post sur forum anglais, on m'avait conseillé de passer du 12V au 24V pour tout le système. Mais au vu de l'EBL119 présent et que je veux garder pour la gestion de tous les éléments internes, frigo, éclairage, alimentation externe... je vais rester au banc 12V.

Mon objectif :

- Retirer les éléments encadrés par une ligne verte en pointillés ainsi que les lignes en pointillés verts: batterie de service et ligne directe 220V vers la distribution des prises.

- Laisser l'EBL119 en place mais en installant un interrupteur à 3 positions pour la distribution du 220V dans les 5 prises existantes du véhicule: 0- pas d'entrée de courant, 1- alimentation 220V par le convertisseur, 2- alimentation 220V de la connexion externe au véhicule.

- Recharge des batteries Lithium avec un Buck-Boost grâce à l'alternateur / Euro-6.

Reste à résoudre:

- Recharge du banc de batteries Lithium 12V par l'alimentation externe 220V de l'EBL119 ou directement par une alimentation séparée à un chargeur? Je ne connais pas encore le meilleur. Peut être avec un convertisseur / chargeur au lieu du seul convertisseur.

Ou pluôt, rester en 12V avec les batteries, comme ça, pas de souci avec l'EBL119 ( comme sur mon design joint ). Ou quand même mettre tout en 24V ( selon les commentaires apportés depuis le forum anglais ).....Argggg...je ne sais plus par où commencer ou plutôt finir...

Cela vous parle-t-il et suis-je sur la bonne voie?

Merci beaucoup pour vos fabuleux commentaires sur ce projet.


myhomebuzz asked
myhomebuzz commented ·

3 Answers

Your evaluation before installation

Hi Folks

Before installing my system in my motorhome, I wanted to submit to your experiences on this installation.

The green part is the support panel. The cables pass through the rounds to pass to the rear. This forms like a door with a hinge to facilitate assembly and to carry out subsequent additions of elements. The dimensions of all elements are exact dimensions in mm. The thin cables are in 2.5mm2 or VE.Direct or USB, the medium ones in 16mm2, the batteries in 35mm2. The battery fuses are 175 ANL. The red lines are + or Line or Phase, the black lines are - or Neutral.

No cables cross and the support panel is 80 cm x 60 cm, made of fireproof wood. Did I miss something in this assembly diagram?

I thank you in advance.


myhomebuzz asked
myhomebuzz edited ·

5 Answers

Split combiner box feeding 2 SmartSolar mppt controllers off a common negative bus bar?

Hi, I am wondering if it is ok to use a Midnite Solar 6 breaker combiner box with the positive bus bar split in two and use it to feed two Victron SmartSolar mppt charge controllers using the common negative busbar? Each controller would receive their own positive and negative cables, only the negative busbar would be shared.

The arrays would be different sizes feeding into a Victron 150/100 and a Victron 150/70 feeding into a single battery. Midnite Solar states most charge controllers can work in this configuration with a few named exceptions (Victron not being one of them). There is a diagram similar to this setup on page 5 of this document:


I just want to make sure before I make a potentially expensive mistake! Thanks in advance for any help.

iqyax asked
iqyax commented ·

1 Answer

Wiring sizes for Victron Energy Orion-Tr Smart 12/12-Volt 30 amp 360-Watt DC-DC Charger, Isolated

Good morning,

I had a quick question regarding wiring gauge for the charger.

I am installing the charger in my travel trailer and on the input side (pickup truck) I am connecting it to my starter battery on my pickup truck (I have a 220A Alternator). FYI - I am not an electrician or mechanic and wanted to check what I am doing is safe and will work with the Charger.

With that the total cable run is 10-12 meters which according to the Victron manual is 16mm2 (6 AWG), however, other references call for 4 AWG. This is based on cable run length (10M), 40A max load at 12V. Will the Charger accept a 4 gauge (AWG) cable?

Please let me know if you have any questions. I have attached a diagram for your reference.

Thank you very much for your help.

Have a great day.

Best regards
Eric Patten

Truck Side Dc to DC Charging Diagram.pdf

eapatten asked
eapatten commented ·

1 Answer

Installing IP22 battery charger

Hi there. Can I use a AWG 11 (4 mm2) wire to connect the IP22 12V/30A to three 74 Ah/680A wet batteries, at a maximum distance of 2,5m? Also, shall I install fuses between the charger and the batteries? If yes, how many Ampere? Thank you in advance for the hints. Max.

massimo asked

0 Answers

Peak power/fuse sizing Phoenix 12/1200

I am sizing a fuse/wiring for this inverter. Would I be right in saying the peak power is double (so 2400W) and so my fuse size should be 200A? We are using power heavy tools so expect that they may dip into the surge capacity when spooling up. Also, is there an internal fuse built in, and if so what size?

tristanhooft asked

0 Answers

Wiring 3 parallel batteries with IP22 w/3 outputs


I have a smaller motorboat with 3 parallel batteries. 1 starter and 2 consumer batteries.
I have bought an IP22 Blue Smart with 3 outputs, and I wonder how to connect them to the charger correctly.

I have made an figure of how I suppose is the correct way, but I am unsure if it really is that simple?
Should I add fuses on any of the wires?

Thanks a lot in advance for your support.

BR - Pjet Barn

pjetbarn asked
pjetbarn edited ·

4 Answers

MPPT update to charger panel wiring

I recently Upgraded to SmartSolar Charger MPPT 100/50 for my RV setup. I presently have 3- 160W (8.38A) Flex panels run in parallel to the charger (based on advice for my previous 30A PWM charge controller).

I am looking to add a 4th panel to the setup and more storage capacity. my question is wether I should add it in Parallel as well or should i rewire for series or series/parallel for this new controller? attached is previous wiring Diagram with old charge controller for reference.

Any advice would be greatly appreciated.


m-beach asked
Rob Fijn commented ·

3 Answers

100/30 wiring diagram

I brought the 100/30 mppt charge controller wanting a full wiring diagram picture how to wire it up as I'm not sure. solar panels to unit to battery and do I need to put a fuse or circuit breaker somewhere what size if I do any help would be great thanks I have 1 300w solar panel and two 12v batteries

donkeydave1980 asked
Cansin Sari edited ·

2 Answers

Camper van system wiring with BMS and solar

I`m converting an old fire fighter van to a offgrid camper.

I already own a BMS12/200, BMV, Shunt and MPPT from the previous owner of the vehicle.

I do not find a wiring diagram for the BMS with solar on the website.

Can an expert please check my diagram and give me feedback if that set up is correct and save.

Is the LiFePo battery fully protected against any harm by the BMS?

Is the Starterbattery protected from discharge and the alternator from overheating by the BMS?

Is it correct to connect the MPPT on the load side of the BMS?

Is the MPPT 75/15 suitable for 3x90Wp Victron Blue Solar panel in serial?

If MPPT connection on the load side of the BMS is correct, what fuse do I need on the load side of the BMS?

Many thanks for your help!!!

best regards



steve77 asked
dazey77 answered ·

2 Answers

VE Smart Shunt and VE Multiplus dongle...are they supposed to be powered up all the time?

VE Folks -- I have 100A Smart Shunt and a Smart Dongle for a Multiplus installed in my RV (recently). Following VE instructions, both bluetooth devices are connected to the (+) battery post...so they are always powered. My question: For an RV environment where the unit is stored for several weeks at a time (sometimes months) these devices are never disconnected from battery. Are they intended to remain powered up at all times? I realize they have minimal draw (less than 1ma) but it seems odd to leave them powered up. Any advice is appreciated...thanks!

goodoz asked
goodoz commented ·

1 Answer

BMV712 shows current but no history


I have installed a BMV712 and believe everything is wired correctly, we have a voltage reading and the current also registers values but when we tap the history tab there is next to nothing showing.

The shunt is wired with a single 95mm2 link cable to the negative of a 3x110ah battery bank. That is the only wire that side. The right of the shunt then links into the boat (its on a narrowboat) and has about 3 or 4 load wires coming off it. The battery bank has nothing but link cables going between the negative poles and the positive only has link cables except the most positive battery with the loads again.

Overnight our battery went too low, we inherited the system a few weeks ago when we purchased the boat so I'm not sure if we have a duff battery bank. I'm confused how current it flowing via the shunt yet there appears to be little to no history.

When installing the shunt we ensured all loads got switched off and clicked the calibrate button. Running some loads last night showed a negative current and running the generator this morning activating the built in charger showed a positive current.

The 12v wiring consists of a split charge relay from the starter, solar input and a Freedom 20 inverter and 12v circuits.

When we purchased the boat the previous owner had the first battery feeding the positive and negative loads and some other loads on the middle and end battery. We rewired the bank so all negatives were fed from most negative battery and positives from most positive. I'm not sure if they've damaged the batteries in the way they had it wired up.

stevebates asked
dazey77 answered ·

3 Answers

48V batteries and MPII, DCDC 48-12 - common negative? Yes/no, why?


Can anybody give me (or point me to) a proper explanation if the negative from the batteries (48V) and the negative from the DC-DC-converter out (12V) can/should be made common?

Im my case the 48V batteries will feed the MPII, the BMS however requires 12VDC, and therefor I will also connect the CerboGX to the 12V sytem, because this will be buffered - in case BMS shuts off 48V Batteries, the BMS and Cerbo will remain running for a certain time to see what is going on in the system.

If memory serves right, then the Cerbo can only be connected to all other units, if they use a common negative (-)/ground?

So: Common ground yes/no? Why?

Thank you.

basti asked
Paul B answered ·

1 Answer

Wire gauge for MPPT 150/70? 2x435watt (Voc: 85.6v Isc: 6.43amps each) Marine use on 12 lead acid.

Good evening. I have a 12 volt boat with 6 group 31 AGM batteries (4 house/1 engine/1 thruster-generator).

I purchased 2 used SunPower 435watt panels for use on my small boat. A really good deal on 2 year old panels.

The panels are Voc: 85.6v Isc: 6.43amps each (not sure what they mean, but believe max volts and max amps while short circuited.

I purchased a Victron SmartSolar 150/70 controller. I believe I could have gotten away with the 150/60 per the Victron sizing calculator, but little over kill doesn't hurt. The boat will be in the tropics and likely pretty hot inside and outside the boat.

I will run them in parallel to make them more resistant to shading.

In parallel, I assume I'll have about 15 amps max and 90 volts tops out of the panels.

On the boat roof, I plan to wire the panels + to + and - to - before running the two individual wires into the boat. The 150/70 will be mounted about 30 feet from the panels. I looked on a page that said don't exceed a 2% voltage drop. I need 4 gauge marine wire (tinned for salt water exposure) to do 30 feet. BUT, I'm a car guy....4 gauge is for starting a car! 30 feet of 4 gauge seems ridiculous. Is this correct? Its only 15 amps, not starting a car.

On the battery side, I should size for 70 amps (150/70 charge controller rating) and 10 feet max run to reach the batteries. I should then use the same 4 gauge wire. Even if amps are higher, distance run is lower.

Is my wire sizing correct? Thanks all.

serpa4 asked
serpa4 commented ·

2 Answers

Wiring an Orion-Tr Smart 12/12-30 Isolated DC/DC charger on a 2018 Winnebago View

Hello, I'm trying to install the Orion-Tr 12/12-30 Isolated DC/DC charger in my RV. The instructions seem very straight forward but when I add all of the other components it becomes confusing for me. I have included a sketch of the current wiring. It is my understanding that when the engine is running the battery banks are combined via a 1g wire for charging. If I wire in the Orion via the maximum 6g wire wouldn't the 2 banks still be combined via the stock 1g wire going between the 2 banks? I would appreciate any input.


RV wiring sketch pdf.pdf

mr-b asked
Trina edited ·

2 Answers

Fine Strand (1666pc) 4AWG to 150/70 MPPT TR?

The manual is somewhat unclear on this, so thought I'd ask. I've got 1666 strand with 0.127mm strand diameter tinned copper 4WG cable (weave config 7x7x34).

The Manual states a minium amount of strands, but doesn't specify what the maxium strands/the minium strand diameter should be?

Will I be okay to use this wire into the screw terminal?

Ferrules don't appear to be something I could source locally. The main alternative is to source some different cable to go from the terminal to the breaker.


abstracted asked
Daniël Boekel (Victron Energy Staff) commented ·

1 Answer

Pre-Charge inverter - Are there potential issues with other DC side equippment during pre-charge?

Hello folks.

Am Currently building a system, and am wondering about the pre-charge-issue.

I have a BMS (SimpBMS), which will (after checking battery parameters) trigger a pre-charge contactor before triggering the main contactor. So far so good. I however wonder, how to pre-charge the inverter, while I have other items connected to the DC side of the battery (see drawing below).

Manually disconnecting all breakers/fuses for the 48V DC equipment other than the inverter, before system-(re)start is nothing I'm looking forward to. A second contactor (as in the drawing) might be an option, but also means additional and ongoing power usage (for my island system), therefor not ideal.

Can anybody clarify the issue, after looking at my over-simplified drawing (am lacking a schematics program)?

Thank you.


basti asked
Daniël Boekel (Victron Energy Staff) answered ·

1 Answer

Wiring a Victron DC-DC charger - HELP!


I want to install an Orion DC-DC Smart 12/12/30 in my van. It would be connected to the starter battery under the driver's seat all the way to the back of the van on the opposite side (passenger side). My question is, if I run the wiring up to the ceiling, to the back, and back down, the distance would be 10m one way (2m up, 4m to the back, 2m across, 2m down), if I run it through the floor the distance would be around 6m one way (4m to the back, 2m across). Keeping in mind derating factors (running continuously for more than 20m, being in a conduit or insulation), I've calculated I need a 0awg wire (50mm), which seems way too big. I don't know if my calculations are wrong? Victron recommends a minimum cable gauge of 16mm for a 5m distance (i'm guessing this would be one way?).

I'd appreciate any help!! Thank you

palomafts asked

0 Answers

Orion smart engine Switch


I'm getting a bit confused by the wiring diagram in the Orion smart manual. In this figure (most are very hard to see in the manual it show the ignition switch wired to the engine ignition power and them going to the H pin. but it also shows a bridge to the L pin. If im not mistaking adding this bridge will keep the unit always on..

I would like to have the unit charge from my house bank to my starter and bow thruster bank. I would like this charging to happen only when the engine is on.


polarseal asked
bathnm commented ·

5 Answers


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