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Multiplus-II GX and 230v AC with no neutral (still distributed in some part of Italy)

It Italy there still areas where distributor provide 230v AC without neutral (based on distribution of 3-phase 230v with no neutral)

In this situation, to connect the AC to a Multiplus-II GX in with no neutral it is enough to disable ground relay? (and connecting the ground to device chassis)

There is a specific procedure to do so?

Kind Regards,


blackstar asked
blackstar commented ·

1 Answer

Grounding with the Lynx Distributor

Can the Lynx Distributor (LD) ground nut be used for multiple ground connections like a bus bar, and then earth ground that connection to my AC service panel. I have a Multiplus II, MPPT Charge controller both chasis grounded on the LD grounding lug. I want to add my battery ground to the LD ground nut and then earth ground the LD to the grounding bus bar in my AC service panel. I'm following local codes but want to be sure this is a permissible connection. Also, I'm using the SmartShunt, would I ground the neg bat terminal or one of the terminals on the shunt instead. Thank you, any insight or opinions (regardless of code) is appreciated.

duswami asked

0 Answers

Ground Relay Error 8 with Fronius IG Plus when switching back to grid

Hy All,

we deliverd a new Installation (Number 8) to an "existing" Farm House with a 3 - Phase ESS 15 kVA - Multiplus II System.

There is a Fronius IG-Plus 120-3 running for more than 12 years. So good for now.

Everything is working fine except we start the system in "Island" Mode with an Active IG-Plus. When AC Mains is connected, the System performs its Relais Test and after about 5 Minutes it is going to switch back to grid. Immediately, when switching back we get an Ground Relais Test Error 8.

When starting in Island Mode with a disconnected IG Plus everything is working fine.. after switching back to grid and connecting the IG Plus everything is working like a charm.

When coming from Grid with a GridLost, we also encounter the same problem when switching back to grid.
To make a conclusion.. When the Fronius IG-Plus is "Connected" (we switched off the system, because it starts working after 30 seconds.. so we could not test, if its a problem when standing by connected and producing), we get an Ground Relais Test Error when switching back to grid. (Always)

Whats wrong...

There is no mixed Ground and Netral (We have controlled that several times)

The Multis are showing those ERRORS:

Phase L1, device 1 (0) #44 0x820002
Phase L2, device 1 (0) #15 0x800024
Phase L3, device 1 (0) #19 0x800024

From the wiring...

AcMainSwitch - SwitchOverToGenerator - 100 mA 3 Phase FI - MulitplusII - FI-s to different Loads

the IG Plus is connected:
IG-Plus - LS 16A - FI- 003 A -To The MulitplusII Ac Out

As talking to Fronius Service Personal the have no Idea what s going on, because they say they do not connect Neutral to Ground ... so do we have issues with the 100 mA 3 Phase FI, or the FI 003A connected to the IG Plus?

The System is running the latest Firmware 487.

Unfortunately there is no Support from our Dealer, because they do not have the knowledge.

Have a nice day, always Sun and I hope to get some good feedback...

thank s in advance


Bernhard Matschinger asked
Bernhard Matschinger commented ·

0 Answers

SmartSolar MPPT 100V 15 amp grounding questions

1. On the underside of the controller I see a screw with a lock washer, is that the ground for this device?

2. What gauge wire should I use? The rest of the system will be 10AWG. So 10AWG?

3. This is going into a travel trailer. The chassis ground of my trailer is hooked directly to the negative terminal of my battery. Would I just attach the controller ground directly to my battery negative terminal too?


bill-shackelford asked
wkirby answered ·

1 Answer

Ground Relay Safety

We use a MultiPlus Compact 12/1600/70 in our development vehicles to supply our measurement equipment with 230V AC. Now we have the question how the saftey of the Neutral-to-PE(Ground) relay is ensured.
- Does the MultiPlus test the functionality of the relais contacts?
- If yes, is there a documentation about this available?
- What is the reaction if the test fails?

Thank you for a helpful answer.

Best regards Timo

tien asked
tien commented ·

2 Answers

Lynx Distributor OK to use last negative stud for chassis ground?

I'd like to run chassis ground to the last negative stud on the lynx distributor - by last negative stud I mean the last stud on the neg busbar, the one that would typically be used to connect a lynx distributors to another lynx distributor. Is there any issues with that? I'm running a multiplus equipment ground to the dedicated ground connection on the lynx distributor. Thanks!

jeremyh asked
jeremyh answered ·

2 Answers

Orion-Tr Smart DC/DC control and grounding clarification


I am building a 24V setup very similar to the victron van install ( on a old Mercedes Benz truck (no smart alternator).

Instead of the Buck Boost, I will use the new Orion-Tr Smart 24/24-17A (400W) Isolated DC-DC charger behind a Battery Protect.

My negative bus bar and the enclosure of the MultiPlus are grounded to the chassis using 4mm2 wire.

The manual of the Orion-Tr Smart ( states on page 4:

"Remote on-off
Use the remote function to enable and disable the converter remotely with the remote on/off connector or using the
VictronConnect app. Typical use cases include a user operated
hard wired switch and automatic control by for example a Battery
Management System. If the minus of the service battery is not at
the same potential as the minus of the alternator or starter battery
an isolated remote on/off cable between the BMS and the on/off
port is required, see chapter 4.4 for details.

This should not be the case in a vehicle, but the on page 10, Figure 4:


there is an isolated remote on/off cable shown.

So here are my questions:

  • Is it correct to ground the negative bus bar and the enclosure of the MultiPlus to the vehicle?
  • Is it necessary to also ground the enclosures of the MPPT, the Orion etc. in such a setup?
  • Basically, I want to use the automatic "engine running" detection mechanism of the Orion-Tr to enable it. In case the VE.Bus BMS triggers the charge disconnect, the BatteryProtect on the charge side disconnects the Orion-Tr to protect the batteries. The question now is, if I also need to deactivate the Orion-Tr to protect it from beeing damaged, like with a MPPT? How would I do this? I have a "Non inverting remote on-off cable, ASS030550200" in my hands. It does not look like the one used in the diagram, it only has three cables (red, black, yellow).


kiko asked
Rod answered ·

1 Answer

Victron grounding

I need to double check grounding rules with the Victron Multiplus please… in our situation it will be used to power a coffee machine in a tent at a trade show. It will not be connected to shore power, it will only be operated in inverter mode. There is no chassis or hull to connect the Multiplus case ground point to and no connected metal parts that customers can touch, Is an earth cable to the case ground point necessary in this temporary use case?

ginesvadillo asked
wkirby answered ·

1 Answer

Multiplus II 12/3000/120 2x120V install - leaking significant ground current when charging only

I'm wondering if I have a bad Multiplus unit. I have just installed a Multiplus on my boat during winter layup with lithium batteries. As I am checking the install to verify that everything works, I decided to try to plug into a gfci to see if it trips. My dock has a RCD (30mA) on the shore power pedestal and I would like to have this figured out before we launch so I am using a GFCI outlet as a test. Unfortunately, it trips the GFCI as soon as the charger function comes on and starts charging the batteries. I have a dedicated leakage current clamp, so I checked the leakage current on the main AC-in and all is fine when you flip the breaker to give the multiplus AC power. It registers ~1.2 mA with the multiplus on. However a few seconds into the startup sequence, the multiplus charger turns on and starts ramping the current to the batteries in bulk charging phase. During this time, I can watch live with my leakage current clamp as the charger starts up the current go from ~1.2mA to 30 to 40 -50 mA +, all based on what I limit the current to the charger in the VE Configure software (ie charging current 50, 60, 80 amps etc). If I limit the bulk charging to 5-10 amps I can keep the leakage low. This is with a double pole breaker in the off position on the AC-out portion so nothing is really connected as a load and both N and L1 are open on the AC-out. The only load is the batteries being charged on DC. In addition, if in the VE configure software I click the box to disable the charger, then it doesn't trip the GFCI, and it works as normal with low leakage current, but of course without the charger functionality. Also, if the batteries are near full and the charger switches to absorption, the leakage current falls considerably into the 10-25mA region based on the charger output. I have been staring at this for a couple weeks now and I've tried just about everything with disconnecting all DC loads except the batteries, isolating neutrals for the inverting loads, and measuring leakage at each point. Thoughts on what I haven't tried, and or how to test if the Multiplus unit itself is leaking current to ground during the charging phase? What am I missing?

bice0004 asked

0 Answers

Grounding a phoenix inverter on aluminium sailboat?

Hello all, Currently, I only have the ground bolt from the inverter connected to the hull of our aluminium sailboat. I would like to know if there are any experts on galvanic corrosion within the marine environment that could offer some input or a website with images on the best practices for earthing/grounding dc battery pack, inverter, ac power and our electric ev motor. There seems to be a lot of differing opinions on this topic. Thanks Dennis

zzzdgr asked
zzzdgr commented ·

6 Answers

Disabeling ground relay not possible


I'm setting up my Multiplus II, I like to disable the ground relay setting but the checkbox is not able to uncheck. My grind is a 3f grid without N, only L1,L2& L3. Belgium grid is selected.

firmware 2623496 is installed. The multiplus is not connected to the grid at the moment, only battery power, could that be the reason?

Is there a possibility to disable the ground relay?

Kind regards Tim



tim-caesens asked
wkirby answered ·

1 Answer

How to ground an isolation transformer?

First post.

I have some difficulties understanding the installation manual of my 3600 VA isolation transformer I recently bought.

A quote from the manual:

“Figure 5: Output neutral grounding

A Residual Current Device (RCD) or Ground Fault Circuit Interrupter (GFCI) must be installed in the output cable of the isolation transformer. For this RCD to operate correctly, the output neutral must be connected to ground (= all the metal parts in the boat). This is achieved by placing a jumper on male push- on connectors J21, J33 (see fig 5), and by grounding the enclosure of the isolation transformer.”

The last sentence, does that mean I should add a separate grounding cable from the green/yellow grounding cable connected to the enclosure to my ground plate - or - is the grounding made by connecting the J21 and J33 connections?

I’m sorry if this question has been asked before. Grateful for help.

christern asked
christern answered ·

3 Answers

Orion-Tr Smart Charger 12-12 30 Isolated Input Negative Connection

Hi all, newbie here, I am currently attempting to install a 12-12 30 Orion-Tr Smart Charger Isolated into my 2012 Mercedes Sprinter Van, using the charger to take current from my van starter battery and pushing it to my 2 100AH Lithium Ion house/leisure batteries.

I am wondering if I need to be making my Input negative connection directly to the starter battery negative terminal or if I can be grounding it to the chassis, and if I can ground it to the chassis if it matters where that chassis ground is (closer or further from the starter battery). I am looking to minimize voltage drop in the circuit for best performance delivering a charge to my house/leisure batteries.

I called Dragonfly Energy (Battleborn) energy and they recommended connecting directly to the negative starter battery post, and this seems in accordance with the orion install instructions provided with the unit. They also mentioned grounding to the chassis instead of the starter battery stud could result in issues.

However, after some research on this form and others, I am getting conflicting information on the topic. There are other posts on this and on Sprinter Forum and this site that recommend either installing to the factory ground stud underneath the driver seat box or a separate ground.


    1. Mentions Mercedes Upfitter guide recommends against connecting directly to negative post for interfering with other electronics. Action recommended: Ground to Chassis stud under seat post
    1. Battle Born Cited: "You are able to wire the isolated version with a chassis ground for the input negative"
      1. This one is interesting because this is different that what was recommended to me when I called Battleborn.
    1. Cites grounding will work on isolated version

Given the above context, I find it confusing with the seemingly conflicting install guidance. Could anyone shed some light over why or why not I would connect the input negative for the orion to a ground vs connecting to starter battery stud. Tradeoffs grounding near my leisure batteries (I created a ground in the rear for this system) vs running cable back to the factory ground stud closer to the starter battery? If grounding to the rear, how does that affect my calculations for AWG sizing (if i can cut wire run by grounding to the rear, can I run smaller AWG since the "run length" is shorter?) Thanks so much for the consideration!

lundy asked
lundy commented ·

3 Answers

Frage zum Erdungsrelais

Ich hätte da mal ne kurze Verständnisfrage.

Das Erdungsrelais schaltet im Inverterbetrieb den Neutralleiter und PE des Ausgangs kurz,

warum fliegt bei eingeschaltetem Erdungsrelais der FI im Eingang des Multi´s?

michael-neumann asked
michael-neumann answered ·

2 Answers

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