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Whats the best way to see activity on L2 using ESS

I'm running a DC coupled ESS system (mode 1). My panel is split phase not 3 phase. I have essential loads on AC out 1 Connected to L1 in the breaker panel (120v). I am not currently using AC out 2 for non essential loads they are still in the breaker panel. Aside from moving those loads to AC out 2, What alternative do I have to to monitor L2 in VRM and have ESS take it into consideration? I do have an EM24 That is not hooked up to the system. But if I use it it supersedes the current monitoring of the multiplus plus, that is my understanding. Any suggestions?

duswami asked
duswami answered ·

4 Answers

USB to RS485 interface extension cable

Since the usb to rs485 intereface comes in either 1.8m or 5m what is the recommended way of extending this to another 20m? Would a cat 6 cable be suitable for instance?

Cliff Raccani asked
mk1 commented ·

2 Answers

Clarity on AC pass-through on AC1 OUT

Am I understanding correctly the grid AC passes through the Multi AC1 OUT when the inverter is in charging mode ONLY?

duswami asked
duswami commented ·

1 Answer

Question to Wiring Guide / wiring 3-phase system (3x Multi) via busbar to 2 batteries


I have designed a three phase system (3x multi plus, 1 with GX) that are connected to a bus bar and then to a battery rack (10 kWh total) as shown below. The cable wiring from each MP2 to bus bar is 2m, from the bus bar to the battery < 1,5m. According to the manual, I chose for the 48/5000/70s 70mm² wiring.

Now I encountered the following issue during installation: the batteries use proprietary cable connectors that were supplied with the batteries but they can only fit 35mm² wire. I also tried 50mm² wire but it doesn't fit. As shown in the picture, I am already using 2x35mm² for each pole (1 to each battery).

According to wiring guide the cables running from bus bar to battery should be thicker (or equal) gauge than the ones running from bus bar to the MP2s. Given the short distances, does it really matter here? Obviously I could reduce all cable sizes, but that doesn't seem to make sense to me. What is the issue with the battery cables being thinner at 35mm² (given that is the recommended cable section from the manufacturer)? What can I do?

Many thanks!!!


krouink asked
bhi answered ·

4 Answers

Wiring in series or parallel


Looking for some advice, am very new to solar!

Ive got 2 panels (340 Watt, VOC 41.55, Vmp 34.73)

The controller is the mppt 100/50

The battery is a renogy 100ah smart battery

Would I be best to wire these 2 panels in parallel or series ?

Sorry for the basic question! Any advice welcome regarding series and parallel pros and cons; wiring sizes etc appreciated. I'm a complete novice !

rayface asked
rayface answered ·

5 Answers

Cable or busbar for correct midpoint voltage?

In this section of the Wiring Unlimited book, the midpoint connections are illustrated as cables. Should the midpoints be connected to a busbar like the positive and negative cables in order to get the same midpoint voltage across each series?


damien-walker asked
johnsmith edited ·

3 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
cliff-white commented ·

4 Answers

Wiring for ESS

I've read through all the ESS documentation and wiring diagrams and read everything in the forum and watched several training videos about ESS and wiring for ESS and still have some questions, hopefully you all can help me get things sorted out!

When running ESS with no grid feed option and prioritizing PV to run essential loads (AC OUT 1) is a current transformer needed and what is the best method for isolating the essential loads?

Currently, all the loads are in one service panel before the inverter. I have divided the panel so my critical loads are on one side and non-critical loads are on the other side. I have a breaker interlock on the breaker receiving the AC OUT from the inverter and manually throw it when I need to power the side of the panel with critical loads, which is 120V as I am using a 120V Multi. Essentially, its more-or-less a combination of a UPS system and backup system intended for rare grid failure, but I want to use ESS to export as much PV as possible to reduce the Grid AC loads during the day (and charge the batteries.) Generally the system will use Grid AC at night and only use battery consumption when no Grid AC is available limited to a 50% SOC. My current configuration/setup is obviously not an optimal situation as I am not setup to back-feed the grid and have no intention to do so, but currently this 'manual' procedure is what I am doing until I better understand ESS and wiring for it.

When designing for ESS, is it appropriate to move all the critical loads out of the main service panel into its own subpanel and leave the non-critical loads in the main panel and/or should I be utilizing a current transformer? Also, is there a reason to use AC OUT 2 at this point, if the non-critical loads remain in the main service panel, as they don't 'need' to be utilized when Grid AC is not present. However, I would like the option to still use non-critical loads. Therefore, are ALL the loads supposed to be after the inverter on AC 1 and AC 2?

Is it best to have two dedicated breaker panels, one for critical loads (AC1) and one for non critical loads (AC2) and just use the main service panel as a distribution point for the Grid AC and the placement of the current transformer. Trying to understand the best configuration taking into account the ESS and Multi's capabilities. Below are several threads I've posted relating to this subject. Thanks in advance for an insights or suggestions and thank you to those who have already commented in previous posts, I look forward to your suggestions.

Schematic below


How do I setup ESS setup for PV priority

Automatic transfer switch

How does Multiplus II w/Cerbo ESS prevent AC backfeeding?

duswami asked
lifeingalicia answered ·

5 Answers

Automatic transfer switch

I want to add an AC sensing automatic transfer switch to manage the Main AC IN/Inverter AC OUT of the Multiplus II in order to take full advantage of ESS.

I noticed the VE Transfer Switch is meant for 220/230VAC. I'm using 120V AC in and Out. Can the victron transfer switch be used for 120 50A.

If not, what do people recommend. Preferably, I want to be able to carry 50A on a single 120 leg (wire cross-section appropriate.)

duswami asked
duswami commented ·

0 Answers

two rcd's or a single rcd isolation transformer and multiplus


What are the guidelines with RCD's with a mobile (boat) setup that has shore power going thru an isolation transformer and then to a multiplus? Should there be two RCD's installed in this situation (one after the isolation transformer and a second after the multiplus or is a single RCD after the multiplus correct)?

It is also my understanding that a type "A" RCD is not good enough and a "B" type trip rating is needed.

The setup is 230V@50Hz shore and output.

Thanks for your help

lyric asked
Mike Dorsett answered ·

1 Answer

SmartShunt Positive Connection

Must the SmartShunt positive wire be connected directly to the battery post or can it be connected to a positive buss bar 12 inches from the battery?


msmolow asked
roachmon answered ·

3 Answers

Multiplus II 120v warning lights on startup

Just connected a multiple plus 2 120 V To the service panel via the AC input with 6/2 wire through a 50A breaker and got several lights. No batteries are connected to the system, but system is connected to lynx distributor.

When AC 120v is turned on I get a Bat Low solid light (I figure this because of no battery presence.) But I get what looks like a half moon dimmer red light on both Temp and Overload LEDs. No audible sounds, no burning smells. I turned off after 5 secs. What are causing these? Check polarity on AC, everything is good.

duswami asked
duswami answered ·

1 Answer

Panel cable length should be matching?

In a setup of 6 panels (445w) , 2 series of 3 in parallel, do the solar cables need to match in length up to the junction, as they do when connecting batteries inverter, charger etc?

For sure the final NEG/POS do not need to match. But I have read some that say that the parallel connections should match between them and also the serial connection should match between them..

Minas Papageorgiou asked
vickly answered ·

4 Answers

Smart shunt placement with lynx distributor

Confused about smart shunt placement with lynx distributor. My understanding is after the Neg battery terminal and before the first load or charge point. In the case of using the Lynx Distributor, my batteries, charge controller and inverter are all on the bus bars. Does this mean I go from neg terminal to shunt to Lynx distributor in-line with by battery connection to the distributor?

duswami asked
kevgermany answered ·

1 Answer

Wire size requirements for Quattro 48/5000

I'm installing a pair of Quattro 48/5000 inverters. They'll be approximately 10' (3m) from my batteries. The owners manual discusses wire sizes but I'm not sure if that's total circuit length (positive + negative) or each individual wire (positive OR negative).


If I'm at a total of 20' (positive + negative), then I need 2 x 70mm.

But if I'm at individual wires at 10', then I just need 1 x 70mm.

Any guidance?

learntorv asked
piraya answered ·

1 Answer

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