Re: How to make the most of Victron Multi-Plus Inverter/Charger on SM#387

Dan Carlson

Thanks for all the feedback on my proposal, and any more to come.  

I remembered one important question I left off of the original email: GROUNDING on the Victron Multi-Plus? For those that have installed the Victron Multi-Plus, how did you handle the grounding? And did you use have to change the configuration of the grounding relay on the Victron? 

Regarding the 50a vs 16a; my logic was that I only run the generator when I need the to run the watermaker. The need for water is greater that my day to day energy deficit.  Therefore I set up the Victron for the lesser of the available shore power current or generator excess over the watermaker. In my case that currently is 10amps.  My sense check after living on the boat for 20 months out of the last three years is that will supply the needs of our lifestyle.  In fact it will greatly expand our capability to is AC because 1) when the generator is running and I switch on AC devices the Victron will automatically adjust the current going to the batteries to stay within limits. And the power assist will allow me to draw from the batteries at peak times to supplement the 10a limit to the panel up to 2x (20a).  Likewise when on shore power I still have the same capability.  If I went with the 50a, then I would need to remember to switch my input current limit from 16a to 25a and back when going between shore power in the marina versus generator at anchorage. 

I realize in these discussions it should not be about whose lifestyle on the boat is right, but for a given owners lifestyle are they installing and setting up the right systems. And taking in not only the right considerations for their current way of living as well as potential changes in the future... For us, this will also be the potential demands of induction cooking. 

Thanks and regards, Daniel Carlson on sv BeBe at Shelter Bay Marina

On Mon, Dec 9, 2019, 11:45 AM ngtnewington Newington via Groups.Io < wrote:
On Amelia I have a Trace 70A charger 2.5KW inverter that I bought to replace the old Dolphin 100A Charger that was defective when I bought the boat. I wanted an 100A charger but the Trace was on special offer and available at the time, from Budget Marine in Grenada.  With all my solar/wind that is absolutely fine on the charging side.

When it came to wiring in the inverter side I decided not to until I had spent some time on the boat. So it was initially only used as a charger. I found that I only wanted the inverter to use a toaster and a coffee machine, and vacuum cleaner and other minor appliances in the galley area.  I considered various wiring options, but they were all discarded . So what I have done is run a cable from the inverter 240v output to a  new single socket in the galley. Labelled 2.5KW inverter. 

I know this is a bit primitive, but I have found that it works fine. The advantage being that I have not messed with any of the Amel original AC installation. There is no risk of any generator/inverter/shore power contamination or confusion. I am still reliant on the original Amel installed automatic Shore Power/Generator switch. 

I am happy with this simplicity. In general when I run the washing machine; the desalinator is also running, as well as the hot water and chargers. I reckon that we would be pulling 30A, so 7.5 KW. A job for the 11KW Onan.

When installing new equipment on Amelia I am always mindful of the Amel way but more importantly the philosophy: 

Kind regards


S/Y Amelia AML 54-019

On 9 Dec 2019, at 15:47, Roque <ediroque@...> wrote:


I am sure what the Victron technician meant with shore power / generator was either one and not both, of course. The word 'simultaneously" was referring to AC and water heater use, in his example.


His point was only to help one chose between the 16A and the 50A transfer switch. 

Attika A54 #117
Paraty Brazil    

Em seg., 9 de dez. de 2019 às 12:22, Mark & Debbie Mueller <brass.ring@...> escreveu:
You stated that “For example, should a water heater and Air conditioning unit wish to be used simultaneously and in conjunction with shore power / on board generator the 50A unit would be chosen (50A - 11.5kW peak loads)”.  If I understand that you are connecting the shore power and generator simultaneously to the same circuit it is been my experience that catastrophic failures occur in the generator and likely some components between the generator and shore power unless the generator has some fairly sophisticated phase matching capabilities, I do not believe the equipment on our boats have that capability.  The generator must have the capability to match the peaks and valleys of the sine wave supplied by the shore power input.


Failures of this nature typically occur when a transfer switch fails connecting both shore power and generator.  Search message #46769 for a recent example of this on an Amel.

Mark Mueller
Brass Ring  A54

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