Re: Inverter replacement

Mohammad Shirloo

Hi Nick;

We will currently be using the inverter/charger as an inverter only and keep the balance of systems and chargers as they are. We will not be connecting an AC source to the invert/charger, yet. I looked for the Amel schematics of the inverter/shore power/generator selector switch and found it in the original Amel schematics supplied with the Boat.

It appears that there is a selector switch between the shore power and the generator for the AC panel, except the 220V and the microwave breakers. The power for these goes through another selector switch that selects the power source from the selector output of the generator/shore power switch and the inverter. If there is power coming in from either the generator or shore power, then the inverter is disconnected.


Mohammad Shirloo
+1-323-633-2222 Cell
+1-424-644-0908 Fax

From: <> on behalf of ngtnewington Newington via <ngtnewington@...>
Sent: Sunday, June 27, 2021 10:32:06 AM
To: <>
Subject: Re: [AmelYachtOwners] Inverter replacement
1.Normally inverter chargers all have sleep modes. There will be a sensitivity setting that looks for a load. Some electronics demand so little power that the big inverter can not see it. This searching will use a little power.

2. If there is an AC source applied to the inverter charger then it will automatically bypass inverter mode and become a charger and all AC demands that would otherwise be met by the inverter are now met by the AC supply.
So in practice if the generator is running or shore power, so long as the 100A charger switch is on then the outlets fed by the inverter will be fed directly by the AC source.
If however the 100A switch is off then the inverter will supply those outlets.
So with Lithium, if you are happy there is enough capacity you could just use the big inverter to supply the whole AC part of the boat simply using the inverters internal change over switch.
I know some people think that is not belt and braces enough…but …..not sure.

S/Y Amelia 

On 27 Jun 2021, at 10:19, Mohammad Shirloo <mshirloo@...> wrote:

Our original 2500W Mastervolt inverter died at the end of the season in 2019. We have purchased a new Mastervolt Mass Combi ultra 3500/24/100 inverter charger as a replacement. This will also act as a backup charger and be ready for future upgrades to Lithium and solar installation. For now, we will just be utilizing the inverter function to have A/C when off grid and generator not running. So, the wiring is fairly simple and the original battery and A/C wiring will be connected to the new unit.

The new unit does not have a remote switch, like the original that is installed on the generator panel in the galley. The new units have control displays that we will be adding in the future. It is possible to leave the inverter on in sleep mode that utilizes minimum power, or go into the engine room and turn unit off at the unit. 

My question is regarding the switching of the A/C going to the main panel when multiple sources of power are available. I’m assuming that the inverter A/C wiring is connected to the priority switch that selects which source of power is feeding the A/C panel Just want to be sure that if the inverter is on and either shore power or generator is supplying power, the inverter is not in the circuit and is OK to leave the unit on all the time, if we elect to do so?

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