Inverter/Charger wiring advise

John Clark

Hi All,

  I am installing a “whole house” inverter/charger, a MagnaSine 4124 (230v/50hz.)

I explained to the vendor, Inverter Service Center in Tennessee , how the Amel electrical system has a floating DC negative and separate ground/earth/bonding connection.  He recommended this unit specifically for the boat because it is a native 230v/50hz not a US 240v/60hz unit tweaked to produce 50hz.  The grounding/neutral setup is apparently incompatible in those North American units.  


The Magna has an automatic transfer switch that will select incoming AC power or inverter output, incoming power preferred.   Both the hot and neutral AC lines are switched.   When it selects the inverter for AC output, the AC neutral is connected to chassis ground/earth by a “system bonding jumper” which I unplugged per instructions to keep the bonding separate from the neutral. 


I double checked the unit after unpacking and there is no continuity between the chassis ground/earth and the DC negative, and also  after unplugging the “system bonding jumper” there is no continuity to the ground from the inverter AC neutrals.  I intend to connect the chassis ground/earth to the Amel bonding system and leave the DC negative floating.


I intend to mount the unit next to the Dolphin charger on the port side of the engine room.  This is where the old HVAC compressor sat and is close to the main battery disconnect bus work.  The DC cable run should be less than one meter.  


Attached is a picture of my proposed wiring.  Is this how the unit should interact with the Amel bonding system?


Green is the Amel bonding system as it is wired on my boat and how I intend to connect the new inverter/charger. 


Pink is the location of circuit breakers.


I currently have two battery chargers powered from the 230V distribution panel, a 30A Dolphin, and a 40 A Mastervolt.  These were installed by previous owner.  


The AC panel is powered through a 40amp breaker and an automatic transfer switch which chooses between the 7KW Onan Generator or shore power.  Generator is preferred. Generator has a 30A AC breaker.  All as was installed by previous owner.


Inside the AC panel the bonding/earth connections (green/yellow wires) have no conductivity to the AC hot(brown) or AC neutral(blue).


There is a 600 watt inverter installed under the nav station that powers a portable 230v/50hz power strip.  No part of this unit is connected to the Amel bonding system.  Again all previous owner installation.


We have had no issues to date with galvanic corrosion.  We replaced rudder anodes in Charleston in August and they still look new.


And all this work is so we can make popcorn in the microwave underway.

Regards,  John

John Clark

SV Annie  SM37

St. Augustine FL......awaiting new microwave....

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