DC2DC negative input/output

[SteveK]

Does anyone know the reason why there is a negative input terminal and negative output terminal.
Manual diagram shows input negative from start battery and output negative to house battery clearly and then shows that both are conected by bonding all grounds and negative DC.

Not a major issue, just trying to understand the need to run two negative lines when it seems one could be split t input and output terminals.

 

[Jeff F]

Maybe it's an isolated charger? Victron makes both isolated and non-isolated. The difference is the switched ground AFAIK.

 

[MYTraveler]

Maybe it's an isolated charger? Victron makes both isolated and non-isolated. The difference is the switched ground AFAIK.

That sounds right to me. I would check continuity / resistance between the two negatives.

 

[mvweebles]

Here's an article from PKYS on Isolated vs Non-Isolated chargers.

https://shop.pkys.com/isolated-non-isolated-dc-dc-charger

Peter

 

[Flatswing]

Is 1 of those a case ground? I am not familiar with the device to which you are referring. My Inverter/charger requires a very large separate case ground back to the DC negative buss.

 

[SteveK]

Here's an article from PKYS on Isolated vs Non-Isolated chargers.

https://shop.pkys.com/isolated-non-isolated-dc-dc-charger

Peter

Thanks Peter, that link answered my question and supported my thoughts that an islolated unit does not need separate negative to source and charge battery since they are already bonded.
The article also wondered why isolated units exist.

 

[SteveK]

Is 1 of those a case ground? I am not familiar with the device to which you are referring. My Inverter/charger requires a very large separate case ground back to the DC negative buss.

Yes my inverter/charger also has a separate ground wire even though it is joined to all the negative wires on the boat. The need for that was well explained to protect inverter should the negative feed become open.

DC2DC chargers are a different animal