Negative Busbar connection...

[V1701]

Evening all,
I'm doing some rewiring which includes a busbar for the negative side of the domestic circuit. Is it best to also connect the busbar to the engine as well as to the domestic battery negative? Boat is Albin Vega (GRP)...
TIA,
David.

 

[VicS]

Evening all,
I'm doing some rewiring which includes a busbar for the negative side of the domestic circuit. Is it best to also connect the busbar to the engine as well as to the domestic battery negative? Boat is Albin Vega (GRP)...
TIA,
David.

Presumably there is a dierct heavy connection between engine and battery to carry starting and charging currents.

Therefore no just make a connection from your busbar to the battery.

 

[V1701]

Presumably there is a dierct heavy connection between engine and battery to carry starting and charging currents.

Therefore no just make a connection from your busbar to the battery.

Thanks Vic

 

[nigelmercier]

Evening all,
I'm doing some rewiring which includes a busbar for the negative side of the domestic circuit. Is it best to also connect the busbar to the engine as well as to the domestic battery negative?

Reasons to not do either:

[1] Your engine may be isolated, so a connection here is a bad thing.
[2] Your isolator switch may be in the negative, so you may need to connect to this instead of the battery.

 

[William_H]

Negatives

As I read the question it is about connecting the negatives of the engine battery and the domestic battery.
Yes these are normally connected with a heavy cable which can carry the starter current. (positive switched systems)
This will facilitate charging the domestic battery from engine and
if you need to use the domestic battery to start the engine or to boost the start battery all you have to do is connect the 2 battery positives together either by switching or jump lead. (be careful with the jump lead as sparks can ignite hydrogen from battery. good luck olewill

 

[rogerthebodger]

When I wired up my new boat I made 4 heavy duty bus bars, 3 positive one for each battery bank and a negative to which the battery negatives and the heavy duty negatives from engine, bow thruster, inverter and a domestic negative bus bar were connected.

The heavy duty bus bars were made from brass strips with 4 off M8 brass set screws threaded in to each.

The domestic bus bar was also brass strip with maybe 20 to 30 of M4 set screws threaded in to it for the connection of the negative of all the low current items, instruments, lights and other control circuits.

I used studs rather than chocolate block type connection block as you can use ring crimp connectors and get more than one wire on each stud.

 

[lw395]

Reasons to not do either:

[1] Your engine may be isolated, so a connection here is a bad thing.
[2] Your isolator switch may be in the negative, so you may need to connect to this instead of the battery.

Good points, the OP should check whether either is the case!

I have seen some odd things done in yot wiring, which makes me loathe to advise at a distance, unless it's a great distance....