Sunday, April 3, 2011

Initial Mastervolt install....

Amongst the numerous half finished projects on-board is the DC distribution install. The Mastervolt people have been great in replying to my myriad of questions. So far I love the MV system. The great (and possibly only) benefit of wiring your own boat is that you should know how everything works. The problem is that, despite having read most of the books, there are still gaps in my understanding of electrickery. I will have a qualified grownup check everything before it goes live.

This is the distribution diagram for the system, so far;

One interesting element of the layout is that the house batteries are linked to the Mastershunt 500 via a switch. All the loads, Combi charger, alternator etc. are linked into the DC Distribution 500 and then, via the Mastershunt 500 to the House batteries. If the switch is off the house batteries cannot be charged. I'm not sure if this is an issue or not.

Basic wiring;


Ocean Dove said...

I have all the Battery charging sources (Alternator, Solar, Charger) connected directly to the House battery each source is fused. The Solar panels and invertor/charger can be switch off so they will not give a false reading to the alternator voltage regulator.
The main reason I have the alternator connected directly to the batteries is to prevent damage to the alternator. When the charging amps from the alternator have not place to go the diodes or windings in the alternator can be fryed.
just my 2.03 cents (US)
(The Canada dollar is great)

Ocean Dove said...

Are your DC battery switches behind the ladder under the companionway?
Are you concerned about water coming in the companionway onto the switches and wiring?
Ocean Dove had the old Freedom inverter install there but no switches. When the inverter failed there was evidence of corrosion on the circuit boards.
That is why I moved the inverter into the engine room.

The Incredible Hull said...

Thanks OD, I was hoping you would chime in. Second question first. I will have the whole install covered by perspex, with access holes cut for the switches. A splash guard, along the top, will protect switches.

The Incredible Hull said...

I have the Alt, solar and wind (if installed) all going to a single bus and then through the DC Distribution 500 to the shunt. The thing is that they have to go the shunt to get "counted". The main alternator source wire will lead to an isolating diode and then to both the engine battery and house "bus". I will be using a smart regulator to deal with the normal undercharging problem associated with isolation diodes. This will prevent me frying the alternator if the house bank is off. Keep the comments coming.

Vidmantas said...


well if this issue is still not dead i can see one at least one mistake at your system instalation

MasterShunt should be connecter on the other side on DC distributor

then holding distributor inthe way that two mounting holes are below - shunt must be on the left side

and because they connect witk mastesconnect i asume that your shunt is connected in reverse also

i am working for boat building company and we starting to use mastervolt systems - i am not an expert on the system but for now i gathering all information i can find

The Incredible Hull said...


Thanks for that, that is very interesting. Edward S. The MV tech expert said that it was not an issue. ("*yes the shunt can be revered in the set up - to allow power to come in the other side")

However, when I have a charger switched on I get a MINUS reading on the easy view which I thought was curious. Can you drop me an e-mail at whitby42 at, I would love to pick your brain.