Electrical Systems


Lochmarin is fitted with a 24 volt DC system (with a number of 24v/12v dropper transformers where required), a 240 volt 50Hz AC system utilising either shore power via an Isolation Transformer or the onboard 7 kW Northern Lights generator. A 1600w/24V 40 amp Inverter provides AC power from the house batteries when required.

Renewable power is provided by 4 solar panels and a 24 volt D400 Wind Generator providing plenty of power when on passage.

DC System

The 24V DC system comprises two entirely separate unconnected subsystems with the “house system” not connected to the “engine starter system ” thereby ensuring that capacity is always available to start the main engine. A further backup is provided by another 12v system solely used to start the generator. Jumper cables are carried if it is ever necessary to start the main engine from the house batteries.


House system: 4 off 12V 290Ah Rolls AGM batteries connected in series-parallel  providing 580Ah primary capacity at 24 volts (equivalent to 1160Ah at 12 volts)

Engine start system : 2 off 110Ah 12V Marine batteries connected in parallel providing 110Ah at 24 volts exclusively to main engine

Generator start system: 1 off 110Ah 12V Marine battery providing 110Ah at 12V exclusively to Northern Lights generator engine


120 Amp 24 volt main engine driven Alternator exclusively charging house batteries

60 Amp 24 volt main engine driven Alternator exclusively charging engine start batteries

30 Amp 12 volt generator engine driven Alternator exclusively charging generator start battery

Wind Turbine

24 volt Eclectic Energy D400 Wind turbine mounted on pole at transom and delivering 225 Watts at 20 kts via a regulator to the house batteries.

Solar Panels

2 off 12 volt semi-rigid 75 W panels in series on coach roof feeding into house battery system via a ProStar-15 solar charge controller

2 off 36 volt rigid EOPLLY 200 W panels mounted on rotating/sliding rails on cockpit pushpit and independently feeding into house batteries via a BlueSky Solar Boost 3024i 24 volt MPPT Solar Charge Controller

Battery Monitoring System

Victron Energy BMV-600S battery monitoring system installed at chart table and monitoring state of charge, voltages, in and out amperage and many other battery condition parameters.


AC System

The AC system aboard Lochmarin comprises a 240 volt 50Hz system with power provided either from shore or from the onboard 7kW generator. A 1600W Inverter/Charger provides limited AC power to the AC ring main from the house batteries when at sea. Distribution is via an AC switch panel and an RCCD protected 240 volt 13 amp ring main comprising 13 amp UK sockets throughout the vessel.

Shore Power

Shore power is fed via a European 15 amp weatherproof socket into the AC panel via a fully rated Isolation Transformer thereby ensuring that no shore power anomalies in Marina circuits are transmitted aboard and preventing stray currents and their ensuing safety and corrosion problems when in Marina berths.

AC Generator 

Onboard 240 volt 50Hz power is provided by a Northern Lights 7kW diesel generator which is started from an independent ‘black start ‘ 12 volt battery and a separate filtered diesel supply from the fuel day tank. The generator which is located in the engine room within a totally enclosed acoustic housing feeds power to the AC distribution panel. The generator was installed in 2012 and currently has 884 hours runtime on it.

AC Distribution Panel

The AC distribution panel provides feeds via appropriately rated circuit breakers to the following circuits:

  • Hot water Immersion Heater
  •        Victron Energy 1600W/24v/40amp Combination Battery Charger/Inverter
  •        Washing Machine
  •        Victron Energy Centaur 24v/60amp Battery Charger (new 2017)
  •        AC Ring main Sockets
  •        Seafresh Watermaker