Mastervolt Charger/Inverter Combi Replacement 2019

Money Money Money

You know that thing where they say B.O.A.T. stands for "Bring Out Another Thousand". Well this time its two grand :-(.

We powered up the boat from shore in Poole just before making a longer trip to France and ... bad electrical smell from the engine bay...  and bang... that is the end of the 12-2000-100 Mastervolt Mass Combi inverter/battery charger.

It's dead. Really dead. The charger does not work and turning on the inverter makes nasty overload noises and dims the lights! Not good. Turn that all off! Now!

The unit was installed from Grace's beginning and so is 12 years old. Mastervolt have a fixed price repair service (£450) but only if your gear is 10 years old or younger and then you have to send it away. This was no help to us on either criteria.

Identical Physical Layout

Aquafax are the UK Mastervolt distributer back in Hamble and had the replacement/updated 12-2200-100 in stock. All the UK online resellers lie about having stock (I called them all). We were returning late on Friday to Hamble and Aquafax are open Saturday mornings. As we were planning to leave on Sunday for France, we decided to bite the bullet and buy the new one direct from Aquafax. The "bird in the hand" and all that.

The swap out and exchange took me 3 hours with a bunch of back bending in the engine bay. The units are physically identical so it was an easy job assuming a level of competence with basic electrical work. 

Normal issolation precautions were needed here as there is the potential for very high currents in play from the house batteries. The boat isolator solenoid does not isolate the charger and to add a confusion into the mix, Najad had mislabeled the 425A fuse from the Mastervolt, confusing it with the one from the Generator. I of course disconnected both fuses and found this by testing at terminals before working on the gear. Trust no-one and assume nothing is good power electronics practice.