Recent Project:
Alternator Replacement

Click for Images

Department: Fabrication
Product Summary: Replace alternator with DC-DC charging capabilities
Boat: Cyrus 80, carbon sailing yacht

Click for Images

After the removal of a broken alternator from this Cyrus 80 with a STEYR main engine, Mastervolt lithium-ion batteries and CZone monitoring system, our yacht electricians got to work investigating the current system and how we could best suit the owners’ requirements on board. What the owner requested was not a standard option available from the manufacturer, so we came up with a customised modification. After researching a possible solution, a visit to the boat to check available space resulted in a complete change of approach. They discovered that the main engine and domestic batteries did not have a common negative, which would be a problem as DC-DC battery chargers are non-isolated. Back to the drawing board.

The final solution was to install an auxiliary alternator with a stainless steel double bracket and two custom made aluminium double pulleys to drive the new alternator with the repaired existing one. Space was very tight in the engine bay, which limited how the modifications could be installed. After concerns that the mounts initially used were not going to be strong enough and there was a risk that the engine block would be damaged, we amended the design to incorporate a lower support arm. This project highlights the benefits of our in-house fabrication department; how the engineers could go back and forth between the boat and the workshop, tweaking the design to achieve perfection. It undoubtedly sped up the process and resulted in the best outcome for the yacht owner.

With the equipment in place, the yacht electricians could get to work running cabling and locating the necessary connections. The addition of the Alpha Pro to regulate the charge to the batteries from the alternator will improve many aspects of the system. The Alpha Pro, from Mastervolt, ensures fast and safe charging, and will monitor the engine load, measure the temperature and voltage of the batteries, thus preventing overcharging. This could then be integrated with the existing Mastervolt and CZone monitoring and control systems on board.