Mastervolt Alpha10A Fuse blows always

[Leukomelon]

Hi,

we have a Mastervolt Alpha Alternator with Mastervolt Alpha Pro Regulator (2016). Until now the Alternator was working fine and putting 100 A into our Lithium Batteries at 1800 rpm of the motor.
At the moment the the 10A Fuse between the battery positive pole and alternator Field connector on the Alpha Pro regulator (No. 10 in the Installation Plan) always blows. If you set the motor at a fixed rpm, the alternator will charge, but as soon as you are changing the rpms on the motor the fuse will blow.
Does anybody have any suggestions? I'm not a good electrician, but unfortunately the marine electricians here in Opua, NZ are all busy...

Thanks a lot,
Goetz

[coopec43]

Is there anything here?


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[Leukomelon]

Thank you coopec43 for your answer.

In the end we measured everything, cleaned every contact and came to no solution. I started building out the alternator to have it bench tested.

While removing all the cables, there was a bunch of cables incl. Field and Battery + sensor in a cable housing zip-tied to the alternator. They chafed through and with Bat + touching the housing of the Alternator it blew the fuse. It just didn't always touch the housing directly but just with at a certain amount of vibration of the motor.

Luckily, its and easy and cheap repair.