Balmar Regulator Blowing Fuses

[cruiser_pete]

I have a new Balmar mc-614 regulator in a brand new boat. The 10A power fuse keeps blowing. Balmar has instructed the dealer to replace the fuse a number of times. Finally, Balmar has said that they have seen this before, and the 10A fuse should be replaced with at 15A fuse.

Has anyone heard of this? Should I be concerned that this is a device designed for 10A protection and now it is protected with a 15A fuse?

[Hywel]

I have the same problem, the Balmar Regulator keeps blowing the 10A fuse. Apparently the fused wire powers the box and only needs a fraction of an amp. I had the alternator re-wired to the regulator. Nothing wrong with the previous wiring was found, and the problem persists. It seems to occur when the bow thruster is used and I noted that the Cristec's dedicated alternator sense connection is in fact connected to the engine battery. However this shouldn't explain why the Regulator demands more than 10A.

[Maine Sail]

The MC-614 is capable of a max short duration output of 20A to the field and 15A continuous. The fuse protects the wire so ideally all MC-614's should have a 20A fuse but for most applications a 15A will be fine...

In most installations (small case alternators) the MC-614 will not need to deliver more than about 6A - 8.5A but for some alternators they can use upwards of 12-15A on the field for short durations. When you kick in a thruster and pull battery voltage down you can briefly demand more field and blow a 10A fuse rather easily......

[Hywel]

That's extremely helpful and Balmar have confirmed that a 15A fuse is okay. I have a 160A alternator which obviously requires more than 10A when using the Bow Thruster at tick over. Thank you Maine Sail.