Fuses in the converter wiring harness

[fc3]

Sea Ray installed 30 ampere fuses in the wiring between the converter and batteries. On occasion, despite the charger being rated for only 30 amps, I have found these fuses burned out. Since the fuses are a weird size, they're not common. It's also a pain when the stupid fuse burns out that I invariable forgot to replenish the supply the last time I used the last one.

Also when the converter is supplying a large amount of current, the fuse holders get pretty warm. Not hot enough to be a problem, but warm enough that I know the resistance in the circuit is more than it should be.

Yesterday, the fuse to the port battery bank burned out again. Finally got tired of this situation and installed a nice surface mounted breaker from Blue Sea systems. Don't know why Sea Ray installed in line fuses in the first place. The charger circuit is pretty important.

These are the in-line holders.

These are the improved circuit breakers.

Recommended upgrade if you have fuses in your charger's wiring harness. The Blue Sea breakers are quite nice quality, btw.

Best regards,
Frank C

 

[Nehalennia]

Great write up Frank. What charger do you have?

 

[Larry]

Frank,

Nice upgrade, I last year had one of those fuses keep blowing on me (Finaly isolated it to a bad battery), and not to mention getting those fuses can be a challenge.

 

[fc3]

It's a Pro Mariner, Todd. I don't remember which model.

 

[daven5735]

Good post. I just went through a complete re-do of that circuit including new connections and fuses due to the same issue of not knowing when the fuse blew.

A couple of things. First, the fuses are FNM (Fusetron) 30 amp and are commonly found at Home Depot and hardware stores. I think they cost around $7.50 for a package of two. I do agree there counld be a better alternative like your breakers, however I do have a question: How far away were your fuses (and subsequent breaker install) from the batteries? They should actually be as close to the batteries as possible and not just in a convenient location in the circuit. As much as I like Sea Ray boats, I have found mistakes in wiring configuration and connection quality.

 

[fc3]

Not that you can tell from the photo, but the wiring is quite close to the crossover solenoid, to which they are connected. It's an acceptable location. To be really 100% safe, Sea Ray could have installed 300A fuses at the battery posts...

 

[daven5735]

That's exactly my point. I've got mine 6 inches from the battery post. I've also just installed a new Pro Mariner charger and think that I'm going to spring for their monitor which simply plugs into a connector on the charger and gives you individual bank status. My problem all along has been not knowing what is going on with the port bank. Sure, I have the volt meter at the helm when the engine is running. The starboard side (house, starboard engine and generator on two batteries in parallel) has the volt meter on the main DC panel in the cabin. Having one digital display device I can access from the helm whether the engines are running or not seems convenient.

I'm wondering why the set-up on my '99 310 is different than on your '99 330?

 

[fc3]

Darned if I know. Sea Ray did different things on different boat. Major stuff is similar, but the details can be different. I've seen minor differences between 330s. Guess it depends on the guys who did the work that day. Boats are largely hand made. ISO 9002 means the process is the same, but not necessary the final result.

Best regards,
Frank