Main Breaker Replacement

[jfmagana]

I've got an intermittent problem that I believe is due to a bad ground, so I started from the batteries and cleaned all of the connections I could up to the chartplotter which is showing the issue. Not surprisingly, there was some corrosion on the battery connections, the main ground stud, etc.. I did take the cover off of the main 40A circuit breaker (you know, that white cover with the red reset button that is marked "40") and found that the connections were completely corroded. Corrosion was so bad that I could not remove the screws (they were completely rusted). Anyway, I guess my question is: should I leave this CB alone or put in the effort to replace it? I didn't Ohm-out the CB, but my only thought was that maybe the connections are very resistive now and this could be limiting current through that CB....is this possible or am I crazy? Any advice would be greatly appreciated.

Thanks!

 

[seasick]

I've got an intermittent problem that I believe is due to a bad ground, so I started from the batteries and cleaned all of the connections I could up to the chartplotter which is showing the issue. Not surprisingly, there was some corrosion on the battery connections, the main ground stud, etc.. I did take the cover off of the main 40A circuit breaker (you know, that white cover with the red reset button that is marked "40") and found that the connections were completely corroded. Corrosion was so bad that I could not remove the screws (they were completely rusted). Anyway, I guess my question is: should I leave this CB alone or put in the effort to replace it? I didn't Ohm-out the CB, but my only thought was that maybe the connections are very resistive now and this could be limiting current through that CB....is this possible or am I crazy? Any advice would be greatly appreciated.

Thanks!

It should be replaced if it is that corroded. Failure of these breakers is common.

 

[seabob4]

I really couldn't stand those larger amperage push-button breakers. I prefer the surface or panel mount ones like these...

 

[BobP]

What's the intermittant problem, specifically ?

And yes, get rid of button breaker and use the waterpoof ones above - make sure rating is 40 A though.

 

[seabob4]

What's the intermittant problem, specifically ?

And yes, get rid of button breaker and use the waterpoof ones above - make sure rating is 40 A though.

Bob is correct on the 40A. My pics are for demonstration purposes only... :?

 

[jfmagana]

What's the intermittant problem, specifically ?

And yes, get rid of button breaker and use the waterpoof ones above - make sure rating is 40 A though.

Bob: thanks for asking...two weird problems:
1. On my Floscan gauge, the analog read-out is working fine and is right on target for a given RPM. However, the digital (i.e., "Totalizer") read-out is reading very erratically. Specifically, it climbs some crazy amount (e.g., say >30 gallons in one minute, then reads correctly for a few minutes, then jumps again, etc.).

2. When I engage my Furuno AP, it caused my Furuno chartplotter to reset itself.

I suspect the Furuno is resetting itself because it detects a voltage drop, and I think the Floscan read-out issue is probably due to a bad ground (if it was really engine problem (e.g., like a fuel pump) the engine should sound strange and the analog gauge should show the problem too.

As I mentioned above, I did find that all of the connections to the main ground stud were severely corroded, so I cleaned them until they sparkled, coated them with dielectric grease and put them back together. Just for the sake of completeness, that's when I checked the CB and found it completely corroded. I tried to remove the screws, but they were just solid rust (I have to cut/grind them off). I just came back from West Marine where I bought the 40A breaker you recommended. By the way, should I disconnect the battery cables before changing the CB? Is it wired directly to the battery?

Thanks again!

 

[seabob4]

The 8GA (or maybe 6) lead feeding your breaker should come off the common (switched) post of your battery switch. As long as the switch is off, you'll have no voltage on that feed...

 

[jfmagana]

Thanks very much for the info.!

The 8GA (or maybe 6) lead feeding your breaker should come off the common (switched) post of your battery switch. As long as the switch is off, you'll have no voltage on that feed...