Breakers tripping

[Miss Jamey Lynn]

I have a 1975 classic Hatteras motor yacht and a couple breakers want to trip when under a regular load I think I need to replace them I'm thinking of getting new ones from Sam's because they're not normal circuit breakers is this a normal experience with old circuit breakers or should I be looking for something else

 

[rustybucket]

I have a 1975 classic Hatteras motor yacht and a couple breakers want to trip when under a regular load I think I need to replace them I'm thinking of getting new ones from Sam's because they're not normal circuit breakers is this a normal experience with old circuit breakers or should I be looking for something else

While breakers can go bad or get weak, I'd probably suggest clamping an amp meter on the wires and see what the circuit is actually pulling. Breakers are NOT cheap and it sucks to replace them and have the same problem. Verify that the amp pull is actually 'normal' before you start pulling stuff out. Could very easily be bad wiring or bad appliances somewhere.

 

[madhatter1]

Do the same breakers trip on the generator? If not you could have either low voltage or undersized conductors feed shore power. If volts go down amps go up (load is gonna pull load no matter what) and that will trip a breaker that is just doing what designed to do. Not saying that is what it is but something to be verified.

 

[SEVEN]

I’ve only had it happen to me once. But the same circuit kept tripping and tripping and tripping. I did contact Sam’s and order a new one and that seems to have taken care of the issue for the last five years.

 

[Pascal]

Which breaker ? Individual circuit or a master ? Have you checked the load on the circuit? What was on?

Yes it could be the breaker but it could also be an issue on that circuit.

 

[Photolomy]

I second everyone's thoughts that a bad breaker is usually not the issue. I had a breaker that would open whenever I would run the water heater, but only on shore power. Turned out that the PO had put in a 2000 watt element instead of a 1500 watt element (which is what the WH was designed for). In any event, the 2000 watt element put the amps right at the threshold and the breaker would open at my dock, but not at the PO's dock, nor while on generator. I replaced it with a 1500 watt element and all is fine. Short version, before you replace the breaker, confirm that it is broken.

 

[Photolomy]

Another tidbit that I learned from that ordeal is that breakers are designed to stay closed with 80% of their load. For example, a 20 amp breaker can carry 16 amps all day, not 20 amps. It can handle surges to 20 amps, but only briefly. My WH would stay on for 15 seconds or so, then the breaker would open.

 

[madhatter1]

Another tidbit that I learned from that ordeal is that breakers are designed to stay closed with 80% of their load. For example, a 20 amp breaker can carry 16 amps all day, not 20 amps. It can handle surges to 20 amps, but only briefly. My WH would stay on for 15 seconds or so, then the breaker would open.

That is exactly how they work.

 

[SKYCHENEY]

Also, if this is a breaker that is a master feeding a ships service panel, it may be set up as a ground fault. I know that the 1978 boats had this, not sure about 1975. IF you have the white breakers next to the four pole ships service breakers, then that is a ground fault and those do go bad.

 

[Miss Jamey Lynn]

Thanks for the responses,good info

 

[luckydave215]

To date I've replaced three on my boat. They DO get tired, but I second the previous advise to make sure it's actually the breaker.