Depth Transducer repeatedly overloaded our D.C. panel during a soft grounding- weird!

[David Hughes]

So last week during a negative tide we ran aground in the middle of the Calda Channel outside Key West. Even TowBoatUS got stuck, so we were left for about 4 hours waiting to refloat. Shortly after grounding our transducer, located in the port hull of our cat, began humming pretty noticeably and within 20 minutes or so, all the D.C. on the boat died at once. I learned that I could restart everything by flipping the main D.C. Breaker off then on, but it would fail again every 20 minutes or so. Once we floated free, I ran the boat fine for another week, and the problem never reoccurred.

I thought I'd mention it, as this was certainly a new phenomenon to me.

In hindsight, I suppose I could have flipped off the Instrument breaker to see if that would have killed the transducer too.

[boatbod]

I cannot see how a depth transducer could have tripped your dc breaker. If that much current flowed the wiring would have burned up long before a main breaker.

[David Hughes]

Originally Posted by boatbod

I cannot see how a depth transducer could have tripped your dc breaker. If that much current flowed the wiring would have burned up long before a main breaker.

I agree, but it was for sure the transducer humming loudly, and the failure never happened again in 10 more days at sea. The only variable is the running aground and the humming while aground. So odd.

[transmitterdan]

I guess something else is the cause of the trip. The transducer "humming" is possibly a byproduct of the low DC voltage caused by the high current draw somewhere else. A transducer is an acoustic device. If it is switched on and off rapidly it could "hum" but that in and of itself does not indicate any fault.