"House Charging" breaker keeps tripping above 1000 rpm

dspan

Hi Everyone,

I have a weird problem.  2007 Rinker 350 EC, MAG350s.  For some reason, when I am running over 1000rpm or just about anything above idle, my "house charging" breaker trips.  The breaker is located in the main rear DC panel area near the swim platform.  I was cruising around last weekend and suddenly my radio started cutting out and my garmin shutdown.  I plugged in my little DC power meter into the cigarette lighter and it read like 10.9V.  After investigating, I noticed the "house charging" breaker was tripped.  I reset it and the alternators brought the voltage up to around 12.4V at idle.  When I started to increase the throttle, the voltage increased to around 13.2v which is about normal for my boat when I am cruising through no wake zones around at 1200rpm, then I heard a "click" from the rear panel and the breaker had tripped again.   I haven't changed anything, and it was running fine all year.  It is still running great but I can't really charge my boat from the alternators anymore.  Not even sure where to start with this one, hope you guys have some ideas.

Thanks in advance!

Black_Diamond

If the batteries are lead-acid, make sure they are filled with water as a start. If they are dry, they are likely ruined. 

MarkB

My guess is your alternator is kicking in at those rpms (1000) and your isolator is gone so it's pushing amps back into your battery charger. 

Hamdog

I'm a little confused here. If you are cruising with the engines running, your battery charger will not even be turned on. You will have DC battery power only. There is no breaker associated with charging from the alternators that I know of. Does the breaker say "house charging"? Never seen one.

Was the generator running?

dspan

Black_Diamond said:

If the batteries are lead-acid, make sure they are filled with water as a start. If they are dry, they are likely ruined. 

The batteries are brand new AGM Marine Deep Cycles

dspan

MarkB said:

My guess is your alternator is kicking in at those rpms (1000) and your isolator is gone so it's pushing amps back into your battery charger. 

Hmmm, interesting theory.  I suppose that could be happening but the battery charger only functions on AC power when on shore power or running the genny. In this case I am just putting around.  I assumed the "house charging" breaker was somehow connected to the alternators since it pops when I increase the RPMs

dspan

Hamdog said:

I'm a little confused here. If you are cruising with the engines running, your battery charger will not even be turned on. You will have DC battery power only. There is no breaker associated with charging from the alternators that I know of. Does the breaker say "house charging"? Never seen one.

Was the generator running?

No sir, just the engines.  I am trying to attach an image here.  The "house charging" breaker is in the bank of 4 push button/blade type breakers, top right.E

dspan

Alswagg said:

Check to see how many amps your running through those breakers.  The should be rated for 70 amps.  But if your alternator is sending more or your battery is bad it might be overcharging and tripping.  Or, you simply have a bad breaker    

I am not entirely sure how to check how many amps are running to those breakers.  It is very difficult if not impossible to get at the back of that panel.  Can I get a reading near the alternator?  I assume I need one of those clamp "lobster claw" looking multimeters.  I don't have one but have always wanted one, this could be the excuse I needed.

dspan

Still having this problem.  Boat was launched very late this season so just getting back to it now.  Sleeping in drydock for the winter didn't fix it haha.