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Anyone ever have a problem with...

Guest Contributor

Anyone ever have a problem with a bow thruster charger breaker turning off after a couple of minutes.  This has been happening on my 40 MY.  Any suggestions?




Guest Contributor
Check for loose battery connections which can increase amperage draw and trip breakers. An internal short in the thruster battery can also cause charging problems.

Rising Contributor
The electric bow thruster is intended for usage as low-duration short bursts, not continuous usage of several minutes.

Either switch to a hydraulic bow thruster, driven by the generator PTO, or start docking w/o the thruster, so it may then be eventually added as-intended for short bursts.

Guest Contributor
I appreciate all of your comments. Fwebster, you're comment is particularly helpful. I will check the batteries.
Wingless, maybe it wasn't clear, but the problem is not from over using the thruster, it is when the boat is docked and the bow thruster charger switch is turned on. I have been around the nautical mile a few times and know very well to use in short bursts. Using it longer will not trip the charger switch but will run the battery down quickly.

Rising Contributor
There are several ways to investigate the problem.

What is the bow thruster charger mfg and mfg model number?

My preference would be to measure the AC input current to the charger and the DC output current from the charger, using either a clamp-on or a shunt ammeter(s), to determine if those currents are appropriate or excessive. A fall-back, if those measurement tools are not available would be to use the panel ammeters, on the AC Distribution Panel and on the Charger front panel.

A 15A breaker is specified to sustain that rated current indefinitely and currents exceeding the rating for shorter times, as the current increases. (That is the simple explanation.)

If the currents are good, not excessive, but the breaker still trips, then I would suspect the breaker.

The next step is "easy" and no cost. Swap a known working breaker that sustains a similar load w/o problems into the bow thruster location and put the suspect breaker into the other location to see if the problem follows the breaker.

Kill the AC power feed to the boat and kill the generator prior to touching the AC wiring, to ensure follow-up forum updates are possible.

Breakers are known to get funny w/ age. (The local comedy club has a show this weekend featuring retired breakers.)

If the breaker is bad, replacements are readily available.

Guest Contributor
wingless, these are great suggestions. I will follow up with my technician and give him this. Let you know how it goes.
Thanks and have a great Labor day weekend. Hopefully on the water.