Bad breaker?

[drb1025]

The breaker on the bow thruster has no effect on the circuit. It is always on, whether the breaker is on or off. I thought it must be a faulty breaker. So I turned off the house battery switch at the breaker panel, both engine battery switches, and the house, generator, and inverter switches in the engine room. The thruster was still operational. What's going on here? Any ideas?

 

[RT Firefly]

Greetings,
Mr. drb. The only thing that comes to mind is that the thruster is wired directly to one of the batteries. Have you traced out the wires?

 

[drb1025]

Yes, it is wired directly to its own battery, with no battery switch. That's why it continues to work with all other battery switches off. The fuse is intact. It has to be the breaker then. Agreed?

 

[Bacchus]

drb...

You should be able to check whether you have V in & out of breaker w/ breaker on & off...if so it would confirm the breaker isn't working but I'm guessing that's unlikely?

I'm assuming you are running the thruster w/ controls at the helm(s) - need to do some tracing so find out where the control (lo amp) is fed from - which batt'y bank & thru breaker or not?

Do you know - Was thruster & dedicated batt'y were original equip or added later?

Is it possible original installation was thru the breaker and PO change it to another source - possibly back to the thruster batt'y and didn't utilize the breaker for circuit protection?

 

[RT Firefly]

Greetings,
Mr. drb. Whoops, shouldn't have answered. My knowledge of electrics is limited at best. Apologies sir.

 

[ulysses]

When you say "it is always on" do you mean the bow thruster is on like running or that there is always power being supplied ? There may also be a control circuit that the breaker is being used on that opens or closes low voltage relays to activate the thruster.

 

[drb1025]

drb...



You should be able to check whether you have V in & out of breaker w/ breaker on & off...if so it would confirm the breaker isn't working but I'm guessing that's unlikely?



I'm assuming you are running the thruster w/ controls at the helm(s) - need to do some tracing so find out where the control (lo amp) is fed from - which batt'y bank & thru breaker or not?



Do you know - Was thruster & dedicated batt'y were original equip or added later?



Is it possible original installation was thru the breaker and PO change it to another source - possibly back to the thruster batt'y and didn't utilize the breaker for circuit protection?

I will check the voltage tomorrow. Yes, I run the thruster from the helm joystick control. The thruster is original equipment. The breaker previously worked so I suspect that is the problem. Until I traced the wiring, I was concerned that no battery switches would shut it off. But it has its own dedicated battery.

 

[drb1025]

When you say "it is always on" do you mean the bow thruster is on like running or that there is always power being supplied ? There may also be a control circuit that the breaker is being used on that opens or closes low voltage relays to activate the thruster.

It always has power to the circuit, whether the breaker is open or closed. The thruster is not running.

 

[drb1025]

Greetings,
Mr. drb. Whoops, shouldn't have answered. My knowledge of electrics is limited at best. Apologies sir.

No, it was your suggestion to trace the wires that narrowed the problem down.

 

[psneeld]

Sure the thruster isn't hardwired to a solenoid and the breaker just feeds the switch that poweres the solenoid?


A common type install...

 

[boatpoker]

Check for continuity across the breaker in the off position. If you have continuity across the breaker when "off", then its the breaker.

 

[rwidman]

The breaker on the bow thruster has no effect on the circuit. It is always on, whether the breaker is on or off. I thought it must be a faulty breaker. So I turned off the house battery switch at the breaker panel, both engine battery switches, and the house, generator, and inverter switches in the engine room. The thruster was still operational. What's going on here? Any ideas?

Without getting into how things are wired or should be wired and without telling you to do things that you may not understand, do this:

Turn the breaker off and try the thruster. Does it still work?

If so, disconnect the cable on the "load" side of the breaker. The cable that goes to the thruster or contactor, not the one that goes to the battery. Does the thruster still work? If not, the breaker has failed and needs to be replaced.

If the thruster still works with the cable disconnected, find yourself a good marine electrician because something is not right.


BTW: We're talking about a 60 amp or so breaker here, not a fifteen or twenty amp breaker.

 

[Bacchus]

BTW: We're talking about a 60 amp or so breaker here, not a fifteen or twenty amp breaker.

Respectfully Disagree -

I doubt the hi amp thruster wiring would be run back to breaker panel - especially when drb stated the "fuse is intact" - fairly common practice to protect the hi amp wiring w/ a fuse and it's more likely 200 - 500 amp rated?!

Breaker would more likely feed the lo amp control circuit to operate the control / solenoid circuit... IMHO

 

[rwidman]

Respectfully Disagree -

I doubt the hi amp thruster wiring would be run back to breaker panel - especially when drb stated the "fuse is intact" - fairly common practice to protect the hi amp wiring w/ a fuse and it's more likely 200 - 500 amp rated?!

Breaker would more likely feed the lo amp control circuit to operate the control / solenoid circuit... IMHO

You are correct that the overcurrent protection would likely be much higher than 60 amps. My mind apparently wandered to a windlass.

This leaves me confused as to what the OP is really talking about. It's extremely difficult to fix things over the Internet when you can't actually see for yourself.

I doubt a circuit breaker for the control circuit would fail in the closed position but anything is possible. Maybe the best advice to offer would be to have a marine electrician diagnose and repair the problem. Certainly anything that still works with the circuit breaker turned off is a danger.

 

[Xsbank]

Cue the rude remarks about bow thrusters (just kidding).

 

[Bacchus]

This leaves me confused as to what the OP is really talking about. It's extremely difficult to fix things over the Internet when you can't actually see for yourself.
.

Now we agree completely!

 

[High Wire]

60 amp breaker could be the windlass or a dinghy hoist. A small thruster would use 300+ amp.
Its also possible the 60 amp is a means of charging the separate thruster bat.

The control circuit would be 10 amps or less.

 

[seadogmike]

Respectfully Disagree -

I doubt the hi amp thruster wiring would be run back to breaker panel - especially when drb stated the "fuse is intact" - fairly common practice to protect the hi amp wiring w/ a fuse and it's more likely 200 - 500 amp rated?!

Breaker would more likely feed the lo amp control circuit to operate the control / solenoid circuit... IMHO

I agree. This sounds most logical.

 

[drb1025]

To close this thread, it turns out that the breaker works but is not wired to anything. The thruster and the joysticks are wired directly to the battery. I assumed the breaker that is labeled "bow thruster" was in fact connected to it. I would turn it on before using the thruster and off when I left the boat. At some point I realized it had no effect on the thruster operation, and thought there was a problem somewhere. I don't know why there is a breaker for it, perhaps just a standard panel with this label, much like the labeled breakers for dishwasher and disposal, neither of which I have. Nonetheless, mystery solved.

 

[boatpoker]

Strongly suggest you wire the thruster through the breaker or at very least a battery switch that you can turn off. I once witnessed a boat do tremendous damage to itself and neighboring boats when the thruster solenoid welded itself in the closed position and the thruster would not shut off or change direction when backing in to the slip. This condition will not blow a fuse until the thruster overheats.

 

[drb1025]

Good point that I forgot to address. I am adding a battery switch so I can shut the thruster off if it malfunctions.

 

[FF]

" It always has power to the circuit, whether the breaker is open or closed."

DC is very hard on circuit breakers, as the current will frequently create a spark when broken.

Sounds like yours is melted closed , just replace it.

THe DC problem with big DC is a well known problem and why many folks will use a class T fuse in high draw circuits.

 

[rwidman]

Sounds like yours is melted closed , just replace it.

That's what we call "throwing parts" at a problem in an attempt to troubleshoot it. Disconnect one wire and if the problem remains, it's not the breaker. $30 plus a trip to the store saved.

 

[FF]

"That's what we call "throwing parts" at a problem in an attempt to troubleshoot it. Disconnect one wire and if the problem remains, it's not the breaker. $30 plus a trip to the store saved. "

The poster already stated,

"It always has power to the circuit, whether the breaker is open or closed."

What will more "testing " do?

 

[psneeld]

hard to believe the breaker is being backfed...but possible.

without finding out where power is present through the whole system, tough to figure out which component is faulty.

 

[rwidman]

"That's what we call "throwing parts" at a problem in an attempt to troubleshoot it. Disconnect one wire and if the problem remains, it's not the breaker. $30 plus a trip to the store saved. "

The poster already stated,

"It always has power to the circuit, whether the breaker is open or closed."

What will more "testing " do?

It will determine if the breaker is defective. If it's not, replacing it, as you suggested, would be a waste of time and money.

 

[drb1025]

hard to believe the breaker is being backfed...but possible.

without finding out where power is present through the whole system, tough to figure out which component is faulty.

I had an electrician look at it. No faulty components. The breaker isn't being used. The thruster and the joystick controls are wired directly to a dedicated battery. I need to add a battery switch in case of malfunction.

 

[rwidman]

Yes, it is wired directly to its own battery, with no battery switch. That's why it continues to work with all other battery switches off. The fuse is intact. It has to be the breaker then. Agreed?

Nope. What is the rating of the breaker? If it's just a 15 or 20 amp breaker in your electrical panel, it's just for the control circuit and contactor. The actual thruster cables are protected by the fuse.