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Yesterday while cruising at 15kts we started hearing a huge racket up in the bow area. After investigation it turned out to be the bow thruster was running continuously pushing the bow to port. Neither thruster control (upper or lower) was turned on, and working the on - off switches or joy sticks had no effect. The thruster kept running, and very noisily.
I ended up turning off the battery switch, then removing the in line fuse to stop it from running. Needless to say the thruster motor and power feed wires were quite warm.
I haven't done any troubleshooting yet, so have no idea what is wrong. There was a very small amount of water (1/4 cup) on the floor next to the thruster motor. Perhaps some water shorted the circuitry.
Firstly you can blame the installer for not installing an isolator in the control circuit (very dangerous). You would have just had to turn off the switch if that was the case.
The control circuit excites the solenoid (relay) on the front of the motor. If the control wires short or the panel then the only way to shut off the thruster is by doing what you did. This can also happen by a solenoid sticking (welding).
Take the cover off the motor and inspect the relay with a flashlight. Make sure the contacts are clean and on the bottom. One may be stuck.
If you look at the spade fittings on the relay you will find that one of the control wires jumps to both sides. This is your common. There will also be two different color wires on each side of the relay. These determine the motor direction. You should trace back from this point and disconnect the control panels. Once disconnected turn back on the power. If the thruster comes on it is the relay or possibly some sort of control box (not that familiar with (Engbo/ Volvo). If not I am sure you can figure out which panel failed.
PETRAFIED - 8/18/2008 12:28 PM
Firstly you can blame the installer for not installing an isolator in the control circuit (very dangerous). You would have just had to turn off the switch if that was the case.
Petrafied... Thanks for the very helpful reply. I just purchased the boat and the surveyor wrote this up in his report and I haven't got to that yet. I have to put some kind of switch in. I am really thankful that this didn't happen while the boat was sitting at the dock with no one around.
I'll pull the cover off next time I'm at the boat and see what I can see.
I'm going to really miss having a working thruster. The boat is a single IB diesel downeaster, I have very little clearance between myself and my slipmate, the current really rips through our marina, and I'm not that good at handling the boat yet :-)
door #3...same thing happened to my downeast boat.I got out of it easy(thank you!!)It turned out to be just a loose connection at the switch;though it took a couple hrs.of work to locate the problem.
P.S.when I got my boat,a very experienced captained and downeast owner said to me
"learn how to handle your boat without the thruster in the event it fails"....
PETRAFIED - 8/18/2008 12:28 PM
Firstly you can blame the installer for not installing an isolator in the control circuit (very dangerous). You would have just had to turn off the switch if that was the case.
Petrafied... Thanks for the very helpful reply. I just purchased the boat and the surveyor wrote this up in his report and I haven't got to that yet. I have to put some kind of switch in. I am really thankful that this didn't happen while the boat was sitting at the dock with no one around.
I'll pull the cover off next time I'm at the boat and see what I can see.
I'm going to really miss having a working thruster. The boat is a single IB diesel downeaster, I have very little clearance between myself and my slipmate, the current really rips through our marina, and I'm not that good at handling the boat yet :-)
Depends on the size of thruster but if is under 300A the Blue seas unit is not that expensive. It is just a remote controlled battery switch.
PETRAFIED - 8/18/2008 12:28 PM
Firstly you can blame the installer for not installing an isolator in the control circuit (very dangerous). You would have just had to turn off the switch if that was the case.
Petrafied... Thanks for the very helpful reply. I just purchased the boat and the surveyor wrote this up in his report and I haven't got to that yet. I have to put some kind of switch in. I am really thankful that this didn't happen while the boat was sitting at the dock with no one around.
I'll pull the cover off next time I'm at the boat and see what I can see.
I'm going to really miss having a working thruster. The boat is a single IB diesel downeaster, I have very little clearance between myself and my slipmate, the current really rips through our marina, and I'm not that good at handling the boat yet :-)
Depends on the size of thruster but if is under 300A the Blue seas unit is not that expensive. It is just a remote controlled battery switch.
So we're just talking about a standard battery switch ?
Right now the thruster is wired into the main (and only) bank of 2 8D batteries. I have to shut down everything to shut down the thruster. I'd like to give it its own starting battery. There is plenty of room for a battery within a foot or two of the thruster, but it is under the V Berth where there is no ventilation. If I put it elsewhere it will be further away and subject to voltage drop...
PETRAFIED - 8/18/2008 12:28 PM
Firstly you can blame the installer for not installing an isolator in the control circuit (very dangerous). You would have just had to turn off the switch if that was the case.
Petrafied... Thanks for the very helpful reply. I just purchased the boat and the surveyor wrote this up in his report and I haven't got to that yet. I have to put some kind of switch in. I am really thankful that this didn't happen while the boat was sitting at the dock with no one around.
I'll pull the cover off next time I'm at the boat and see what I can see.
I'm going to really miss having a working thruster. The boat is a single IB diesel downeaster, I have very little clearance between myself and my slipmate, the current really rips through our marina, and I'm not that good at handling the boat yet :-)
Depends on the size of thruster but if is under 300A the Blue seas unit is not that expensive. It is just a remote controlled battery switch.
So we're just talking about a standard battery switch ?
Right now the thruster is wired into the main (and only) bank of 2 8D batteries. I have to shut down everything to shut down the thruster. I'd like to give it its own starting battery. There is plenty of room for a battery within a foot or two of the thruster, but it is under the V Berth where there is no ventilation. If I put it elsewhere it will be further away and subject to voltage drop...
No an isolator or remote controlled battery switch is basically a solenoid that is installed between the batteries and thruster. Often there is a control wire that can be used in the switching circuit however if there is not you will just have to run small switching wire to the helm and install a seperate switch or thru the breaker panel. If you are looking for wiring instruction/schematic the manufacturers site is engbo.no. They have PDF that can be downloaded. I did not look at the QL site but I am sure they have them up as well. Good luck.
Had the same thing happen on the same QL thruster. There is a small relay box remote from the thruster. It hates moisture. You will have to replace the relay control. I bought a tuperware butter container, installed the relay therein and siliconed it tight. It was just a light spray while washing the bilges that took this one out. It started running all by itself hours later.
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Baitkiller= Accredited Marine Surveyor
Bait fear me, fish just laugh.....
The little Dutch boy was just buying time... www.southwestfloridamarinesurvey.com
Had the same thing happen on the same QL thruster. There is a small relay box remote from the thruster. It hates moisture. You will have to replace the relay control. I bought a tuperware butter container, installed the relay therein and siliconed it tight. It was just a light spray while washing the bilges that took this one out. It started running all by itself hours later.
Sounds about right. The sad thing is that relay box was just replaced 2 months ago. The survey found that the thruster only went to STBD so we listed that as something that had to be fixed prior to closing. They fixed it but it took forever because the part had to be sent from Norway. Hope I can get one in the USA...
I was going to say forget it I dont know but since you mentioned the part being from Norway.... There is a brand of controls called side thrusters that had major problems. They are made in Norway. They were recalled. Almost every boat we had in had a bad control. Bayliner kept installing recalled units for a long time. Possibly there is some similarity between QL and sidethruster?
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Top Gun 1992 Donzi 22 Classic 454 King Cobra
I was going to say forget it I dont know but since you mentioned the part being from Norway.... There is a brand of controls called side thrusters that had major problems. They are made in Norway. They were recalled. Almost every boat we had in had a bad control. Bayliner kept installing recalled units for a long time. Possibly there is some similarity between QL and sidethruster?
Well, with 2 failures in a short time on one boat, it does make you wonder.
That may one of the best things you could do right now. A dedicated battery bank is very important to the performance of the thruster and to the integrity of the system as a whole. Its problems like these that can cause havoc with the rest of the boat if the system is not isolated. After that an automatic battery switch or a remote controlled switch is the ideal set up. You need to have control over a system with that much potential energy. One other thing - not knowing how long that thruster was running while underway, I assuming a good long time if the cables were hot, there is a chance there could have been damage to the drive leg. Once the electrical correction has been made be cautious in using it again for the first time. Just bump it a little and listen for anything that seems out of the ordinary. When a thruster is run out of the water it overspeeds the gear box, by as much as 300% in some cases. Drive legs don't deal well with that.
If the control boxes are so much trouble I would either use a Max Power or side power controller with one of their switches or just hard wire the relay and get rid of the controller box. All they do is delay the port to Starboard switching and a few other useless options.
That may one of the best things you could do right now. A dedicated battery bank is very important to the performance of the thruster and to the integrity of the system as a whole. Its problems like these that can cause havoc with the rest of the boat if the system is not isolated. After that an automatic battery switch or a remote controlled switch is the ideal set up. You need to have control over a system with that much potential energy. One other thing - not knowing how long that thruster was running while underway, I assuming a good long time if the cables were hot, there is a chance there could have been damage to the drive leg. Once the electrical correction has been made be cautious in using it again for the first time. Just bump it a little and listen for anything that seems out of the ordinary. When a thruster is run out of the water it overspeeds the gear box, by as much as 300% in some cases. Drive legs don't deal well with that.
Thanks for the advice. I'll definitely put in a dedicated thruster battery. My only question is where to locate it. There is LOTS of room near the thruster in the compartment under the V Berth, but there is very little ventilation there. The compartment is as big as the whole V Berth and I don't really store anything there because it is damp. Does having lots air volume mitigate the lack of positive ventilation for the battery ? The other alternative is to put it much further away and have a long power cable run. I don't like that idea because of the potential for voltage drop.
I hear you on the potential damage front. I'd say the truster was running for at least 3 minutes before I figured out what was making the racket, and how to make it stop. We did stop the boat right away which meant that the thruster was not running dry for that whole time. I'll take it easy when I fire it back up.
Would a sealed gel type battery need ventilation? I don't think so[img]../images/emoticons/confused.gif[/img]I was going to mention it earlier.[img]../images/emoticons/wink.gif[/img]
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Any Port in a Storm!....currently seeking shelter.
A dedicated battery bank is not necessary on smaller vessels 45' and under unless you have electronics/electronic controls on the bank, assuming the ah rating is acceptable. Most views of having to put the batts at the thruster have changed since most builders are running a seperate circuit to the relay and not jumping the control circuit off the power circuit. By doing this you are eliminating voltage drop issues at the relay. This was a failure point years ago.
If your failure was due to low voltage I would seperate the circuits. If you feel your bank is not sufficient add a battery but adding a lump of lead in the bow and another charge lead doesn't make sence.
If your bow thruster fails, just crawl down there and turn it by hand like they did in Speed 2 the movie. It worked on a huge cruise ship thruster (in the movie)! Worst scene in any movie! No, worst movie of any movie!
Possesed Bow Thruster
