Bow Thruster Continues To Run

So during the lighted boat parade last night I was using my thruster off and on to help navigate past docks. Then my wife, who was on the bow, told me that it started to run non stop.

I went and shut off the battery switch and the thruster stopped.

So just now I went down to see if I could work out what was happening. When I turn the switch on the thruster starts up pushing water to starboard. There is no power light on either of the FB or PH paddle controls.

I have looked at the manual for the Side Power SP155TC but the troubleshooting section does not cover continuously running.

At first it sounded like a FB Paddle control issue, but I should still get power and control at the PH.

Any thoughts? Could I have a directional solenoid locked?

I would check for power at the coil of this solenoid:
1) If it's powered with no input from the paddles then there is an issue with the paddle control or whatever energizes the solenoid.
2) If there is no power at the coil but the thing still runs, then the solenoid power contacts are stuck ( welded ) closed ( it can happen )

Just sayn' FB

Contact Imtra. They have excellent Sidepower service and advice.

I'm betting Exsailor's #2 answer is the correct one.
Easy check with meter.

Nice that you had a battery switch to shut it down. That is a winter project for me.

Probably a control solenoid that has fused shut. The only question is whether there is power from the control circuit commanding the closure, or if it's closed all on its own. Measuring voltage across the small wires in the solenoid will answer that question.

Contact points will always heat up when used due to arcing.The OP stated he was using the thruster on and off,which would only compound the heating issue.I have seen many contacts weld themselves when the coil voltage becomes low,causing what is known in the trades as chatter.

drb1025 said:

Nice that you had a battery switch to shut it down. That is a winter project for me.

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I put an isolator switch in the power feed to my bow thruster for just this reason. Mine is powered from a start battery. Having to switch off the start battery, with engine running, to stop the bowthruster is something I wanted to avoid.

My guess is that the relay (contactor) is stuck. You might be able to free it with a good smack with a blunt object ("percussive maintenance") but the better fix is to replace it.

This has come up before. Suggest a master shut-off switch conveniently located.

Same concept. On the Vetus units the large solenoid that sends current to the motor has contact that can fuse together thus providing continuous power to the motor. Normally the power supplied by the joystick solenoid holds down the spring and thus closes the contact. When the contact fuses releasing the power holding down the spring does not release the contact.

We had the exact same thing happen. I posted a thread on the issue, in which I also explained the troubleshooting that was suggested by Imar (sidepower) and the final outcome. http://www.trawlerforum.com/forums/s31/bow-stern-thruster-warning-28020.html

In sum, it is likely the control unit or the solenoid on the motor (as opposed to the switch), but could be any of the three. In our case it was the solenoid. You trouble shoot by turning off all power and first unplugging the joystick. Turn power on and see if it runs. If it stops, then you have a bad joystick. If it keeps running, then you disconnect the control unit. If it stops, the control is bad (this is what the factory said is most common). If it keeps running, then it is the solenoid. During troubleshooting, I wrapped the solenoid with a screw driver handle and it stopped running, so I decided to replace the solenoid. It ran fine with the old one after hitting it, but I didn't want it to get stuck on again, so still replaced. I think the solenoid is the cheapest part of the bunch, for what it is worth.

OK, we have the answer.

And the answer to an additional problem.

Not only did the solenoids fuse but the heat melted the plastic housing on the motor and transmitted down the wires and melted the protective wiring cover to the extent that the rubber sheathing on red and black wires (held together in a sleeve) melted and were touching. We were darned lucky we didn't have a fire.

The motor has been pulled and will either be refurbished or upgraded. The wiring will be replaced and a cut off switch installed easily accessible by the forward bunk instead of having to go into the engine room and use the battery switch.

As I approached the dock when the thruster was acting up the port engine quit. It wasn't a problem because the boat was parallel to the dock and the wind pushed us against the dock. I could not start the port engine the next day, the Glendenning controls were showing a neutral light on the starboard but no neutral light on the port. So obviously the port engine was set in gear. I wasn't sure if it was an engine issue or a Glendenning issue.

So I had a Glendenning guy look at it today. And what a surprise we got.

The controls were purchased and installed by the yard the PO used November of last year. I have all the documentation with the boat. The actuators are 12V. However I am on a 24V system. They installed 12V Actuators on a 24V system. Mechanic said that it was no surprise that they ran OK throughout the year as they would last longer with over voltage rather than under voltage, but eventually the motors in the acuators would give. He believed that the thruster wires touching surged the power through the port actuator and burned the motor.

He pulled both of them and is sending them back to Glendenning. There will be a conversation, but I won't share that here.

Interesting day on board to say the least!

Wow, good catch on both problems.

BTW, does your thruster have a fuse? Those cables melted together should have blown the fuse, at least in theory.

twistedtree said:

Wow, good catch on both problems.

BTW, does your thruster have a fuse? Those cables melted together should have blown the fuse, at least in theory.

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Yes, there is a fuse. The cables were between the fuse and the thruster. Fuse did not blow. Even worse it fed back through the system to the acuator. Issue is a continuously running thruster probably has consistent draw, just heats up. So the fuse would not come into play.

Why it blew the acuator motor I do not know. Though a 12v motor getting 24v might not need much of an additional surge to blow. Plus the fuse might be 50V, I will need to look at that.

It's probably worth checking the wire gauge supplying the thruster, and the fuse rating. If properly set up, the fuse should blow before the wiring overheats. That's it's purpose in life.

twistedtree said:

It's probably worth checking the wire gauge supplying the thruster, and the fuse rating. If properly set up, the fuse should blow before the wiring overheats. That's it's purpose in life.

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Yes, but if the solenoids on the motor are fused and the heat from the motor is transmitting from the motor back along the wire, not sure that the fuse would blow as it is not an amp driven heat.

menzies said:

Yes, but if the solenoids on the motor are fused and the heat from the motor is transmitting from the motor back along the wire, not sure that the fuse would blow as it is not an amp driven heat.

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Humm. Many electric thrusters have thermal shut down built into them. Maybe not yours, or maybe it's not working? If running a thruster continuously creates a meltdown and potential fire, I'd argue there is a design problem. Is the fuse value consistent with what the thruster manufacturer recommends?

Carolena said:

We had the exact same thing happen. I posted a thread on the issue, in which I also explained the troubleshooting that was suggested by Imar (sidepower) and the final outcome. http://www.trawlerforum.com/forums/s31/bow-stern-thruster-warning-28020.html

In sum, it is likely the control unit or the solenoid on the motor (as opposed to the switch), but could be any of the three. In our case it was the solenoid. You trouble shoot by turning off all power and first unplugging the joystick. Turn power on and see if it runs. If it stops, then you have a bad joystick. If it keeps running, then you disconnect the control unit. If it stops, the control is bad (this is what the factory said is most common). If it keeps running, then it is the solenoid. During troubleshooting, I wrapped the solenoid with a screw driver handle and it stopped running, so I decided to replace the solenoid. It ran fine with the old one after hitting it, but I didn't want it to get stuck on again, so still replaced. I think the solenoid is the cheapest part of the bunch, for what it is worth.

Click to expand...

solenoid may welds closed, if power flow low. The battery does not fit, or downloaded low, the wiring connections loose or oxid, wire diameter too small, etc. cause great heat, when the current does not flow, so it is recommended to check and measure power flow, same spray WD or crc wires joint etc.

twistedtree said:

Humm. Many electric thrusters have thermal shut down built into them. Maybe not yours, or maybe it's not working? If running a thruster continuously creates a meltdown and potential fire, I'd argue there is a design problem. Is the fuse value consistent with what the thruster manufacturer recommends?

Click to expand...

Yes, it has a thermal shut down - the mechanic has pulled the motor to send off to Imtra and they will check to see why it failed. He did tell me that there was a small chance that a previous owner could have pulled the override so as to be able to use the thruster for longer periods - which I said was crazy!

The thruster we will deal with. I am more concerned about the acuators - and someone putting 12V into a 24V system. That could have left us completely stranded in the islands next year, or having to disconnect the Glendennings and somehow changing gears manually with someone sitting by the engines to get near to a mechanic.

So while a rear nuisance last Saturday the thruster issue can have resulted in us avoiding a much bigger issue down the road.

The Gledenning is indeed an important find. Is it just the actuators that are 12V only? Is the electronic control box multi-voltage, or the correct voltage?

twistedtree said:

The Gledenning is indeed an important find. Is it just the actuators that are 12V only? Is the electronic control box multi-voltage, or the correct voltage?

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You mean the levers etc. in the PH and FB? They are run off a standalone 12V battery under the PH helm.