Bow Thruster/Winch

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MD106

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Hi Everyone,
S41 is now in the water in Canada. All is well save the bow thruster and winch not responding.
I've checked fuses, replaced on suspect battery cable and a circuit breaker.
I have a group 27 battery deep cycle/starting.
It has 12.55v at battery, 9v at the circuit switch and 4.2v at the motor/solenoid in resting state.

Anythoughts on where to go next.
TIA
I
 
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I note your thread - seems unusual you have had no reply

I'm simply re-freshing it to keep it active and I am sure someone will comment

But given that both items are not working it certainly looks like a 'common' electrical issue.

I might question the voltages you are quoting - seems a significant drop.

If you have a small starter battery, ie you can carry it, I might disconnect it and take to the bow and connect to each item with a short, heavy duty, cable run and try it to each in turn

Jonathan
 
Thinking a bit further

I don't have a bow thruster (2 engines instead :) ) but my assumption would be that you do not use a bow thruster without running the engine. Similarly you might, as we do, run the windlass with the engine running at low revs and usually out of gear. We run the engine when using the windlass as we are not purists and having the engine running allows power setting and a controlled exit from an anchorage etc etc.

Try running the engine - whose alternator will perk up the battery voltage, measure the various voltages and try windlass and separately bow thruster. You can do this instead of my original idea of carting around a 12 v battery (large enough to use as an engine start). Running your engine should give you much higher voltage at the battery and at either, or both, motors

Another check is the integrity of the connections - are the nuts, thread terminals, on the power cables - motor/solenoid clean and tight. The equipment you are 'questioning' are in the worst location for electrical components and the connections might benefit from some aggressive use of a wire brush.

Jonathan
 
Neeves said:
I note your thread - seems unusual you have had no reply

I'm simply re-freshing it to keep it active and I am sure someone will comment

But given that both items are not working it certainly looks like a 'common' electrical issue.

I might question the voltages you are quoting - seems a significant drop.

If you have a small starter battery, ie you can carry it, I might disconnect it and take to the bow and connect to each item with a short, heavy duty, cable run and try it to each in turn

Jonathan
Click to expand...

Thanks Jonathan, I appreciate the assistance!
Mitch
 
Agree with Neeves.

Our 30' has the batteries at the stern and was built with very heavy wires going to the thruster directly, operation managed via relay as not to feed the big load over a switch. Very standard setup (Side-Power brand).

However, when using the thruster at idle it would use so much power that other devices on board cut off, then restarted when the thruster joystick was released. Annoying and not good for anything, so I added a dedicated, common 72 aH Silver Cadmium start battery, in parallel near the thruster, kept the heavy wires in place for charging, and added a heavy relay to cut the original connection the split second I touch the joystick. Hence, the thruster draws from the added battery only, when working and returns to receive charge when not.
Took a start battery because the use of a thruster is pretty similar to a starter: Short draws of high power, then left alone to recover.
 
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ChromeDome said:
Agree with Neeves.

Our 30' has the batteries at the stern and was built with very heavy wires going to the thruster directly, operation managed via relay as not to feed the big load over a switch. Very standard setup (Side-Power brand).

However, when using the thruster at idle it would use so much power that other devices on board cut off, then restarted when the thruster joystick was released. Annoying and not good for anything, so I added a dedicated, common 72 aH Silver Cadmium start battery, in parallel near the thruster, kept the heavy wires in place for charging, and added a heavy relay to cut the original connection the split second I touch the joystick. Hence, the thruster draws from the added battery only, when working and returns to receive charge when not.
Took a start battery because the use of a thruster is pretty similar to a starter: Short draws of high power, then left alone to recover.
Click to expand...
Thats good thinking there, and if you use your thruster a fair bit, I can see the value of it. The OPs problem needs solving before he tries that route if he needs to though. My feeling is it's pretty simple to say, and on a boat, quite hard to do, potentially. The cable needs checking all the way. It’s either got some very poor connections ( most likely) or its worn though somewhere, and only just making a connection (hopefully not). Static voltages so low indicate a distinct lack of vaseline on the connections in the past. Sure, the battery voltage is a tad low at the terminals, but on the end of a 30 odd foot cable, probably 6mm sq or more, for a windlass or thruster, you should still have at least 98% of that when not under load. Connections, get them cleaned up then protected.
 
I'm not an electro magician - but we don't know how big the cables are. Proving I'm not an electro magician - what is a a circuit switch or is that the same as a circuit breaker? I don't understand why there is a switch and breaker. I also don't understand why there are fuses (plural) - unless they are in the control circuits. But with 2, what I might call switches, a split in the feed, and more than one fuse, plus connections to the solenoid - there are an awful lot of joins
.
My understanding is there is one circuit breaker, presumably somewhere aft, and that both devices draw from one cable feed. I come to this simple conclusion as neither device works. This leads to unnecessary cable connections - but maybe this is common (to have a single cable feed for both bow thruster and windlass).

MD106 said:
Thanks Jonathan, I appreciate the assistance!
Mitch
Click to expand...

No problems Mitch - its a forum we are here - to help each other.

And - welcome to the forum.

I'm not a sparky - and not ashamed to admit to my lack of knowledge. But you are not alone with the issues you describe - been somewhere similar - I'm sympathetic.

Hopefully we will come up with some answers.

Jonathan
 
Should be ok,thruster and winch off same cable, but not at same time.

Fyi. I have 30 footer 250 amp rated thruster run from start battery. Fused at battery. 70mm cables.

I can't see problem with adding winch by adding positive and negative studs in bow. Hopefully winch not rated higher than 250amp so no need for another fuse.

Hope that is of interest.

I am not a spark.
 
All the cable and connections need a good inspection. Standing voltage of 4 volts at the end with no load means a problem somewhere.
Was this all working last year or is it a new / modified installation ?
 
IanCC said:
Should be ok,thruster and winch off same cable, but not at same time.

Fyi. I have 30 footer 250 amp rated thruster run from start battery. Fused at battery. 70mm cables.

I can't see problem with adding winch by adding positive and negative studs in bow. Hopefully winch not rated higher than 250amp so no need for another fuse.

Hope that is of interest.

I am not a spark.
Click to expand...
I did the same but added a 50 amp circuit breaker for the windlass to protect its wiring as the BT fuse is 250 amp slow type.
 
That's an enormous voltage drop from battery to motor/solenoid at rest. There are much better electricians on here than me, but I agree with the contributors so far. Either something has happened to the circuit between these two points, or the battery is hardly able to deliver any current as it fails. Does that battery run anything else? If so, does it work? Did this circuit work previously or is it newly commissioned? Neeve's suggestion of checking the thruster and winch with a different battery will confirm that they are OK. A diagram might help too.
In case it helps, we have aft batteries running a forward bowthruster over a cable run of 8m each way. The cable is 135mm sq to handle the current without too much loss of power over that length. Boat only 35ft
Good luck
 
The voltage drop isn't because the battery is dodgy, it’s because the wiring is dodgy. 95% certain its corroded connections, bad enough to be obvious on inspection. At the battery, at the relays, or at the windlass or thruster.
 
MD106 said:
Hi Everyone,
S41 is now in the water in Canada. All is well save the bow thruster and winch not responding.
I've checked fuses, replaced on suspect battery cable and a circuit breaker.
I have a group 27 battery deep cycle/starting.
It has 12.55v at battery, 9v at the circuit switch and 4.2v at the motor/solenoid in resting state.

Anythoughts on where to go next.
TIA
I
Click to expand...
Hi Everyone

Thanks for the helpful troubleshooting tips. They all helped to diagnose the issue.
Solution:
Replaced one 2 gauge wire within the circuit as it was quite blackened at the connector, replaced the switch, replaced the 12v lead from the controller to the solenoid.
After that it made that great sound of a propeller spinning in the water!

Happy to have a 2 digit repair for once!

Thanks again,
Mitch
 
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