amps for windlass control?

[Sailorman Ed]

I don't ever recall seeing this issue but how many amps ( or milliamps) are being passed in the wires going from the helm to the windlass actuator? Not the windlass motor, just the relay? I suspect it is quite small. I need to run new wires and want to size it correctly.

[nigel1]

Don't know the exact load on those wires, but the installation manual for my Muir Windlass states to use a 3 amp fuse on the positive (common) wire between the relay and the controller.

[Jammer]

Typically you'll see an inrush current of 20 amps or more and a holding current of less than 1 amp.


I would use 16 gauge

[motion30]

I do not know the amps either but they are very small wires it can't be more than an amp or two

[coopec43]

Originally Posted by Sailorman Ed

I don't ever recall seeing this issue but how many amps ( or milliamps) are being passed in the wires going from the helm to the windlass actuator? Not the windlass motor, just the relay? I suspect it is quite small. I need to run new wires and want to size it correctly.

I agree they are quite light wires but isn't it in the manual?

My winch is a Muir VRC1250. I just googled "muir winch 1250 kg manual" and it came up with the online manual. Surely it would be covered there?

https://muir.com.au/wp-content/uploa...ual_2016-1.pdf

[Sailorman Ed]

Thanks everyone. I didn't get the windlass new so no manual but I didn't think to look online so thank you Coopec43 for suggesting.



Every wire chart I can find starts at 5 amps and a min wire size of 18. These were clearly done before LED lights became common. Is there a more up to date wire size chart somewhere?
Ed

[rslifkin]

Don't go smaller than 18 AWG for the wires. ABYC specs a minimum size of 16 AWG if the wires are individual, 18 if they're sheathed (like duplex cable).

I'm pretty sure the fuse on my windlass control circuit (factory wires for it are 16 AWG) is 5 amps. That's done just fine powering the windlass solenoid, the relay for the washdown pump (activates when the windlass control power is switched on) and the receiver for the wireless remote for the windlass.

[Jammer]

Originally Posted by Sailorman Ed

Thanks everyone. I didn't get the windlass new so no manual but I didn't think to look online so thank you Coopec43 for suggesting.

Every wire chart I can find starts at 5 amps and a min wire size of 18. These were clearly done before LED lights became common. Is there a more up to date wire size chart somewhere?
Ed

Appropriate wire sizes vary by application. Wire smaller than 18 AWG is not recommended for marine use for power wiring, so that's where the charts stop.


Charts for more general applications are available that cover a wider range of sizes, see for example this chart which goes down to 40 AWG:


https://www.remingtonindustries.com/...y%20Charts.pdf


The main reasons wire smaller than 18 AWG is not recommended for marine use are that:

• Smaller wire is physically weak and more easily damaged
• Screw terminals and customary crimp splices are less reliable in these size ranges
• Voltage drop, not ampacity, becomes the limiting concern

While smaller wires are used for signal wiring, these concerns are mitigated by use of appropriate, factory-terminated connectors, a cable design that uses the cable sheath to provide a good deal of overall strength, and low currents.


Ampacity for a given cable construction is a function of resistance and heat dissipation ability. For continuously operating high-amperage circuits doubling the cross-sectional area does not double the ampacity because I2R losses still double and the heat dissipation ability at best goes up with the surface area of the outside of the insulation which is going to go up maybe 30% with the doubling of the conductor area. As a result, in higher amp circuits, there's usually plenty of conductor area to keep voltage losses acceptable,


At smaller sizes of wire it's the other way around and it becomes more common, especially in longer 12 volt circuits, to have unacceptable voltage drop even though the ampacity listed on the chart is much larger than the connected load.

[coopec43]

Originally Posted by Sailorman Ed

Thanks everyone. I didn't get the windlass new so no manual but I didn't think to look online so thank you Coopec43 for suggesting.



Every wire chart I can find starts at 5 amps and a min wire size of 18. These were clearly done before LED lights became common. Is there a more up to date wire size chart somewhere?
Ed

I always look for manuals on the internet. I download them and put them in my "Manual" folder.