Its been a long project, and still on going, but I'm happy with it so far!

[chowdan]

Originally Posted by stormalong

I wouldn't run a windlass load through the same wire as the main panel. I would run it directly from the fuse on the battery to it's own circuit breaker and then directly forward. There are side effects to a high load draw on the same wire as all of your other circuits. Operating the windlass may cause a voltage sag on that shared wire and affect your electronics.

I would disagree with that statement, but I also think it is purely dependent on how one designs the system and is used at the intended way. I dont expect to be weighing anchor without the engine running as this will be the "primary" source of energy to all loads(including windlass). If my engine isn't running, then sure I can see voltage sag will cause problems with electronics. Regardless of where I take my power from, directly from the battery or a switched distribution bar, voltage sag will occur, its a matter of where you place that sag. To solve the problem of that, one just needs to increase the wire size to the distribution bar.

That said, how often does one's windlass max out or trip a breaker? My breaker is a 125amp breaker, with a 1200w motor. At 50 foot run(round trip), i will see a roughly 5% voltage drop at the windlass. I'm no math genius, so maybe someone can help this out, but here it goes:

Load at max usage:
Load @ max: 110amps(100 for windlass 10 for "house loads"
battery internal resistance: 3.8mΩ
Voltage(alternator running): 14.25v

110 * 0.038 = 3.99v
14.25 - 4.18 = 10.07v

So 10.26v would be what we expect to "see" when running windlass all out + everything else being pulled online.

Load under average usage - number is unsure as windlass has yet to be used
Load @ 1/2 = 60amps(50 for windlasss, 10 for house)
battery internal resistance: 3.8mΩ
Voltage(alternator running): 14.25v

60* 0.038 = 2.28v

14.25 - 2.28 = 11.97v

Supposedly my plotter power inputs are "8v to 16v" but I know that running lower definitely will affect it and the rest of the system.


Also, stormalong, please dont take offense to my blob of text above, this is more of me just working out the math for my brain to fully understand what I've done and give some reasoning behind the system design. I ran the numbers previously, but definitely didn't run them in too much detail, was more of just a mental calculation. I fully accept that if i read this tomorrow, it may sound quite offensive, so I do apologize in advance for that.

[stormalong]

I am not offended. I think my suggestion creates a more robust electrical system.

I plan for worst case possibilities. I always design my systems to be independent rather than interdependent.

I am sure you will be fine.

[CharlieJ]

@chowdan/stormalong
You have covered voltage sag but, in my view, the more insidious problem is the high voltage spike that can be produced when a high current drawing piece of rotating equipment, like a windlass or bow thruster, stops. That spike will return to the source, the battery, where it will be quenched. If the circuit back to the battery includes the panelboard, then the entire DC system can experience very, very high instantaneous voltage.

To mitigate this, I wire the high draw equipment to the B+ and B- busses closest to the battery and power the equipment's control circuit; e.g., windlass foot switches and bow thruster joy sticks, directly to the main panel board.

[SeaBreeze-1]

First off, nicely done. I've been through this exercise myself and found out afterward that it will give you great confidence in being able to diagnose and handle just about any electrical problem that might arise when you least expect it.

Like most people looking at your pictures, I found that the color coding of the cables makes for a certain amount of confusion and really should be corrected to help to negate any confusion.

I did notice that the black cable, feeding from the switch to the buss bar is mounted "upside down", based on how the lug is fastened to the buss bar (notice the angular space between the lug and buss bar plate). This is a poor connection that comes loose easily, can dramatically reduces power flow and potentially cause a very hot spot/fire in the circuit. You need to turn or replace the lug and remove some of the shrink tubing so that it fit flat against the plate. You may want to check all the other lugs to ensure that they are oriented properly. It's a common problem but is easily caught and fixed.

ABYC standards recommend that all positive-feed buss bars should have a protective cover over them to eliminate the possibility of accidental shorts. Blue Seas makes some covers for their bars or, if you're a little inventive, you can fabricate your own from non-conductive material that's up to the job. Negative bars don't require covers.