Wiring Question - Windlass (non SeaRay)

Discussion in 'Electrical Stuff' started by jgoedd99, Jan 20, 2023.

  1. jgoedd99

    jgoedd99 Active Member

    191
    Aug 10, 2008
    Buffalo, NY
    1998 370 DA
    7.4 Mag MPI Horizon Inboards
    I am helping a friend do some winter work on his boat a 38' Jefferson Yachts with a Simpson Lawrence Sprint 1000 (since acquired by Lewmar) anchor windlass. The windlass manual says the working load is 60 amps and manual recommends 1 AWG or 1/0 depending on the length of the run (71' or 89' respectively). The solenoid box is in the bow of the boat and has 1/0 POS and NEG 12V wires running to it from one of the engine's battery. The run is probably closer to 60' or 70', so the wires from the battery to/from the solenoid box are more than adequate. There is a circuit breaker close to the battery on the 1/0 POS wire. I did not note the size of the breaker DUH.

    So far so good, however the power wires from the solenoid box to the windlass motor (about 7 feet long (one way)) are only 10AWG. Seems to me like the wires from the solenoid box to the windlass motor should also be 1/0 or at least big enough to carry the amp rating of the windlass circuit breaker. I was looking into replacing the wires from the windlass motor to the solenoid box with a larger wire, but i am pretty sure that the motor is supplied with permanently connected leads and are 10 AWG. So it seems like i am going to be stuck with some length of 10 AWG in the circuit. This seems like a bad situation if i cannot upsize the wires all the way to the windlass motor. Any suggestions? Thank You.
     
  2. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Given that that's how Simpson supplied it and it's been that way for X number of years, I think it's a pretty safe bet that everything is OK. It's a very short run from the motor to the solenoid box. As you noted, the length of the run is a key factor.

    If it's been like that for who knows how long... what is the reason for questioning it?
     
  3. Thornton69

    Thornton69 Well-Known Member

    Sep 15, 2014
    Northern BC
    1981 245 SDC
    2021 Solar 420
    '97 5.7 Bravo 2
    '20 Merc 25 EFI Jet
    As Dennis says, I would not worry about it.
    The reason for a larger conductor over a greater distance is to reduce voltage drop. (Current will be consistent throughout the circuit) Smaller conductors have higher resistance which will allow the voltage to drop over long distances.
    They are basically keeping available voltage at the solenoid box as high as possible.
     
  4. jgoedd99

    jgoedd99 Active Member

    191
    Aug 10, 2008
    Buffalo, NY
    1998 370 DA
    7.4 Mag MPI Horizon Inboards
    It has been like this for a while, but is not original. There are a POS and NEG 2 guage wires near the windlass that were cut and are still in the anchor locker. I have been helping him clean up a lot of "messes" left by POs. After i discovered the cut 2 guage wires in the anchor locker, I then saw the 10 guage wire running to the windlass from the solenoid. Put a clamp on ammeter an one of the 10 guage wires and measured 40 amps while running the windlass chain in and out (not pulling an anchor up). I am concerned with that amp draw on a 10 guage wire and only protected by a higher rated circuit breaker. I was thinking putting a fuse on the solenoid output that is rated more in-line with the ampacity of a 10 guage wire?
     
  5. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Forget about what was there before and focus on what is there now. 40a through a 10g wire is fine - depending on the run as noted above. It was a different windlass and a different setup.

    Put your hand on the wires while pulling the anchor in. If it doesn't get abnormally hot it's fine. Plus, like you said, the wires are "built in" to the windlass so that means it came from Simpson that way and, again, for the short run, it's fine.
     
    Halfhitch likes this.
  6. hughespat57

    hughespat57 Well-Known Member

    Sep 25, 2016
    Rock Hill, SC
    300 Sundancer 1994, trailered tri-axle LoadRite roller
    Mercruiser 5.7 260HP Alpha One Gen II, twin
    Have to disagree with keeping it

    7ft is a 14ft total run
    Per ABYC using the BlueSeas wire calculator you need 6AWG wire

    10AWG meets ampacity but fails voltage drop.

    The windless would have reduced lifting capacity due to voltage drop.

    Also you need to check the breaker rating 60A would be ok but could be it might be higher. Breakers protect wires. The 10AWG could overheat before the breaker trips.
     
  7. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Pat, did you calculate using a 3% drop? I was thinking 10% as it's not voltage sensitive like electronics.

    That said, it certainly can NEVER hurt to go bigger on wiring!
     
  8. hughespat57

    hughespat57 Well-Known Member

    Sep 25, 2016
    Rock Hill, SC
    300 Sundancer 1994, trailered tri-axle LoadRite roller
    Mercruiser 5.7 260HP Alpha One Gen II, twin
    I did use the default 3% so technically at 10% 10AWG would be acceptable.
    However I would really want to know the breaker size. If over 60A breaker 10AWG may not be acceptable.
    69A is the "recommended" protection, maximum is 80A.

    The manual for this Simpson is odd, it states a 400W motor, then 60A at working load of 165lb.
    But 60 amp would be 720W. No recommended breaker size listed. The wire size recommendation is for all segments added together which would be typical, why would one suddenly drop the size for the last segment.

    But it was mentioned the 10AWG wires come out of the motor and that is what the parts sheet shows. So maybe that is OEM.

    I went thru this exercise last year on my boat.
    Lewmar Progress 1 that I picked up and rebuilt. 1000W motor, 100A breaker recommended by Lewmar, 45ft total run motor to main buss bars. 10% would allow 4AWG, I used 2AWG (5%). I admit I tend to be conservative when working over about 15A.
     
  9. jgoedd99

    jgoedd99 Active Member

    191
    Aug 10, 2008
    Buffalo, NY
    1998 370 DA
    7.4 Mag MPI Horizon Inboards
    I am following your discussion as it is all the issues i have been going through in my head. Going to boat today to do a few other things and am going to check breaker size and try again to get at the motor to see if there are terminals or hard wired (there is a rubber boot over the motor that will not let me see the wire connections at the motor). Manual says take a heat gun to it and it will become flexible allowing removal.

    The breaker size is the biggest issue in my mind, if it's a 100 amp breaker that 10 gauge wire could be an issue. I also was thinking at least a 6 gauge wire from the solenoid to teh windlass motor based on ampacity and voltage drop. If there are terminals on the motor and i can access without removing winch (winch is not budging)) i will upsize to a 6 gauge. If it is hard wired to the motor with no terminals and the breaker is greater than 60 amp, i may put a fuse coming off the solenoid box sized for 60 Amp. Will report back. Thanks for great responses.
     
  10. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Hmmm. I agree - that is strange. Math is math is math... until now

    You're more well versed in this stuff than I am, but I suppose it's because Simpson would have no idea where the solenoid is located so it's better to just make a general recommendation and... does the solenoid essentially count as a "new" power source? Meaning, if the actual battery was only 7 feet away, then all that would be needed is the 10g? The need for the larger gauge is simply because of the run from the battery to the solenoid.
    [/QUOTE]
     
  11. Bill Curtis

    Bill Curtis Well-Known Member

    533
    Mar 24, 2022
    Ahoskie, NC
    '95 220 Overnighter
    454 Mag Bravo3
    In my humble opinion: I would suggest that the run between battery and sol and the run between the sol and windless would be additive. IOW overall run, even with solenoid, between battery and windless should count as one in the same for the calculations of size wire between battery supply and battery load. Voltage drop calculations should indicate if wiring is of sufficient size.

    Of course, voltage drop across the solenoid should be benchmarked and included in the overall voltage drop.

    Connect meter B+ to battery + and meter B- to load terminal to measure overall voltage drop and go from there. Then do same for negative / return circuit. The lower the voltage drop, the better, as voltage drop indicated circuit resistance under load.
     
  12. hughespat57

    hughespat57 Well-Known Member

    Sep 25, 2016
    Rock Hill, SC
    300 Sundancer 1994, trailered tri-axle LoadRite roller
    Mercruiser 5.7 260HP Alpha One Gen II, twin
    Since downloading the Simpson manual I think the limitation is the motor they selected. Having no external terminals it was likely delivered with a fixed length of 10AWG, say maybe 10ft. And the installer was expected to place the solenoid 10ft or less from the motor. So technically as long as the breaker is sized for the smallest wire in the circuit then all is ok.

    Its just a little unusual that's all, we are most likely just over thinking the whole thing.

    Now IF someone sized breaker based on the larger wire, then either reduce it to something less than 60A max would be my recommendation. Breakers will carry 100% load indefinitely, they operate on a trip curve, 110% could be 5 minutes, 150% might be a minute, a dead short would spike to what the conductor resistance will allow and the breaker would trip instantly.
    https://www.bluesea.com/products/7184/285-Series_Circuit_Breaker_-_Surface_Mount_60A
    This curve is 20-30 seconds at 150%, that's good to prevent inrush (motor start up) current from nuisance trips.

    If the breaker is say 100A the other option is along what you mentioned and that goes in line with @Lazy Daze. If we consider the change in wire size as a new power "source" point and fuse appropriately. On the solenoid positive input terminal you could add a 60A MBRF. But this introduces a safety device in a location that could be hard to replace, changing the breaker is more convenient.

    https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A
     
  13. jgoedd99

    jgoedd99 Active Member

    191
    Aug 10, 2008
    Buffalo, NY
    1998 370 DA
    7.4 Mag MPI Horizon Inboards
    The breaker at the helm station is 70 Amps. I got the rubber boot off the motor and confirmed the motor is hard wired, and as HughesPat suggested was supplied with a fixed length of 10 GA wire (about 30"), and then someone spliced in an additional ~ 4' of 10 GA to get to the solenoid.

    I think the expectation is that the solenoid box would be in close proximity to the windlass (as SeaRay does). However as we SeaRay owners know, getting to that relay box in the anchor locker is NOT fun. So the placement of the solenoid under the forward berth is more convenient but creates this issue. NOTE - I think someone relocated it at some point as i mentioned there are 2 large gauge "cut" wires that terminate in the anchor locker.

    At this point there is a 70 Amp breaker protecting a 7 foot length (14' round trip) of 10 Guage wire. The issue is not voltage drop, it is current flow. I appreciate all your expertise, and strictly from a regulation/standards (ISO/ABYC...) standpoint should i leave it or put an overcurrent device prior to the 10 guage wire? And if an overcurrent device is warranted, should it be an MRBF ($$$) or would a Maxi (ATO) fuse suffice ($). You can get MAXI fuses with 8 AWG leads.

    Thanks again.
     

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