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Alternator size vs Windlass current
I am still trying to decide on a windlass for our boat. Perhaps some the
experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) Some suitable horizontal windlasses for a 32 ft boat draw as much as 90A (e.g. Quick Eagle 500/700) If we have the engine running at say 1500rpm while pulling up the anchor, we may be putting about 35A into the 200AH house bank, if we are lucky. At the same time, the windlass is drawing up to 90A and other items like the refrig unit are still drawing current. We could have a shortfall of 60A for 5-10 minutes. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? GBM (PS: I have 6 Ga wiring already installed, but will change if need be) |
Alternator size vs Windlass current
They will not draw full amperage if used properly. use your engine NOT
your windlass to move the boat over the anchor. The most stress your windlass should ever have is lifting the anchor, chain and rode. it should not be used to free an anchor (Except min mud etc) I have the Lofrans 1000 Watt (1000/12 = 83 Amps... 2 group 31s in parr can handle that + 50 amp DC charger + alternator) (Marlin maybe... not sure of the model). I only have an issue if I disobey my own rule... Size the windlass to about 2x the weight of the anchor, chain and rode and you should be fine. mine is supposed to be for a boat up to 40' and I have run a 48' 50K LB boat with it for 5 years including LOTS of diving on 130' deep spots (300'Rode, 40' BBB chain, Steel danforth) BTW... I love the combo lofrans.... chain/rode gypsy + a capstan you can disconnect and use for the second anchor or dock lines. GBM wrote: I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) Some suitable horizontal windlasses for a 32 ft boat draw as much as 90A (e.g. Quick Eagle 500/700) If we have the engine running at say 1500rpm while pulling up the anchor, we may be putting about 35A into the 200AH house bank, if we are lucky. At the same time, the windlass is drawing up to 90A and other items like the refrig unit are still drawing current. We could have a shortfall of 60A for 5-10 minutes. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? GBM (PS: I have 6 Ga wiring already installed, but will change if need be) |
Alternator size vs Windlass current
GBM wrote:
I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) Some suitable horizontal windlasses for a 32 ft boat draw as much as 90A (e.g. Quick Eagle 500/700) If we have the engine running at say 1500rpm while pulling up the anchor, we may be putting about 35A into the 200AH house bank, if we are lucky. At the same time, the windlass is drawing up to 90A and other items like the refrig unit are still drawing current. We could have a shortfall of 60A for 5-10 minutes. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? NO. This is one time when more is better (PS: I have 6 Ga wiring already installed, but will change if need be) Save the #6AWG for something else. #2AWG is cutting it close. I'd probably use 1/0. Add as much house battery capacity as you can afford and can find space to keep it. Personally, I don't like adding battery capacity in the bow near the windlass. Lew |
Alternator size vs Windlass current
In article ,
"GBM" wrote: If we have the engine running at say 1500rpm while pulling up the anchor, we may be putting about 35A into the 200AH house bank, if we are lucky. At the same time, the windlass is drawing up to 90A and other items like the refrig unit are still drawing current. We could have a shortfall of 60A for 5-10 minutes. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? Go with the larger one as the momentary *maximum* draw will be absorbed by the batteries, and replaced soon after. Truth be told, if you don't have an auxiliary battery real close to the windlass, you lose a lot in long cables. A battery fed by smallish cables from the charger(s) may weigh and cost less than proper cables the whole distance. You'll minimize required draw by using the windlass properly: solely to raise the rode and anchor, letting the prop move the boat forward. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
Alternator size vs Windlass current
Would you really use the windlass for 5-10 minutes? Probably more
like 2 minutes usually. And the current won't be 90 Amps just lifting the anchor (unless its huge and you're in 500 feet of water), the max draw would only be if you straining, something that almost always unnecessary. In wind you should drive the boat up over the anchor, but in light air you can pull the chain tight, then let the weight of the chain pull the boat up - repeat a few time until you're over the hook and wait for the bobbing of the boat to work it loose. The net result may be more charge in the bank than when you started And the shortfall isn't really that bad, since running the engine for a few more minutes is going to recover it. This is what batteries are for. You're talking about 10 Amp-hours even in your worst case reckoning. If you have a large DC fridge, you could consider turning it off - we do that on occasion if we need to run the engine at top RPM to make a bridge opening, etc. But more often than not, I've set my regulator down to 30 amps if I'm expecting to use the engine long enough to charge the bank. I wouldn't worry about this at all. As for the wire, the WM catalog has the chart - that should tell you if the size is right, but it seems a bit small. Some people add an extra battery at the windlass that can be charged with low current, but that seems complicated. If you want to add, enlarge your house bank - that's always a good thing. GBM wrote: I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) Some suitable horizontal windlasses for a 32 ft boat draw as much as 90A (e.g. Quick Eagle 500/700) If we have the engine running at say 1500rpm while pulling up the anchor, we may be putting about 35A into the 200AH house bank, if we are lucky. At the same time, the windlass is drawing up to 90A and other items like the refrig unit are still drawing current. We could have a shortfall of 60A for 5-10 minutes. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? GBM (PS: I have 6 Ga wiring already installed, but will change if need be) |
Alternator size vs Windlass current
The windlass runs off the battery, not the alternator. Any winch worth
its salt will draw far more current than the alternator can replace in real time. Having well (over) sized cables (up and back) to the winch will give better results but this can be expensive. Sometimes it is cheaper and more effective to put a dedicated battery at the winch with a light gauge charging line to replenish the battery. See the article at http://www.yandina.com/Bank3.htm |
Alternator size vs Windlass current
GBM wrote:
I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. As others have pointed out, this shouldn't matter. The windlass' power comes from the battery bank, and the draw is only going to be 2 minutes or less anyway. Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? No! You want a windlass of a size to be of practical use... which means a windlass that will move heavy objects you can't move with your back muscles. (PS: I have 6 Ga wiring already installed, but will change if need be) For a windlass? Not big enough by at least a couple of sizes, unless your battery is less than 1' away from the windlass terminals (which would make a cable run of 2' remember). The issue of whether to add a battery up forward for the windlass is one that can only be decided by an individual, based on his preferences. Heavy cable is expensive, it may be cheaper to put a battery up front; but then the battery will need charging & maintenance, and adds to weight up forward where you don't want it for sailing. Fresh Breezes- Doug King |
Alternator size vs Windlass current
Heavy duty tinned cable is not all that expensive. I bought sixty feet (30'
out, 30' back) of 1/0 tinned cable from Cobra for about $2 a foot. I did not have to buy another battery to install in the bow and add even more weight up forward along with the windlass, anchor and 150' of chain. The cables distribute their weight along the length of their run to an already installed battery. A 100 amp breaker within a foot of the battery ensures we don't have live cables running all over the boat. And it is the battery, not the alternator, that drives the windlass. As it happens, we have a high output charging system but that only means you put the juice back in the battery faster, not raise the anchor faster. As others have mentioned, use the engine to pull the boat over the anchor and break it out, not the windlass to lift the sea floor. Don't know about others but ours is a Lewmar Concept 1 gypsy and captstan with dual station/dual direction switches. The switch wiring is abominable. It is very small guage and not tinned and handles very low current to a solenoid that does the heavy-duty switching. The low-current wiring rapidly turns to red dust and the switches regularly fail. Put in decent wiring, you say. The existing wiring is integral into the switch. All I can do is keep peeling back to bright copper and splice yet again. But I am running out of space. I'll think of something. The motor on this unit also failed. I had it rebuilt at a local automotive elctrical shop. Lewmar has been less than helpful. |
Alternator size vs Windlass current
Gogarty wrote:
Don't know about others but ours is a Lewmar Concept 1 gypsy and captstan with dual station/dual direction switches. The switch wiring is abominable. It is very small guage and not tinned and handles very low current to a solenoid that does the heavy-duty switching. The low-current wiring rapidly turns to red dust and the switches regularly fail. Put in decent wiring, you say. The existing wiring is integral into the switch. All I can do is keep peeling back to bright copper and splice yet again. But I am running out of space. I'll think of something. Sorry to hear about your experience with the Lewmar. I have a Concept (forget the #) windlass on my boat and have had good service from it for 7+ years. Lewmar foot switches on the deck forward and the supplied Lewmar 'remote' toggle switch in the cockpit. Regarding your corrosion problem: On my boat, the connections (soldered as I recall) for the deck switches are belowdecks (nominally dry) and are protected with sealant (coax seal or 3M splicing compound and heat shrink). The cockpit toggle switch is still going strong in spite of being exposed to the inside of a locker which is usually piled with damp and salty lines- corrosion heaven. Again, the connections (push-on spades) are properly protected with sealant and heat shrink. The toggle switch is a simple on-off-on momentary SPDT switch which can be replaced with an off-the-shelf unit from any good electronics supplier. As you say, it carries little current, so it's not a critical item. The rubber switch covers in the foot switches seem to be holding up, but are an obvious leak threat. So far, using tinned (marine-grade) wiring and proper sealing of inline connections seems to be doing the trick for me. Most of my belowdecks branch connections (tapping into the light circuit, etc) are made via terminal blocks, so it's easy to keep an eye on what's happening, and troubleshoot as well. I'm keeping my fingers crossed about the motor after your experience. So far, the windlass has been the only Lewmar product on the boat that hasn't turned to rubbish. Traveller and 'racing' blocks are a witches' brew of aluminum and various tiny stainless setscrews which are totally unsuited to marine use. No more Lewmar junk for me...except for that great windlass! John |
Alternator size vs Windlass current
GBM wrote: I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) I would echo the comments made by others here- get a decent sized windlass and put in heavy-duty wiring. It's expensive, but just part of the 'hidden cost' of windlass installations. I've got a Lewmar Concept windass with an 80A breaker, but I'm sure it never draws anything like that current in practice. Usual anchor is a 35#CQR with 5/16 chain for the first 175 ft, then rope. Alternator is 55A Hitachi, battery banks supply about 300Ah or so. When using the windlass, we run the engine and parallel the battery banks- probably overkill. Wiring (this is important) is 1/0 tinned marine cable with swaged-on lugs. My marine electrical advisor (Paul Thornton of Oakville, ON) insisted on this over my objections, and he was right. Boat is 30ft sloop, batteries aft. Incidentally- in calm conditions, using chain rode, there's nothing wrong with moving the boat up to the anchor by jogging the windlass and letting the weight of the chain pull the boat forward. Once the chain is close to vertical you can drive ahead with the motor to break out the anchor and hoist the anchor with the windlass. It's handy having a cockpit switch for the windlass if you are single-handing. You will love your electric windlass if you do it right- no more cranking for me (until it breaks). Cheers John |
Alternator size vs Windlass current
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Alternator size vs Windlass current
"John" wrote in message oups.com... GBM wrote: I am still trying to decide on a windlass for our boat. Perhaps some the experienced cruisers can help? Our alternator output, is nominally 55A, but likely actually quite a bit less. Max size alternator recommended for Yanmar 2QM15 engine is about 80A) I would echo the comments made by others here- get a decent sized windlass and put in heavy-duty wiring. It's expensive, but just part of the 'hidden cost' of windlass installations. I've got a Lewmar Concept windass with an 80A breaker, but I'm sure it never draws anything like that current in practice. Usual anchor is a 35#CQR with 5/16 chain for the first 175 ft, then rope. Alternator is 55A Hitachi, battery banks supply about 300Ah or so. When using the windlass, we run the engine and parallel the battery banks- probably overkill. Wiring (this is important) is 1/0 tinned marine cable with swaged-on lugs. My marine electrical advisor (Paul Thornton of Oakville, ON) insisted on this over my objections, and he was right. Boat is 30ft sloop, batteries aft. John, Your example perhaps explains the reason for my question. You are right - If I go to a windlass that draws 80 - 90A, I WOULD need large cables. Wiring size comment: I doubt windlass wiring really needs to be sized for 3% drop, but if this is desired, your wire size is probably about right. At 10% drop the wire size could be 2AWG which I would think would suffice. If the engine is running, voltage will be higher anyway, so voltage drop should not be a major issue (Out of interest, how did you conclude that your advisor was right about the 1/0 wire?) Getting back to windlass choice: Why choose a windlass that draws such a high current on a 30-32 ft boat? There are windlasses available that use epicyclic (planetary) gears that are much more efficient. For example, a Quick Genius (similar specs to Concept 1) draws just 40A at working load - Quick recommends 6AWG wire for a 50-60ft return trip. See: http://www.1stopmarineshop.com/Quick%20Windlass.html . The Lofrans Dorado has similar lower current draw. http://www.lofrans.it/english/intro.html There are vertical units that are also efficient. Is there a downside to using one of the higher efficiency units? Regarding adding to battery power: I could use a dedicated battery, but can't see the point of mounting this forward, especially with a combiner. After raising the anchor, surely the battery could be quite low and draw most or all of the alternator output. Can't see how Andina Maries' 10ga wire would handle a long run carrying say 50 -80A from the alternator unless the combiner limits the current (longer recharge time) I think one of my main concerns has been answered - If I draw 80A for 5-10 min, I will not deplete my house batteries very much and even with my low output alternator, they will recover if I run motor for a short while. If I chose a high efficiency unit that draws just 40A, I will be even better off electrically, and its seems will not have to sacrifice much in pulling power? Thanks for the input! GBM |
Alternator size vs Windlass current
"GBM" wrote in message ... Question: Would I be better to buy a somewhat undersized windlass that might only draw 35A? (e.g Lofrans Dorado with gypsy on wrong side :( ) or buy the larger unit and draw a bigger current? It would be far better to install enough battery capacity so you don't have to worry about it. But in practice even a single 100 amp hour battery will not be seriously affected by a 60 amp draw for 5-10 minutes. I would prefer to have at least 200 AHs of battery capacity however. And you really need 400 AH of capacity if you expect to anchor more than one night with lights and refrigeration going. And then you might want a larger capacity alternator with an external 3 stage regulator. You get the picture- don't worry about your windlass size, worry about your battery capacity and how you are going to recharge it. David |
Alternator size vs Windlass current
GBM wrote: John, Your example perhaps explains the reason for my question. You are right - If I go to a windlass that draws 80 - 90A, I WOULD need large cables. I'm quite sure I've never drawn close to this current with my windlass. You should understand that you will need the same number of watts of power to hoist your anchor at a given speed- no matter which windlass you choose. A larger capacity windlass 'just lazing along' will draw the same current as (probably less than) a smaller one which is near stalling. (Out of interest, how did you conclude that your advisor was right about the 1/0 wire?) A trip on another boat with undersized wiring and problems, and no problems with my installation. Positive comments on surveys. Great rep of advisor. Getting back to windlass choice: Why choose a windlass that draws such a high current on a 30-32 ft boat? There are windlasses available that use epicyclic (planetary) gears that are much more efficient. I wanted a vertical axis windlass with rope/chain gypsy and rope capstan above. There were limited choices. Current draw is not an issue. I didn't want a flimsy unit from an unknown maker. There's not a big difference in 'efficiency' between different motor designs for windlasses. Compare speed of hoist and load (in N)- you will need the same number of watts with any unit. There's no 'free lunch'. You are trading speed of hoist, force and power consumption. For example, a Quick Genius (similar specs to Concept 1) draws just 40A at working load - Quick recommends 6AWG wire for a 50-60ft return trip. See: http://www.1stopmarineshop.com/Quick%20Windlass.html . The Lofrans Dorado has similar lower current draw. http://www.lofrans.it/english/intro.html There are vertical units that are also efficient. Is there a downside to using one of the higher efficiency units? I think one of my main concerns has been answered - If I draw 80A for 5-10 min, Well, one of the 'high efficiency' units may take 5-10 min to hoist the anchor and rode, but I've never needed more than a couple of minutes to pull in even 300 ft of rode and anchor. A couple of ammeters in your system will open your eyes to the actual situation- put one in the charging line and another on the load side. You will be amazed how little current is produced by your alternator (without an external over-ride regulator). A couple of reading lights left on for the evening will pull more energy from your battery bank than hoisting your anchor with your new windlass. So many choices, so little cash! Cheers John |
Alternator size vs Windlass current
On Wed, 19 Jul 2006 18:41:24 -0700, "David&Joan"
wrote: don't worry about your windlass size, worry about your battery capacity and how you are going to recharge it. Exactly, get the right windlass for the job. |
Alternator size vs Windlass current
"John" wrote Well, one of the 'high efficiency' units may take 5-10 min to hoist the anchor and rode, but I've never needed more than a couple of minutes to pull in even 300 ft of rode and anchor. John - If you compare specs and read the tests/reviews, you will find that some windlasses do consume less power for the same working load and speed. Here is some data from the manufacturer's literature comparing the Lewmar Concept 1 with a Quick Genius 600 (admittedly quite different windlasses): Working load:- Quick: 85Kg Lewmar 45Kg (seems low?) Maximum pull:- Quick:680Kg Lewmar 650Kg Speed at working load:- Quick: 44ft/min @ 85kg Lewmar: 46ft/min @ 45kg Current draw at working load: Quick: 40A Lewmar: 80A This is not a Lewmar vs Quick thing. Even within the same company, there are efficiency differences. I have looked at many windlasses that would suit my boat (using 3X ground tackle weight) and found large discepancies in power and current usage. The Quick reps confirmed this and explained that it was due to lower losses in the gearing of some newer designs - Power required can be 30-50% less for the same load, even if speed is comparable. Everyone has their own take on these things, but mine is to put in the most efficient unit that will do the job. This is partly driven by limited engine HP which limits alternator size, which limits battery bank capacity. It is also driven by keeping weight and dollars invested to a minimum ;) GBM A couple of ammeters in your system will open your eyes to the actual situation- put one in the charging line and another on the load side. You will be amazed how little current is produced by your alternator (without an external over-ride regulator). A couple of reading lights left on for the evening will pull more energy from your battery bank than hoisting your anchor with your new windlass. So many choices, so little cash! Cheers John |
Alternator size vs Windlass current
"Wayne.B" wrote Exactly, get the right windlass for the job. That is the object of this discussion! Question is, is why do some windlasses draw double the current when everything else (max load, working load, chain speed) is the same or even sometimes worse? GBM |
Alternator size vs Windlass current
On Thu, 20 Jul 2006 11:47:29 -0400, "GBM"
wrote: Question is, is why do some windlasses draw double the current when everything else (max load, working load, chain speed) is the same or even sometimes worse? Higher current draw is almost always indicative of a more powerful motor. Max load, working load and chainspeed are all fuctions of how strongly the unit is built and the gear ratios. Weight and size are good indicators of overall ruggedness as well. A small light weight unit with similar specs is frequently compromised in the area of durability. My former boat had a beautifully designed windlass which was very sleek looking and not terribly large for its power and speed. The gear box however looked like a Swiss watch on the inside and was just about as reliable when exposed to a rough and tumble, salt water environment. |
Alternator size vs Windlass current
"GBM" wrote:
Question is, is why do some windlasses draw double the current when everything else (max load, working load, chain speed) is the same or even sometimes worse? snip Use LightHouse, manufactured about 30 miles from here, as the gold standard for this size windlass. Lew |
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