Can an alternator be to big?
I have been offered a really good deal on a high amp (325 amp) fire engine
alternator by the city vehicle maintenance shop. It was purchased as a test unit but due to some budget cutbacks ended up being to expensive to equip the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and 275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp Leece Neville as a spare. My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk charge. Is my Xantrex smart regulator going to keep this monster from cooking my battery bank? -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
Glenn Ashmore wrote:
I have been offered a really good deal on a high amp (325 amp) fire engine alternator by the city vehicle maintenance shop. It was purchased as a test unit but due to some budget cutbacks ended up being to expensive to equip the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and 275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp Leece Neville as a spare. My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk charge. Is my Xantrex smart regulator going to keep this monster from cooking my battery bank? A smart regulator should have no problem at all with an over-size alternator. In the end, the battery itself will determine the rate at which it will accept charge. With so large a bank and so ample an alternator, a soft-start feature on the regulator will add life to your belt(s). And belts and slippage may also limit charging current. Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Can an alternator be to big?
Keep in mind that it'll probably take at least dual belts if not
toothed ones and suck up some horsepower from the engine. If it's charging a lot while you go to idle, it could kill your engine. That all being said, still sounds like a deal. Just have to get the right control circuitry. chuck wrote: Glenn Ashmore wrote: I have been offered a really good deal on a high amp (325 amp) fire engine alternator by the city vehicle maintenance shop. |
Can an alternator be to big?
Don't think there will be a problem there. The alternator mount is already
set up for dual BX cogged belts which should be able to handle 12HP. I did that because I didn't want that Leese Neville squealing. Because this thing puts out a lot more amps at lower RPM than the LN I think I will increase the pulley diameter which should increase the power handling capacity even more. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "Keith" wrote in message oups.com... Keep in mind that it'll probably take at least dual belts if not toothed ones and suck up some horsepower from the engine. If it's charging a lot while you go to idle, it could kill your engine. That all being said, still sounds like a deal. Just have to get the right control circuitry. chuck wrote: Glenn Ashmore wrote: I have been offered a really good deal on a high amp (325 amp) fire engine alternator by the city vehicle maintenance shop. |
Can an alternator be to big?
I hope you were increasing both pulleys so the alternator RPM was the
same? If the alternator sucks up too many horsepower, especially when docking or emergencies, a field disconnect switch can be added to remove the load temporarily. |
Can an alternator be to big?
chuck wrote in news:1152835959_12681
@sp6iad.superfeed.net: And belts and slippage may also limit charging current. May? .. .. .. .. .. WILL! 325A x 14V = 4550 watts divided by 746W/hp = 6.1 HP plus the conversion losses, probably over 10HP. How big was that Yanmar 2GM in that boat??....(c; How many HP is a V-belt capable of delivering at 2000 RPM, anyways? How many pulley Vs does the alternator's pulley have, if it has pulleys at all? Two fan belts are NOT going to pull a 200 or 325A alternator for long..... It's hard enough to keep a 120A fan belt from squealing.... |
Can an alternator be to big?
Actually reducing the alternator RPM is the idea. This thing puts out
200Amps at an alternator speed under 2000 RPM. With the pulleys I have now that is an engine speed of about 800 RPM. I need to get the engine turning faster or the power will be all torque and no speed and Larry's prediction of gloom and doom might come true. A pair of BX belts can handle plenty of HP but not at such low speeds. After some research I found some interesting things about this monster. There are actually two rotors on the same shaft. One is high power permanent magnets and the other is a regular Lundell claw & field coil. With the field coil off the magnets will drive the alternator to 200 amps at 4,000 RPM. If more power is needed to maintain voltage the field coil is energized to add to the flux and produce up to 305 amps. If less power is needed the coil is reversed to cancel out the flux field. Net result is a 70% increase in efficiency and a corresponding reduction in heat build up but to get minimum output the field coil has to be driven at full power backwards. The down side is you can't use a 3 stage regulator. This puppy is designed to crank out power for lights, inverters and equipment. Control is strictly on the output voltage so it stays in bulk stage until the batteries can't take any more. This is going to take some more thought. For the price though it would be a good temporary high output spare. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "Andina Marie" wrote in message ps.com... I hope you were increasing both pulleys so the alternator RPM was the same? If the alternator sucks up too many horsepower, especially when docking or emergencies, a field disconnect switch can be added to remove the load temporarily. |
Can an alternator be to big?
Glenn Ashmore wrote:
Actually reducing the alternator RPM is the idea. This thing puts out 200Amps at an alternator speed under 2000 RPM. With the pulleys I have now that is an engine speed of about 800 RPM. I need to get the engine turning faster or the power will be all torque and no speed and Larry's prediction of gloom and doom might come true. A pair of BX belts can handle plenty of HP but not at such low speeds. Actually, the alternator will put out whatever the battery and loads require. Unless you are charging a huge battery bank and/or have 200 A load connected to it, it won't put out that much. Given the electrical (and mechanical) losses, the input HP will be whatever are needed to provide the electrical output. The larger alternator will have lower electrical losses, but higher mechanical. All in all, this unit won't present a mechanical load significantly different than a smaller alternator. After some research I found some interesting things about this monster. There are actually two rotors on the same shaft. One is high power permanent magnets and the other is a regular Lundell claw & field coil. With the field coil off the magnets will drive the alternator to 200 amps at 4,000 RPM. If more power is needed to maintain voltage the field coil is energized to add to the flux and produce up to 305 amps. If less power is needed the coil is reversed to cancel out the flux field. Net result is a 70% increase in efficiency and a corresponding reduction in heat build up but to get minimum output the field coil has to be driven at full power backwards. This unit must be matched to the appropriate regulator. If you didn't get one with the alternator, the deal may not have been that good. The down side is you can't use a 3 stage regulator. This puppy is designed to crank out power for lights, inverters and equipment. Control is strictly on the output voltage so it stays in bulk stage until the batteries can't take any more. This is going to take some more thought. For the price though it would be a good temporary high output spare. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "Andina Marie" wrote in message ps.com... I hope you were increasing both pulleys so the alternator RPM was the same? If the alternator sucks up too many horsepower, especially when docking or emergencies, a field disconnect switch can be added to remove the load temporarily. -- Paul Hovnanian ------------------------------------------------------------------ Klein bottle for rent -- inquire within |
Can an alternator be to big?
"Paul Hovnanian P.E." wrote Actually, the alternator will put out whatever the battery and loads require. Unless you are charging a huge battery bank and/or have 200 A load connected to it, it won't put out that much. Given the electrical (and mechanical) losses, the input HP will be whatever are needed to provide the electrical output. The larger alternator will have lower electrical losses, but higher mechanical. All in all, this unit won't present a mechanical load significantly different than a smaller alternator. That's just it. There will definitely be a heavy load on it. When it cranks up every morning it will be seeing a 900AH battery bank ready to take the first 225 amps in bulk mode. This unit must be matched to the appropriate regulator. If you didn't get one with the alternator, the deal may not have been that good. It has the regulator built in. Pretty interesting one too. Even has a battery voltage sense connection. However the regulator does not have a way to change from bulk to absorption to float modes and there is no equalization. The shore power charger can handle the equalization and with my normal use pattern of 50% to 85% charge will rarely need float except at the dock but it would be nice to have optomized bulk and absorption ability. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
Glenn Ashmore wrote: I have been offered a really good deal on a high amp (325 amp) fire engine alternator by the city vehicle maintenance shop. It was purchased as a test unit but due to some budget cutbacks ended up being to expensive to equip the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and 275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp Leece Neville as a spare. My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk charge. Is my Xantrex smart regulator going to keep this monster from cooking my battery bank? -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com Everything you attach to the engine reduces the HP output. How much, good question. But having an alternator that is far bigger than your needs is a waste. Additionally, to make use of that power you need to get it to the battery banks. If the wire between the alternator and battery is too small to handle the current, or the wire between the battery and load center (electrical pannel) is too small, it could burn up under a heavy load if it's not fused properly. Your probably going to end up cooking something, lets hope it's not the boat while your on it. Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. John |
Can an alternator be to big?
"Capt John" wrote Everything you attach to the engine reduces the HP output. How much, good question. But having an alternator that is far bigger than your needs is a waste. Additionally, to make use of that power you need to get it to the battery banks. If the wire between the alternator and battery is too small to handle the current, or the wire between the battery and load center (electrical pannel) is too small, it could burn up under a heavy load if it's not fused properly. Your probably going to end up cooking something, lets hope it's not the boat while your on it. Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. No real problem there. Because if the higher efficiency the HP charts say it will take less power than the 200A Leese Neville that is in there now. I have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel. At idle speed it will theoretically put out up to 240 amps which will cover the 225A the battery bank needs in bulk mode with a little left over for house loads. The alternator is an Eco Tech 305. Apparently they are becoming popular with the commercial fishing boats in the NW. The regulator is set for 14.4 volts so while it may take a little longer in bulk mode it will be just right for absorption. I just need to figure a way to turn it off when motoring through a couple of days of no wind. Not a good idea to hold a fully charged battery at 14.4V for very long. Go2Marine has them on their site listed at $2K. The city is asking $375. I think I am going to take them up on it. :-) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... --------- Press 1 for English Press 2 to disconnect until you learn English |
Can an alternator be to big?
There used to be a manual alternator regulator called an Automac, sold by
Weems & Plath - This allowed the alternator output to be manually adjusted. These are no longer sold, but perhaps someone else sells something like that? Or perhaps drive it through a clutch that can be disengaged and keep a smaller alternator in service? I can understand that the price is attractive, but I would be careful with that beast! Unless of course, if you plan on doing some welding ;) Usually better to have multiple smaller units. Ventilation and cooling may need to be addressed - will you get enough cooling in your engine room as compared with the intended installation for those units? BUT, if you have the HP to drive it, it does sound like an interesting unit - especially the low speed output. GBM "Glenn Ashmore" wrote in message news:ulwug.165$ok5.148@dukeread01... No real problem there. Because if the higher efficiency the HP charts say it will take less power than the 200A Leese Neville that is in there now. I have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel. At idle speed it will theoretically put out up to 240 amps which will cover the 225A the battery bank needs in bulk mode with a little left over for house loads. The alternator is an Eco Tech 305. Apparently they are becoming popular with the commercial fishing boats in the NW. The regulator is set for 14.4 volts so while it may take a little longer in bulk mode it will be just right for absorption. I just need to figure a way to turn it off when motoring through a couple of days of no wind. Not a good idea to hold a fully charged battery at 14.4V for very long. Go2Marine has them on their site listed at $2K. The city is asking $375. I think I am going to take them up on it. :-) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
This thing uses a J-180 mount same as the Leece Neville so it will basically
be a drop in. Also supposed to generate less heat so the duct work I installed for the LN should be more than adequate. The weird thing about this alternator is that the primary magnetic field is from the permanent magnets on the rotor so as long as it is turning it is generating power. The way you turn it off is to run the field current in reverse to cancel out the magnets. That greatly increase the efficiency but means it can't use a normal external regulator. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "GBM" wrote in message ... There used to be a manual alternator regulator called an Automac, sold by Weems & Plath - This allowed the alternator output to be manually adjusted. These are no longer sold, but perhaps someone else sells something like that? Or perhaps drive it through a clutch that can be disengaged and keep a smaller alternator in service? I can understand that the price is attractive, but I would be careful with that beast! Unless of course, if you plan on doing some welding ;) Usually better to have multiple smaller units. Ventilation and cooling may need to be addressed - will you get enough cooling in your engine room as compared with the intended installation for those units? BUT, if you have the HP to drive it, it does sound like an interesting unit - especially the low speed output. GBM "Glenn Ashmore" wrote in message news:ulwug.165$ok5.148@dukeread01... No real problem there. Because if the higher efficiency the HP charts say it will take less power than the 200A Leese Neville that is in there now. I have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel. At idle speed it will theoretically put out up to 240 amps which will cover the 225A the battery bank needs in bulk mode with a little left over for house loads. The alternator is an Eco Tech 305. Apparently they are becoming popular with the commercial fishing boats in the NW. The regulator is set for 14.4 volts so while it may take a little longer in bulk mode it will be just right for absorption. I just need to figure a way to turn it off when motoring through a couple of days of no wind. Not a good idea to hold a fully charged battery at 14.4V for very long. Go2Marine has them on their site listed at $2K. The city is asking $375. I think I am going to take them up on it. :-) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460 @p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... Doesn't the CG requirement kick in only for gasoline engines? I doubt the insurance company could walk if the engine is diesel. Chuck |
Can an alternator be to big?
chuck wrote: Larry wrote: "Capt John" wrote in news:1153072859.862252.17460 @p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... Doesn't the CG requirement kick in only for gasoline engines? I doubt the insurance company could walk if the engine is diesel. Chuck |
Can an alternator be to big?
chuck wrote: Larry wrote: "Capt John" wrote in news:1153072859.862252.17460 @p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... Doesn't the CG requirement kick in only for gasoline engines? I doubt the insurance company could walk if the engine is diesel. Chuck The CG requirement is for diesel as well, diesel fuel burns quite well. Cracked high pressure diesel fuel lines can produce a very fine fuel mist, and it makes for one hell of a fire if it hits a spark or a hot dry turbo. Give an insurance company an excuse to walk away from paying on a loss and watch how fast they run. That's what they pay their people to do. I looked quickly at my Cat alternator part numbers, they look like differant part numbers than the truck numbers in the catalog. It just isn't worth it. |
Can an alternator be to big?
The surveyor that my insurance company hired to monitor my progress has seen
the Leese Neville which is not "USCG approved" and accepted it with out reservation. Actually neither 46 CFR 176 or 46 CFR 183 require approval of alternators in diesel powered environments. The only source I can find that recommends using only marine approved alternators is our friend David Pasco and he even has the reference to the requirements wrong. J1527 is specific to hose standards, not alternators. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "Capt John" wrote in message ups.com... chuck wrote: Larry wrote: "Capt John" wrote in news:1153072859.862252.17460 @p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... Doesn't the CG requirement kick in only for gasoline engines? I doubt the insurance company could walk if the engine is diesel. Chuck The CG requirement is for diesel as well, diesel fuel burns quite well. Cracked high pressure diesel fuel lines can produce a very fine fuel mist, and it makes for one hell of a fire if it hits a spark or a hot dry turbo. Give an insurance company an excuse to walk away from paying on a loss and watch how fast they run. That's what they pay their people to do. I looked quickly at my Cat alternator part numbers, they look like differant part numbers than the truck numbers in the catalog. It just isn't worth it. |
Can an alternator be to big?
Capt John wrote:
chuck wrote: Larry wrote: "Capt John" wrote in news:1153072859.862252.17460 @p79g2000cwp.googlegroups.com: Also, if it's not CG approved, and you have a fire because of it, your insurance company is going to walk away, it's your problem. I'd stick with the normal marine alternator if I was you. I think THAT is a very important point, too.... Doesn't the CG requirement kick in only for gasoline engines? I doubt the insurance company could walk if the engine is diesel. Chuck The CG requirement is for diesel as well, diesel fuel burns quite well. Cracked high pressure diesel fuel lines can produce a very fine fuel mist, and it makes for one hell of a fire if it hits a spark or a hot dry turbo. Give an insurance company an excuse to walk away from paying on a loss and watch how fast they run. That's what they pay their people to do. I looked quickly at my Cat alternator part numbers, they look like differant part numbers than the truck numbers in the catalog. It just isn't worth it. Capt. John, I'd really like to see a cite for the specific USCG regulation that requires ignition-protected alternators on diesel engines. 33 CFR 183.410 addresses only gasoline, and even then gives a pass if the gasoline is on the other side of a bulkhead, etc. Here is the applicability paragraph (183.401) for ignition protection: (a) This subpart applies to all boats that have gasoline engines, except outboard engines, for electrical generation, mechanical power, or propulsion. FWIW, I'm not advocating anything and am making no judgment here on what is and isn't worth it. I'm simply seeking clarification on what the regs actually say. Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Can an alternator be to big?
Glen,
Have you considered biasing the voltage sense line, to adjust the regulator output voltage? Peter Albright, Tampa, FL "Glenn Ashmore" wrote in message news:BV3ug.44$ok5.9@dukeread01... "Paul Hovnanian P.E." wrote Actually, the alternator will put out whatever the battery and loads require. Unless you are charging a huge battery bank and/or have 200 A load connected to it, it won't put out that much. Given the electrical (and mechanical) losses, the input HP will be whatever are needed to provide the electrical output. The larger alternator will have lower electrical losses, but higher mechanical. All in all, this unit won't present a mechanical load significantly different than a smaller alternator. That's just it. There will definitely be a heavy load on it. When it cranks up every morning it will be seeing a 900AH battery bank ready to take the first 225 amps in bulk mode. This unit must be matched to the appropriate regulator. If you didn't get one with the alternator, the deal may not have been that good. It has the regulator built in. Pretty interesting one too. Even has a battery voltage sense connection. However the regulator does not have a way to change from bulk to absorption to float modes and there is no equalization. The shore power charger can handle the equalization and with my normal use pattern of 50% to 85% charge will rarely need float except at the dock but it would be nice to have optomized bulk and absorption ability. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
"Peter Albright" wrote in message news:u2fvg.14644$A8.3191@trnddc02... Glen, Have you considered biasing the voltage sense line, to adjust the regulator output voltage? I have been thinking about that. Looks like that would be the only way to control it. The internal regulator is set to maintain 14.4V on the sense line. Boosting the sense line 1.2V would bring the output down to a safe 13.2V float. You could actually put a microprocessor to sense the battery voltage and bias the alternator sense to do everything a "smart" regulator does but that would be more work than I have time for. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Can an alternator be to big?
Glenn Ashmore wrote:
"Paul Hovnanian P.E." wrote Actually, the alternator will put out whatever the battery and loads require. Unless you are charging a huge battery bank and/or have 200 A load connected to it, it won't put out that much. Given the electrical (and mechanical) losses, the input HP will be whatever are needed to provide the electrical output. The larger alternator will have lower electrical losses, but higher mechanical. All in all, this unit won't present a mechanical load significantly different than a smaller alternator. That's just it. There will definitely be a heavy load on it. When it cranks up every morning it will be seeing a 900AH battery bank ready to take the first 225 amps in bulk mode. This unit must be matched to the appropriate regulator. If you didn't get one with the alternator, the deal may not have been that good. It has the regulator built in. Pretty interesting one too. Even has a battery voltage sense connection. However the regulator does not have a way to change from bulk to absorption to float modes and there is no equalization. The shore power charger can handle the equalization and with my normal use pattern of 50% to 85% charge will rarely need float except at the dock but it would be nice to have optomized bulk and absorption ability. That could be a problem. If you could tweak the voltage setting down a bit, you could slow down the battery charge rate and the resulting engine load. Petes's suggestion is pretty good. Put in some current sensing on the gen. output and use that to bump the V sense line up as the generator output approaches a setting suitable to your prime mover. You'll need a gain control to set the V bias per amp load and set it so that the system remains stable. -- Paul Hovnanian ------------------------------------------------------------------ Have a pleasant Terran revolution. |
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