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How quiet is Northern Lights 5 kw genset

Discussion in 'Generators' started by Delfin, May 14, 2015.

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  1. Delfin

    Delfin Member

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    I would appreciate hearing from anyone with a sound enclosured 5 kw genset. I currently have a 20 kw that was on the vessel when I purchased her, but want a smaller unit to charge batteries on the hook without having to listen to the 20 kw. So I am thinking about a 5 kw NL and would welcome any thoughts from those with a similar unit. Mine will be in a well sound insulated ER. So, how do you like yours? Is it as quiet as snowfall, as noisy as a Antonov 225 on take off, or somewhere in between?
  2. olderboater

    olderboater Senior Member

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    The manufacturer could give you actual decibel levels but my best guess would be mid 60's which can be reduced perhaps 5 decibels or so with their Sound Shield.

    Of course how this transfers to the rest of your boat depends on many other factors of sound insulation.
  3. HTMO9

    HTMO9 Senior Member

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    First a statement to start with: In my opinion, the Northern Light Marine Generators are of very good quality and are very long lasting hardware.

    But approaching this subject from the noise level point of view, they are not state of the art anymore. Northern Light is using liquid cooled Lugger diesel engines, running at 1.800 RPM (for 60 Hertz) and air cooled alternators for the electrical end. That is simple and straight forward machinery. But due to the air cooled alternator, the sound capsule has to have pretty big openings for the airflow of the alternator cooling fan.

    Even mounted inside one of those sound enclosures, those generators are quite noisy. With an well insulated engine room, you might be able to reach 65 or 60 db in Salon above the engine room but within the engine room at least 75 to 78 db. This is inherent in the system and can not be lowered.

    Below the Northern Light sound box with the 5 KW Genset. Note the air gates and the relatively big 3 cyl. Diesel engine. Weight including box is 421 lbs.

    M673L3_enc.jpg

    But there are little Gensets on the market in the 5 to 6 Kw range, with liquid cooled engines and alternators (using the same cooling circuit) and totally enclosed sound boxes. Those diesel generators are far more quiet and they are available as 1800 RPM and 3600 RPM version. Because they do not make so much noise, you can take a smaller engine with higher RPM, which means, they are much smaller and of light weight. And even with the higher RPM they have an TBO of 10.000 hours. Which means, with the average leasure type anual usage of 500 to 800 hours, they live longer, than you most likely own the boat.

    Whisper Power (Mastervolt) and Fischer Panda are only two names in this field.

    But as the OP indicates, he has an inverter setup in his boat and only wants to use the Genset for battery charging. So, why producing 120 Volt or 220 Volt AC and then only feed a battery charger which converts the AC into DC loading current (coefficient of performance C.O.P.!!!!). Just buy a variable speed, lightweight 12 Volt or 24 Volt DC Diesel generator and directly produce the neccessary DC amps with the Power and RPM needed for this setup and loading state of the battery bank and feed the rest into the highly efficent inverter.

    The Fischer Panda AGT-DC 5000, variable speed 5 KW Generator for example produces less than 60 db in the engine room during peak RPM and load and app. 55 db in the average. He is only less than 2 ft in length, width and height and has a weight of app 300 lbs. He is automatically started and stopped by the battery watch module and most likely will run only two times 1,5 hours a day, to keep the batteries alive. You will not hear him in the salon above at all. May be 2 sec. of very light vibrations, when he (cold) starts.

    I have a bigger version of this type of Generator as a Stby and night Generator in my large sail boat. My engineer and me and my guests love him.

    AGT-DC 5000.jpg

    The Fischer Panda AGT-DC 5000 uses a little 0,5 Liter 2 cyl. Kubota engine and the liquid cooled FP DC 12 Volt or 24 Volt alternator. With the above mentioned usage, may be 1 gallon or 2 of diesel a day.

    I know, those Whisper Power and Fischer Pandas are available in the US and I do not believe, they are as expensive or even more expensive than a Northern Light 5 KW AC Genset.

    Just my 2 (Euro) cents.
  4. olderboater

    olderboater Senior Member

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    In the smaller generator range, as low as 6 kw at 60 hz (5 kw at 50 hz), we have an 8 kw Kohler which we've been very pleased with too. I don't know how it compares sound wise to the ones mentioned by HTM. As he alludes, small isn't really where Northern Lights is targeting.
  5. Capt J

    Capt J Senior Member

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    I wouldn't go with a fischer panda. I have a friend that is repairing them in sailboats all of the time. They are noisy and transmit vibration through the engine mounts and such. They have a belt driven electrical end on a lot of them.

    I would go with a little bigger than a 5kw. Yeah you just want to charge batteries, but it would also be nice to have capacity to run the water heater or something else at the same time, if not even to use a couple of burners to cook with. I would go large enough to get into a 2 cylinder diesel which inherently will be a lot less vibration and noise than a 1 cylinder. Kohlers and the new Onans are both very quiet. Northern lights are too and their "old" technology has worked very well and lasted a very long time and proven. While I cannot say that I've dealt with a Northern lights so small, I can tell you in the ones I've dealt with, with a sound shield, you could be standing in front of one in the engine room and have a normal conversation with someone without raising your voice.
  6. HTMO9

    HTMO9 Senior Member

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    Capt J, I do agree with you most of the time but this time you are just wrong or you mixing something up.

    If a diesel generator is transmittig noise through the hull, he is installed the wrong way. And there never was and there is no, I say again no Fischer Panda Genset with the electrical end being belt driven. At least not since I am involved in boating and this company was founded in the early eighties in Milow232 hometown in Germany. The only belt driven electrical piece of machinery on them, is the little additional 10 amp alternator on the front end for charging the generator starter battery and holding the fuel shut off solenoid.

    And the only single cylinder Fischer Panda Gensets available, are the basic AGT genis, using the Kubota horizontal diesel and the old Faryman 1 cyl diesel. But I was not talking about those old bangers. I was talking about the AGT-DC variabel speed 2 cyl Kubota diesel with the alternator mounted directly on the crankshaft (like on all other Fischer Panda or Whisper Power Generators) but with intergrated liquid cooling.

    I believe, your point of view is going bigger is always better. But then you need one of those load banks or one of Marmots exhaust gas heaters, if the big genset is running mostly under low load. A modern variabel speed genset is running always at optimum load and does not have to be oversized when built into a pleasure boat.

    And the OP was asking for the Northern Light 5 KW noise level and not Kohler and Onan. But both of them are still noisier than a fully capsuled and correctly mounted Fischer Panda or Wisper Power fully watercooled Genset.

    I am sure, you can talk normally in an engine room with a Genset working at 78 db but 55 db is equivalent to flattering of leaves
    at light wind. And a 3 db lower noise level is half the noise for the human ear.

    I am not on any missionary duty here on the forum for selling European goods at all. But sorry, not everything is better in quality and technology, just because it is made in the US! I buy my private Jets and Helicopters, even some of my firewood (Hickory :)) only in the US, because its the best available with the best service and support. I buy my sailboats in the Netherlands, because they are the best custom build sailboats in the world and my cars in Germany, because I like them :p.

    There are decades in technology advancements between an mechanically governed and controlled little Northern Light generator with a Lugger engine and an conventionell air cooled synchron dynamo of WW II technology and an electronically controlled Fischer Panda diesel with an watercooled, permanent magnet, self-exciting, brushless, asynchron dynamo or an direct DC Battery charging dynamo.

    There are many cases, where I would still buy a Northern Light Generator, a Lugger propulsion engine or an Onan or Kohler Genset. But when shopping for a little as 5 to 8 KW secondary or battery charging genset for marine leasure purposes, Whisper Power or Fischer Panda are the best stuff on the market worldwide, period. Bad installement, bad or no maintenance or abuse can turn the most perfect technical piece of kit into junk.

    From 25 or may be 45 up to 100 KVA, I would go for Cummins / Onan, above that for an MTU, MAN or Caterpillar/MAK diesel engine with an Leroy Somere or may be Stamford electrical end. Thats what we do in our commercial world and we were never proven to be wrong.

    Just my 2 (Euro) cents
  7. olderboater

    olderboater Senior Member

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    Well, you say he was asking about Northern, not Onan or Kohler, he wasn't asking about Whisper Power or Fischer Panda either. We're all just offering comparative information to assist him. Now as to Fischer Panda, I've never owned one. However, I have read quite a few threads regarding them and problems and issues with them on multiple other sites. Quite a few were sailors who either chose or had in the boat they purchased Fischer Panda because of the reasons you mention. Size and weight are major advantages for sailors. However, the overall views expressed toward them have been extremely negative and would strongly discourage me from one. Now, admittedly many of these may not be the specific units you're suggesting but some are.

    My actual experience is with four Northern Lights, all larger, 25 kw to 99 kw, and very pleased with all, but haven't owned a smaller one. However, I do own 4 Kohler units including 8 kw and find them quiet and trouble free. Still a very small sampling of experience.

    So while I respect your knowledge and experience, I've read a lot of complaints on Fischer Panda. Perhaps installation or maintenance, perhaps certain units, but enough that it does cause me some concern.

    For actual sound measurements, I would suggest the OP contact the manufacturers of the generators he's considering. There are also other tradeoffs which you suggest. Small generator at high rpm vs. larger generator at low rpm is certainly one.

    I do have one other question regarding Fischer Panda. That is how extensive a service network do they have in the US? I ask as they don't disclose that information on their website. Do you know? I know they claim the smallest, lightest, quietest and for many applications that could be a great advantage.
  8. HTMO9

    HTMO9 Senior Member

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    Bad or no service for equipment in the specific area of usage would be definately a reason for me not to buy a specific equipment. If there would be no service for Fischer Panda or Whisper Power Gensets in parts of the US, dont buy them.

    Specific early Fischer Panda AGT constant speed 3000 or 3600 RPM Gensets had some issues in sailboats in the beginning. Especially the 1 cylinder Kubota and the little 1 cylinder Faryman were (and still are) rough little bangers which suffer from low load and if mounted incorrectly (wrong mounting angle and the riser and water seperator not mounted and sized correctly), the are having problems with water ingress and low lub oil supply, when heeling. But the newer 2, 3 and 4 cylinder non turbo Kubotas are great engines and the electrical end works flawless both for the constant speed and the variabel speed ones.

    On the larger ones above 45 KVA, I do not like the choosen engines, thats why I said Onan. I had more than 30 Fischer Panda Gensets of different size in boats and camping busses in my family in the last 30 Years but the only issue we had, was the little drive belt for the raw water pump in this 1 cyl. Kubota. A great little engine but only for stationary (straight and level) duties i.e. Mobile homes and only with single cooling circuit with keel cooling or radiator.

    Those very little Diesel Gensets need a little more care and observation than those heavy and commercial rated bangers. But they are bought, because they small, light, quiet and fuel efficient. They are not build for 24/7 duty or 8760 hours a year. It is pleasure boat equipment.

    They have larger, havy continous duty versions up to 200 KVA in their portfolio now but no standing in the market jet.
  9. olderboater

    olderboater Senior Member

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    This is one of the many pieces of equipment where location might play a role in the decision. With the OP there are other interesting elements. For instance, what is the age of his 20 kw unit and does it have a sound shield? How much space does he have for another unit? How well can he suppress the sound transferring from the engine room as it seems that's an issue now. I'd have to think if the 20 kw generator is bothersome, his engines may well be too.

    I also know a lot of sailors and trawler owners who are addressing their needs similar to the OP's with Honda portable generators. Not my recommendation but seems quite popular.
  10. Capt J

    Capt J Senior Member

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    I'm looking at the Fischer Panda site. First off all of the variable speeds are only shown at 50HZ, that being said are they even offered in 60 hertz? The OP is located in WA so 98% sure he needs 60hz. Closest variable speed generator offered to what the OP is looking for is the PMI5000i which is a 4KW at 50hz, which should be a 5kw if it can be converted to 60hz, it is a 1 cylinder. Next closest size is a 6.0 KW which would be about a 7.5KW if it could be converted to 60hz. The alternators are air cooled on these and the closest size with a fresh water cooled alternator is 6.8KW at 50 HZ. Something about having water running through an alternator which is producing electricity rubs me the wrong way.

    The Onan 5kw is 71Decibles. The Fischer panda is rated at 51 Decibles but is even quieter when it's not running =). I cannot find any info on the sound level of the NL generator. 71DB is not very loud if the engine room is insulated. I would want an 1800 rpm generator set and not a 3600rpm set, personally.
  11. HTMO9

    HTMO9 Senior Member

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    The generator I was talking about, the AGT-DC 5000, is a very simple variable speed 12 volt or 24 Volt DC battery charging generator. Exactly what the OP was looking for. So no 50 or 60 Hertz. And it is a 2 cylinder Kubota with integrated liquid cooling of the engine and the dynamo / alternator (or whatever you want to call it). And he works fine for years now, believe me. And it does never run at 3600 RPM.

    The 5000 i and its smaller and bigger brothers are variable speed AC generators which produce 400 Volt Foucault current for an associated special inverter (either integrated in the box or external), which consequently produces ideal sinus 230 Volt 50 Hertz or if wanted 60 Hertz AC. The bigger ones even produce 400 Volt 3-Phase AC 50 Hertz. The 60 Hertz versions might not be available in the US jet but this type of genset was not part of my post.

    This is a total different type of generator line and state of the art and the future type of boating generator. They deliver ideal and most stable AC power, are small in size, always operate at optimum load and can be combined as wanted, in order to build generator arrays. You can even combine different sizes of i-series gensets. We are just planning two of those 25 i (4 cyl. normal aspiratede 1,5 liter Kubota engines) in my sons new boat at the moment. And those ones will also never run at 3600 RPM even at 60 Hertz.

    Btw. it is the same principle Honda uses for its 10i, 20i and 30i portable aircooled gasoline generators. Here, the inverter is build in. Many other companies are now starting to use this principle for their generators also, because it works so perfect.

    I do not believe, Fischer Panda has invented this system. As far as I know, it is used in the military in conventionell submarines and aircrafts for quite some time now.

    In some years time, constant speed AC generators with diesel engines with mechanical injection pumps and control and running at 1500 or 3000 RPM for 230/400 Volt 50 Hertz or at 1800 or 3600 RPM for 60 Hertz, with dynamos with the technology of the Alva Edison and Nikola Tesla aera will be a thing of the past. At least in the pleasure yacht business and with a little more time in the smaller commercial world too. Fuel prices and exhaust gas regulations and last but not least the market will dictate that.

    What the big two stroke heavy fuel oil world will be doing, I do not know. But my confidence in the future EPA and IMO rule making is pretty good.

    We have a full DC diesel-electric cargo vessel in the pipeline at the moment with big 4-stroke MDO generators using the same principle. And here, the dynamos are liquid cooled also. And they go from 500 RPM to 1000 RPM only. And we have 50 Hertz, 60 Hertz and 400 Hertz and 115 Volt, 230 Volt, 400 Volt, 440 Volt (the 440 Volt 60 Hertz is for the reefer boxes only) and 690 Volt in the onboard electrical system. And the system leading electrical company is absolutely sure, it will work, because they have done it before.

    Feel free to continue. It is getting me interested.
  12. Capt J

    Capt J Senior Member

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    The OP is looking for a genset, not a variable speed battery charger. My guess is because he'd like to have a minimal amount of AC power as well for a tv, microwave, toaster oven, etc.
  13. HTMO9

    HTMO9 Senior Member

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    Dear Capt J, Sir!

    In this case, I must have totally misunderstood his original post with my humble english and your proposals are of course the only correct ones, Sir.

    Please accept my apologies for taking so much of your precious time and server space of this great forum with my most stupid and far to long posts without any expertise and substance.

    With most submissive adoration

    HTM09
  14. PacBlue

    PacBlue Senior Member

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    To make the most quiet NL installation I recommend the following:

    Resilient mount the entire enclosed genset on a base frame or available ships' structure, Soundown can help you with the mounts, sizes, pattern, etc. http://www.soundown.com/IM.htm
    This will in fact provide a nice and quiet double isolation system, as the unit already has its' own resilient mounts within the sound enclosure.
    Next, use a Waterlift Muffler that separates the Exhaust Gas and Water to knock the exhaust noise down. http://www.centekindustries.com/product_descriptions.html
    Use isolation mounts for those as well. You will get a lot of bang for the buck, so to speak, but with ultra quiet results, like "snow falling"!

    We used this approach on a custom 130MY and had the owner onboard the vessel while it was still high and dry at the shipyard. We plumbed the genset, ran water and fuel to it and test ran it for quite a few hours. The owner was standing on the deck directly about the genset (85kW) and was complaining that the shipyard was behind schedule and was expecting the genset to be running, until someone informed him that it was indeed running, directly below his feet!
  15. leeky

    leeky Senior Member

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    Delfin hasn't been on YF since he started this thread. So, if you all want to continue this conversation and design the perfect set up for his boat, this is where you can find what he has: http://delfin.talkspot.com/ There's a section that describes the boat's electrical system. Have fun.:)
  16. Delfin

    Delfin Member

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    Many thanks. The Fischer Panda seems to have its adherents, but it also seems like a lot of people have issues with them. NL, Onan, not so much. What makes no sense to me at all is the price differential between the Onan in this size range - around $3,500, and a NL, Panda, Westerbeke which all cost more than $10k. The limiting factor is the footprint without some fairly expensive modifications to get a larger unit into the E/R.

    Your comment on just going with a DC generator is well taken. A local company - Ample Power - makes a 175 amp 24v unit driven by a Kubota. The only concern is longevity, but if I got 6,000 hours that would be fine.
  17. Delfin

    Delfin Member

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    The size of all the 5kw units I've looked at seem pretty similar. The Onan is slighter bigger than the NL, and as I recall the Panda occupies around the same footprint. Where space savings come in appears to be with DC units that are only turning an alternator.

    Many thanks.
  18. Delfin

    Delfin Member

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    Interesting that the Whisper Power is quite a bit larger than the Northern Lights - 32" x 21" x 23" compared to 28" x 19.5" x 20". I know that doesn't sound like much but the extra bulk would make getting a Whisper into the ER pretty tough.

    Couldn't agree more on the importance of installation if quiet is what you want. I get no vibration from the 20 kw, just noise because it isn't sound enclosed, and its, well 20 kw.

    Thanks again.
  19. Delfin

    Delfin Member

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    Allegedly, Fischer's US service levels are legendary, and not in a good way. Or so the threads I have read on them would indicate.
  20. olderboater

    olderboater Senior Member

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    Wouldn't adding a sound shield to it be a good idea as well? Or are your limited space and design wise?