Choosing a good generator

1679111219

Comments

  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    Re: Choosing a good generator

    Related to hour meters, I picked up a very nice quality Grasslin (German) vibration hour meter for my diesel generator. If memory serves me right, these normally sell for close to $200 each. These are surplus and they are new but they have hours on them. They must have been stored or transported with enough vibration, that they accumulated some hours. Mine came with 30 hours on it. Neat thing is that these don't require any electrical power to operate. For only $11 with $5 shipping, hard to beat. I also bought a cheap $7 meter mount bracket on Fleabay as well. In case this helps anyone else, here it is. Hopefully this doesn't violate any forum policies. Just trying to help out.

    http://www.ebay.com/itm/110976156226?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

    For more details, here's the Intermatic site that sells these Grasslin meters under their name.

    http://www.intermatic.com/Products/HourMeters/Vibration/RZ_Series/RZ52HU.aspx
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Choosing a good generator

    Looking at the wiring diagram (if this is the right PDF)--don't see an easy way to double the current at 120 VAC.

    Then your only choices would be a 240 to 120 VAC transformer of some sort...

    Or to get a ~25 amps @ 48 volt AC battery charger and connect that to the second 120 VAC circuit. And use both in parallel to recharge the battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • arby
    arby Solar Expert Posts: 107 ✭✭
    Re: Choosing a good generator

    Yeah, that's the one, and that's what I found out. I also saw in a Honda shop, some Honda generators that had a switch on them to pull from both sides, but I already had the EX5500 bought very reasonable slightly used. Had some electrical guys look at the diagram and they told me that I needed a transformer.
    Anyway, FWIW , when folks are looking at potential genny purchases, they should consider that the output numbers are somewhat misleading.
    Russell
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    arby wrote: »
    Anyway, FWIW , when folks are looking at potential genny purchases, they should consider that the output numbers are somewhat misleading.
    Russell

    Small generators don't generally have a prime rating and a standby rating like big gensets do. Honda will typically provide a "maximum" rating, which is the maximum the generator can put out for a short duty cycle. And they will provide a "continuous" rating, which is the same as a prime rating and must be de-rated for altitude and ambient temperature. I don't know that it's misleading - merely that most manufacturers rate their generators by the peak surge watts at sea level, not what it puts out continuous without overheating at some other altitude. In the end it's up to the consumer to know what they're buying, and to realize that a generator rated at sea level has to be de-rated at 4,000' elevation, or whatever.

    In the case of your inverter, there's a setting that limits the amount of amps the inverter can use for the internal charger. You evidently have that set to 25 amps. The ratio with the 5548 is 2:1. The max input amps for the charger is 35 and it will deliver 70 amps to the battery at that setting. It requires a generator capable of delivering 4.2 kVA at Power Factor 1.0 to use the full capability of the SW5548's charger. Without looking up the specs on your Honda, it should be capable of delivering that amount of power from the 240 volt plug with the transformer on it. However, if the inverter is set to only allow 25 amps being used for the charger, that's all you're going to get (50 amps at the battery), regardless of how big the generator is.
    --
    Chris
  • arby
    arby Solar Expert Posts: 107 ✭✭
    Re: Choosing a good generator
    ChrisOlson wrote: »
    Small generators don't generally have a prime rating and a standby rating like big gensets do. Honda will typically provide a "maximum" rating, which is the maximum the generator can put out for a short duty cycle. And they will provide a "continuous" rating, which is the same as a prime rating and must be de-rated for altitude and ambient temperature. I don't know that it's misleading - merely that most manufacturers rate their generators by the peak surge watts at sea level, not what it puts out continuous without overheating at some other altitude. In the end it's up to the consumer to know what they're buying, and to realize that a generator rated at sea level has to be de-rated at 4,000' elevation, or whatever.

    In the case of your inverter, there's a setting that limits the amount of amps the inverter can use for the internal charger. You evidently have that set to 25 amps. The ratio with the 5548 is 2:1. The max input amps for the charger is 35 and it will deliver 70 amps to the battery at that setting. It requires a generator capable of delivering 4.2 kVA at Power Factor 1.0 to use the full capability of the SW5548's charger. Without looking up the specs on your Honda, it should be capable of delivering that amount of power from the 240 volt plug with the transformer on it. However, if the inverter is set to only allow 25 amps being used for the charger, that's all you're going to get (50 amps at the battery), regardless of how big the generator is.
    --
    Chris

    I really do not know much about these things, but it came as surprise to me that a 4000 watt generator really can only put out 2000 watts at 120 through one outlet.
    As far as I can tell, to get the 4000 watts , one needs to use both 120 outlets, or the 240 outlet. That is what I am referring to on the "misleading" part.
    Thanks for the advice on the Amp settings, etc.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Choosing a good generator

    Well, to me is is not at all misleading. If one chooses to try to use only half of the generator's output, that is their choice. AND, in general, it is not good to use one half of the alternator's output at or near its full capability, and little or nothing on the other half (winding). This asymetrical load can cause voltage regulation and other problems, and is essentially wasting half of the genset's capability, IMHO.

    Chris, saw somewhere on the web, that Honda Eu series inverter gensets had a "Surge" rating for 20 minutes, this is at the maximum rated power. I asked a Honda dealer about this, and they did check with Honda USA, and reported, that yes, when new, that was the case at nominal sea-level. FWIW, not quite heresay. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    Vic wrote: »
    Chris, saw somewhere on the web, that Honda Eu series inverter gensets had a "Surge" rating for 20 minutes

    Our EM4000SX will also do this - it will deliver surge of 5.0 kVA for 10 seconds, 4.0 kVA for about an hour and 3.6 kVA continuous. The "maximum" rating of 4.0 kVA for our genset depends on the winding temp, not engine hp.

    I've pushed it to 4.0 kVA and at about 60-70 degrees ambient temp it takes an hour before the voltage starts to drop from the 120/240 nominal. That's the point where the windings have reached their maximum temp so resistance goes up and the voltage starts to drop so you can no longer get 4.0 kVA from it. You can continue to pull the same amps, but the voltage will gradually drop to 110/220 (or lower) instead of 120/240. If you cut the amp load back to 30 amps on a 120 volt load, then the voltage will go back up to 120.

    So that's basically what the "continuous" rating is all about - winding temp.
    --
    Chris
  • arby
    arby Solar Expert Posts: 107 ✭✭
    Re: Choosing a good generator
    Vic wrote: »
    Well, to me is is not at all misleading. If one chooses to try to use only half of the generator's output, that is their choice. AND, in general, it is not good to use one half of the alternator's output at or near its full capability, and little or nothing on the other half (winding). This asymetrical load can cause voltage regulation and other problems, and is essentially wasting half of the genset's capability, IMHO.


    I understand what you are saying, but I daresay that most folks that buy a generator are not aware of this and assume that a 4000 watt generator means 4000 watts, not 2 X 2000.
    I certainly don't wish to cause a controversy here. Just wish to point out that most people know very little about these things (me for example) and it came as a surpise when I found out.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Choosing a good generator
    arby wrote: »
    Well, to me is is not at all misleading. If one chooses to try to use only half of the generator's output, that is their choice. AND, in general, it is not good to use one half of the alternator's output at or near its full capability, and little or nothing on the other half (winding). This asymetrical load can cause voltage regulation and other problems, and is essentially wasting half of the genset's capability, IMHO.


    I understand what you are saying, but I daresay that most folks that buy a generator are not aware of this and assume that a 4000 watt generator means 4000 watts, not 2 X 2000.
    I certainly don't wish to cause a controversy here. Just wish to point out that most people know very little about these things (me for example) and it came as a surpise when I found out.

    A lot may depend on the way the generator is designed too. If the main determiner of the output power is the engine rating, then the manufacturer could choose to use slightly larger wire size on one or both stator windings to allow more than 1/2 (but still less than 100%) of the power to be drawn from one phase.

    My trusty (for occasional use, although cheap and noisy) Generac 4Kw generator provides three output connections:
    A 4/5 wire 240 volt twist-lock with 20 amp breaker,
    Two 20 amp 120 duplex outlets, one per phase, each with a 20 amp breaker, and
    One 3 wire, 120 volt twist-lock with a 30 amp breaker, driven from one phase.

    The manual recommends, sanely enough, that you not try to take output from all three at once, since there is no common overcurrent device which protects all three.
    And if you use the 30A 120V output, you are not supposed to use either of the 20 amp 120 volt outputs, even if you determine which one is on the opposite phase. Presumably the extra heating of taking 30 amps from one phase alone will not let you also draw anything (or at the least not the full 20 amps) from the other phase.

    My point is that although you will not get full power, you may safely get more than 1/2, depending on the generator head construction. As Vic said, there will still be consequences for voltage regulation, etc.
    If you want to get full output to a single 120 volt load, you will have to use a transformer. And not one which is too far oversized, since the idling current in the transformer primary will still take some VA and will lead to more heating in the generator windings.
    SMA SB 3000, old BP panels.
  • arby
    arby Solar Expert Posts: 107 ✭✭
    Re: Choosing a good generator

    "you will have to use a transformer. And not one which is too far oversized, since the idling current in the transformer primary will still take some VA and will lead to more heating in the generator windings. "
    More info that I didn't know. I went with a 10 KK transformer assuming that a little larger would be better.
    Hopefully this will not be needed too often, which was the case this past summer. I only caught the genny running twice and those happened to be the exercise times.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator

    I just wanted to say thanks to Chris Olson et al for making such a great informative thread on generators and integrating them more efficiently with battery based inverter systems! Really enjoyed reading all this and the expertise many brought to the discussion. I didn't see mentioned much about generator brands/types that are good for running sensitive equipment : such as network equipment, satellite or WiMax radios. Most people I come across have some or all of the above and other electronics that don't take too kindly to the grid power here yet alone a chinese pull start standby generator. What models have people had success with? I've tended to favour inverter type gensets for smaller systems or diesels with AVR for larger systems. It would be good to be able to recommend a good quality generator without inverter for battery charging that could run sensitive loads. Seems like a better option than an inverter style generator from what I've read on here if it can do it.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Choosing a good generator

    In general, the new/modern switch mode power supplies are pretty tolerent of variable power. Many modern Power Factor Corrected (PFC) power supplies will run from ~95 to 264 VAC ~45-66 Hz (sometimes up to 400 Hz), and even DC in that range.

    What can cause grief are generators with lots of RF (radio frequency) interference. Could range from the AC voltage regulator to ignition noise to other electronics (electronic throttle control, inverter+generators, local starting battery charger, automatic transfer switches, etc.).

    Unfortunately, those types of RF interference really need a spectrum analyzer to check for radiated (usually 30 MHz to 1 GHz or higher) and conducted noise (up to ~30 MHz if I remember correctly--been many years).

    With radios, "birdies"+Hash from AC (and DC) generators can be a real problem. Unless you do your own testing, it is almost "word of mouth" -- XYZ model 123 generator is good and ABC model 234 is bad.

    If you have some "HAMs" (amateur radio folks) in your area--They might be able to help you with finding some good choices or even doing some testing.

    And the frequencies that you will be using (i.e., HF in the 3-30 MHz band, VHF in 30-300 MHz, UHF 300 MHz - 3 GHz, etc.) will make a big difference...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    It would be good to be able to recommend a good quality generator without inverter for battery charging that could run sensitive loads. Seems like a better option than an inverter style generator from what I've read on here if it can do it.

    I can vouch for the Honda EM-SX series - they come in 4,000, 5,000 and 6,500 watt (peak) sizes. This would be the smallest one:
    http://powerequipment.honda.com/generators/models/em4000

    They do not have an inverter. They have an electronically controlled engine and generator head (no AVR - the control computer adjusts the generator field so there is no exciter winding) so they maintain perfect voltage and frequency at all times, short of extreme overload. And they will actually produce 125% of their rated output for 10 seconds and still maintain perfect 120/240 and 60 Hz. They are not cheap, but they're more than suitable for sensitive electronic equipment as well as continuous heavy loading on battery charging duty.
    --
    Chris
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator

    Thanks for the responses. I like the look of the Honda EM4000S but is there anything in the 2-3kWh range that would work without having to opt for an inverter type genset. Battery charging and gen support would be the obvious roles.
    Also I haven't seen anyone ask this but @ ChrisOlson what do you think of the effects on engine reliability/longevity when the generator is used for generator support? Won't this cause excessive wear as the generator has no time to warm up before it's made to power (heavy) loads? It sounds like you've got many hours off your Honda in this role but I just wanted to check if this is a consideration/detraction for using generator support. Thanks again for sharing your knowledge and experience!
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    Thanks for the responses. I like the look of the Honda EM4000S but is there anything in the 2-3kWh range that would work without having to opt for an inverter type genset.

    what do you think of the effects on engine reliability/longevity when the generator is used for generator support? Won't this cause excessive wear as the generator has no time to warm up before it's made to power (heavy) loads? It sounds like you've got many hours off your Honda in this role but I just wanted to check if this is a consideration/detraction for using generator support. Thanks again for sharing your knowledge and experience!

    There are no conventional generators in the 2-3kW size class, that I'm aware of, that have the necessary technology in them required to maintain the sort of output the Honda EM-series does. That size is pretty much considered casual consumer, non-commercial class so companies are going to be reluctant to spend much on engineering because they're competing at a price point with all the other generators in that size class. And typically the cheapest ones sell.

    Using a generator for peak load support on auto-start is hard on it, no doubt. Basically it starts, warms up for 15-20 seconds and goes to full load. Summer time operation with that type of duty, I don't think, is a problem at all for an air-cooled, splash-lubed engine with ball main bearings. In the winter time we do keep a 75 watt heat lamp shining on the cylinder barrel, head and carb so it starts within a couple compression strokes and has some heat in the cylinder. But winter is still harder on it.

    As far as the actual length of time, in hours, it will shorten the engine's life vs continuous rated load operation? I'd guess it will shorten its life some. However, an air-cooled, splash-lube engine is best suited to that type of duty vs a liquid-cooled, pressure-lubed design.
    --
    Chris
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Choosing a good generator
    ChrisOlson wrote: »
    Using a generator for peak load support on auto-start is hard on it, no doubt. Basically it starts, warms up for 15-20 seconds and goes to full load.

    My Generac is designed to take the full load within 2-3 seconds from the start. With XW there's a delay because it needs to qualify the generator, which probably takes 5-7 seconds (never tried to time that). So, it gives about 8-10 seconds between starting and applying full load. Do you think it'll increase generator longevity if I introduce an external delay between starting and loading?
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    NorthGuy wrote: »
    Do you think it'll increase generator longevity if I introduce an external delay between starting and loading?

    Definitely. Letting it reach proper operating temperature before applying load is always the best.

    But you have to realize that there's a difference between what some generators are "designed for" vs others. The Generac Guardian has a design operating life of 1,000 hours in standby duty. That will last most people that need standby power for grid outages more than 20 years.

    On the other hand, consider the 1.2-2.0 MW standby diesel generators used in hospitals and other critical care facilities that have a design life of 50,000 hrs between overhauls. Standby generators in any facility that has human life support systems are required by federal law to start and accept full campus load within 10 seconds of a power outage. And they have to be certified and tested under full load every 30 days. But a 3,500hp Cummins QSK60 diesel standby generator engine also has 12kW worth of block heaters and oil heaters on it that keep it at full operating temperature 24 hours a day, 365 days a year. So once it is installed, it is never thermal cycled.

    The thermal cycling and cold starting is what kills most engines. Approximately 85% of the measured wear in your engine occurs within the first few minutes after cold startup. So a generator engine that is used only for peak load duty (start it cold, immediate full load, short duration run time) on an off-grid power system is going to experience more wear in fewer hours than one that starts and runs for several hours at a time.
    --
    Chris
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Choosing a good generator
    ChrisOlson wrote: »
    Definitely. Letting it reach proper operating temperature before applying load is always the best.

    Thank you. I certainly can do a delay. How long do you think I should wait before applying loads? Does the wait time depend on the ambient temperature?
    ChrisOlson wrote: »
    The thermal cycling and cold starting is what kills most engines. Approximately 85% of the measured wear in your engine occurs within the first few minutes after cold startup. So a generator engine that is used only for peak load duty (start it cold, immediate full load, short duration run time) on an off-grid power system is going to experience more wear in fewer hours than one that starts and runs for several hours at a time.

    That is an interesting thought. So, if I try to start it every other day in winter (as opposed to every day) and let it run for longer, it'll last almost twice as long. I can try to arrange that.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    NorthGuy wrote: »
    Thank you. I certainly can do a delay. How long do you think I should wait before applying loads? Does the wait time depend on the ambient temperature?

    An air-cooled engine comes up to safe operating temperatures way faster than liquid cooled engines do. But it depends on the temperature of the air blowing over the cylinders and heads. At temperatures close to zero F it will never reach proper operating temperature without some way to regulate the temperature of the air being admitted to the engine's cooling fan. That is why I have gone to great pains to control that in winter time in my generator enclosure (and now our new powerhouse). I like to see the air being admitted to the engine's cooling system at around 70 deg F to get the cylinder head temp up to at least 250 degrees and oil temp at around 180 deg F.
    That is an interesting thought. So, if I try to start it every other day in winter (as opposed to every day) and let it run for longer, it'll last almost twice as long. I can try to arrange that.

    Yessir. You will definitely increase the useful life of your Generac if you can reduce the number of cold starts it has to go thru in its life. That is a pressure-lubed engine and the top end runs woefully short on lubrication flow during the first few minutes when it's cold. And what makes it worse is that it's usually been sitting for a long time between starts so the top end is "dry" anyway when you start it. The valve guides probably don't receive any lubrication, other than what has "clung" to the valve stem since the last run, for close to five minutes after a cold startup. And guess what the first thing is that I have seen go to pot on Generac OHVI engines that have a lot of hours? You guessed it - the valve guides and seats get so bad that the valves start to leak and burn an exhaust valve. They are LP and NG engines, and those fuels are very "dry" in the first place which compounds the problems with valves and seats.

    With the Generac also pay attention to how much loading you apply to it. They are designed for 50% continuous load with only short duration runs over 50%. And that is the way they are sized when installed by a professional installer for home backup power. The OHVI engines have a very low deck height and very short rods so they apply a lot of side pressure to the bore on the power stroke. Keeping that side pressure down will help prevent hammering out the small end of the rods and premature piston skirt failure or breakage.

    The Guardian series generators are decent for the price. But keep in mind that they are designed from the ground up to compete at a price point in box stores - Menards, Home Depot - you name it - sells them. They are not designed for what you are using it for. But applying a few "tricks" can help you get more life from it in your application. And another one of those "tricks" is installing a block heater on it. Generac, I'm pretty sure, makes one for it - not sure if it's the element type oil heater like the EcoGen has, or if it's a pad type heater. But it can make a big difference in cold weather and they only draw like 45-50 watts IIRC.
    --
    Chris
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Choosing a good generator
    ChrisOlson wrote: »
    But applying a few "tricks" can help you get more life from it in your application.

    Thanks Chris! These are very useful ideas. I'll try to create the best conditions for the Generac I can master.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    NorthGuy wrote: »
    Thanks Chris! These are very useful ideas. I'll try to create the best conditions for the Generac I can master.

    Another "trick" you could use in the winter when you don't get much solar and have to run generators more is to build a suitable temp-controlled enclosure for your Champion so you use it during peak draw times in cold weather when the load on your system goes over about 3 kW or so. Those times might not be very long. But even if it's for an hour it saves on batteries, probably providing even a little extra to put some amp-hours into them, gives you an opportunity to exercise the Champion now and then, and in the long term will save some run time on the Generac.

    The engine in your Champion generator, IMHO, is tougher than the Generac engine. On a cold start the Champion doesn't have to worry about pumping any oil to critical parts and having enough flow to insure adequate lubrication. The Champion engine has rotating tappets, steel crank and cam gears, steel governor parts, and it throws a lot of oil at the upper end (rockers, pushrods and valves) due the direction of rotation, which side of the crankcase the cylinder is on and how the "dipper" tosses oil around inside it. The Champion throws so much oil at the top end that they will tend to get some in the breather that goes to the air filter housing and saturate the bottom of the air filter element. Which is not a bad problem to have, really because it never plugs it so it can't breathe and the upper end is never lacking for oil on those.

    I will venture that the Champion will outlast the Generac 2:1. I have a friend up in Ontario that has had a Champion generator for several years and I don't even know how many hours he has on it now. But it's a lot and it just keeps on running and never breaks. And he hasn't been exceedingly nice to it either - leaving it set outside at 30 below then doing stuff like preheating it with a flame-thrower of some sort to get it started, and melting the voltmeter off the side of it.
    --
    Chris
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Choosing a good generator

    I solved the winder genny strt issue by simply unplugging the genny and then I store it in the heated building. Easy to do with the little EUs, a bit harder with larger gennies. With a tight fuel cap, there is no smell of fuel in house.

    Tony
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Choosing a good generator
    icarus wrote: »
    I solved the winter genny start issue by simply unplugging the genny and then I store it in the heated building.

    I also keep my generator in a warm place. That solves the problem with cold starts.

    It does NOT solve the problem of cold running :cry: When it runs, it is outdoors under a shed roof. I often need to run it in subfreezing conditions.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Choosing a good generator
    ChrisOlson wrote: »
    I will venture that the Champion will outlast the Generac 2:1. I have a friend up in Ontario that has had a Champion generator for several years and I don't even know how many hours he has on it now. But it's a lot and it just keeps on running and never breaks. And he hasn't been exceedingly nice to it either - leaving it set outside at 30 below then doing stuff like preheating it with a flame-thrower of some sort to get it started, and melting the voltmeter off the side of it.

    My Champion doesn't have an electric start, so I cannot auto-start it. If my Generac doesn't last long enough, I have an idea to get a decent quality gasoline generator and convert it to natural gas. I was also thinking about having two generators for winter use when my solar is very weak - big and small, but it's not clear to me yet if that would work better.
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator

    Wow, I go "offline" for a few days and come back to reams of great information. Thanks again ChrisOlson! and some great back and forth. I should visit this forum more often :D
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator
    BB. wrote: »
    In general, the new/modern switch mode power supplies are pretty tolerent of variable power. Many modern Power Factor Corrected (PFC) power supplies will run from ~95 to 264 VAC ~45-66 Hz (sometimes up to 400 Hz), and even DC in that range.
    Hi Bill, Just re-read your post and ironically just have an offgrid customer who's modem died around the time he was finishing equalizing his batteries with his Kubota(http://www.unitedgenerator.com/proddetail.php?prod=GL7000-USA), (Of course, he suspects the generator)! Thanks again, reminds me to check said power supply and modem when I can get back on site, though it does make me wonder if a modem could be subjected to a "mini spike" when a generator of this kind goes from heavy to no load?
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator

    Sorry, that last part might be a bit off-topic. Tried to delete it but was unable. Apologies to Chris. To try and get things back on topic I would ask then what kinds of alternators could cause damaging power irregularities when going into say 75% load, during and then out of that load and therefore be unsuitable? An example could be a large motor that could cycle(ie centrifugal booster pump) instead of the battery charging situation mentioned above.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Choosing a good generator
    To try and get things back on topic I would ask then what kinds of alternators could cause damaging power irregularities when going into say 75% load, during and then out of that load and therefore be unsuitable?

    Any of them can. When a generator is under load the voltage regulation system (either capacitor or AVR) has the flux in the rotor at a high level and the engine's governor is in a mild amount of "droop" with the engine under load. Suddenly remove that load and the the voltage will instantly go thru the roof, and the frequency will hit a high value before the engine's governor reacts.

    The deciding factor on how stable the output is depends on both the generator's voltage regulation system and how fast the controls are that regulate engine speed.

    Inverters are WAAAY faster than generators on regulating voltage and frequency. So if you're feeding an inverter with a generator and it is suddenly unloaded and goes out of spec, a good inverter is going to drop the generator like a hot potato before a damaging voltage or frequency spike can hit the equipment.
    --
    Chris
  • DavidinNica
    DavidinNica Registered Users Posts: 14 ✭✭✭
    Re: Choosing a good generator

    Good to know Chris, thanks and something worth testing. I haven't seen this specific situation happen before first hand but I have seen how fast inverters can be to act on faults before even a breaker can react.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Choosing a good generator

    I've just ordered a Subaru/Robin/Hatz 3.3KW diesel genset. Dealer claims they are discontinuing the 3.3's and keeping only the 5Kw for the small diesel gensets. But the parts department wants $90 for a glow plug !!

    I'm into 2 head gaskets on my listeroid, and no promise #3 won't fail me, even with a pint of Copper Coat on it.

    http://www.robinamerica.com/pfeatures.aspx?pid=61
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,