Posted by ransley on June 22, 2010, 11:43 am
> > I picked one of these up at Lowes to temporarily power some incandescent
> > lights. With a couple of hundred watts of load I notice that the lights
> > flicker slightly but annoyingly. For a normal generator I'd let it slide,
> > but I thought the point of these inverter designs was "clean" power. Is
> > slight flickering typical of the iX2000 or did I get a bad one?
> > Dan Lanciani
> > ddl@danlan.*com
> Dan,
> Why does a generator need an inverter at all? Doesn't it put out pure
> sinewave A/C to begin with?
> I would <groan> call Generac to see what they say (their web site was pretty
> silent about the inverter technology) but refuse a rebuilt, who knows what
> happened to it, unit and return the item to the store where hopefully you
> can either try a new one of the same model (which they will probably gladly
> do since it means you weren't trying to scam them by using it as a free
> rental) or get your money back and try another brand.
> What a pain, though. I suspect that you'd need something like the big
> toroidal transformers made by Sola we used to use in the color darkroom to
> keep the enlarger lamps at precisely the right color temperature. I still
> see those types of transformers (huge - about 18" in diameter and 12" deep)
> on This Old House when they are doing high end AV installs. You would think
> modern microprocessor technology could compensate for rotation and load
> variations enough to "smooth out" the output so it wouldn't cause
> flickering. I would be interested to see what happens if you add more
> lights.
> Have you tried CFL lamps instead of the incandescents or mixed in with them?
> It could be that their internal electronics will overcome the flickering.
> Hey, stranger things have happend!
> Besides, in a few years, the Greenie Police will confiscate your illegal
> tunsten filament bulbs and fine you for your inefficiency.
> --
> Bobby G.
The inverter type is a unit that varies voltage by rpm, it can run as
low as 900 rpm to power a light bulb.. Regular gens run at 3600 rpm,
its a big waste of evergy to power a small load and engine life
[depending on quality] is about 300-3000 hours, Inverter gens by honda
run with a few hundred watts are known to last 11000 hours. RPM
directly relates to engine life, this is the main reason a 1800 rpm
deisel lasts 4x as long as a 3600 gas engine, and 1100 rpm Lister
generators can go 100,000 hours, and deisel boat engines that maybe
run at 100 rpm run nearly forever. The Honda inverter also has the
Generator as part of the motor, it cuts about 30% of the weight out
making for a compact lightweight unit. So for long term low load at a
remote site such as a cabin, if the load is kept to a minimum you can
with an Inverter get 9-12000 hours life vs 3-350 for the cheap non OHV
B&S engine. Inverters 2.5x premium in cost can be worth it for someone
living for example on a boat or camper for long periods. Plus Hondas
inverters have cleaner power than your power co and are so quiet you
cant hear them from 10 ft away. Generac probably stole the design but
his batch looks to be infected with a defective part. I would not
exchange it for a unit of the same batch. Once I got a cheap Generac
power washer, it blew in 2 hrs, the replacement lasted 1 hr, it was
the same batch and had the same defect. Inverter technology is great,
but there are a few others on the market that have proven reliability
like Yamaha
Posted by Robert Green on June 23, 2010, 4:45 am
news:9c85dff8-f40f-4bf5-a2b9-
<stuff snipped>
<The inverter type is a unit that varies voltage by rpm, it can run as
low as 900 rpm to power a light bulb.. Regular gens run at 3600 rpm,
its a big waste of evergy to power a small load and engine life
[depending on quality] is about 300-3000 hours, Inverter gens by honda
run with a few hundred watts are known to last 11000 hours. RPM
directly relates to engine life, this is the main reason a 1800 rpm
deisel lasts 4x as long as a 3600 gas engine, and 1100 rpm Lister
generators can go 100,000 hours, and deisel boat engines that maybe
run at 100 rpm run nearly forever. The Honda inverter also has the
Generator as part of the motor, it cuts about 30% of the weight out
making for a compact lightweight unit. So for long term low load at a
remote site such as a cabin, if the load is kept to a minimum you can
with an Inverter get 9-12000 hours life vs 3-350 for the cheap non OHV
B&S engine. Inverters 2.5x premium in cost can be worth it for someone
living for example on a boat or camper for long periods. Plus Hondas
inverters have cleaner power than your power co and are so quiet you
cant hear them from 10 ft away. Generac probably stole the design but
his batch looks to be infected with a defective part. I would not
exchange it for a unit of the same batch. Once I got a cheap Generac
power washer, it blew in 2 hrs, the replacement lasted 1 hr, it was
the same batch and had the same defect. Inverter technology is great,
but there are a few others on the market that have proven reliability
like Yamaha>
Thanks for the explanation. That Generac unit looked cute and portable
enough to use on camping trips. But since I've owned Honda cars since 1980
with great satisfaction, I think I'll see what they have to offer.
--
Bobby G.
Posted by ransley on June 23, 2010, 11:06 am
wrote:
> news:9c85dff8-f40f-4bf5-a2b9-
> <stuff snipped>
> <The inverter type is a unit that varies voltage by rpm, it can run as
> low as 900 rpm to power a light bulb.. Regular gens run at 3600 rpm,
> its a big waste of evergy to power a small load and engine life
> [depending on quality] is about 300-3000 hours, Inverter gens by honda
> run with a few hundred watts are known to last 11000 hours. RPM
> directly relates to engine life, this is the main reason a 1800 rpm
> deisel lasts 4x as long as a 3600 gas engine, and 1100 rpm Lister
> generators can go 100,000 hours, and deisel boat engines that maybe
> run at 100 rpm run nearly forever. The Honda inverter also has the
> Generator as part of the motor, it cuts about 30% of the weight out
> making for a compact lightweight unit. So for long term low load at a
> remote site such as a cabin, if the load is kept to a minimum you can
> with an Inverter get 9-12000 hours life vs 3-350 for the cheap non OHV
> B&S engine. Inverters 2.5x premium in cost can be worth it for someone
> living for example on a boat or camper for long periods. Plus Hondas
> inverters have cleaner power than your power co and are so quiet you
> cant hear them from 10 ft away. Generac probably stole the design but
> his batch looks to be infected with a defective part. I would not
> exchange it for a unit of the same batch. Once I got a cheap Generac
> power washer, it blew in 2 hrs, the replacement lasted 1 hr, it was
> the same batch and had the same defect. Inverter technology is great,
> but there are a few others on the market that have proven reliability
> like Yamaha>
> Thanks for the explanation. That Generac unit looked cute and portable
> enough to use on camping trips. But since I've owned Honda cars since 1980
> with great satisfaction, I think I'll see what they have to offer.
> --
> Bobby G.
Call a few big generator stores that you find online, they know better
than me what makes work and which ones break, HD is good for the 30
day no questions policy and the bigger 3600 rpm units. I would like a
Tri Fuel gen and just hook it to a Ng line.
Posted by Johnny B Good on June 22, 2010, 6:22 pm
> > I picked one of these up at Lowes to temporarily power some incandescent
> > lights. With a couple of hundred watts of load I notice that the lights
> > flicker slightly but annoyingly. For a normal generator I'd let it slide,
> > but I thought the point of these inverter designs was "clean" power. Is
> > slight flickering typical of the iX2000 or did I get a bad one?
> >
> > Dan Lanciani
> > ddl@danlan.*com
> Dan,
> Why does a generator need an inverter at all? Doesn't it put out pure
> sinewave A/C to begin with?
====snip====
You'd think so, wouldn't you? However, the reality is that a cheap
standby generator puts out a rather distorted waveform on load (it looks
ok without load) but this isn't the issue. The real problem with a
conventional alternator is its suceptability to overvolting with even a
modest capactive loading which becomes a problem with certain models of
UPSes that switch a large amount of capacitance across the line when
they return to pass through mode.
About two years back, I bought a cheap 2.5KVA petrol(gasoline)
generator from my local Aldi store to supplement the 2KVA APC
SmartUPS2000 that I use to provide a protected supply to my computer
kit. After much testing, it turned out that it was basically useless for
this purpose since even a modest 4.7 microfarad capacitor was sufficient
to make the generator output jump from its regulated 230v to some 275
volts.
The UPS was switching twice that amount of capacitance across the line
every time it saw the generator voltage return to normal and tried to
revert back to "mains" power which caused it to immediately switch back
to battery as the generator voltage shot back up to some 270 volts, a
process that would go on ad infinitum until I reconnected back to the
PSU power.
An inverter type of generator drives a high voltage version of a car
alternator with a permanent magnet rotor which feeds a 3 phase fullwave
bridge rectifier and capacitor smoothing pack and uses throttle control
to maintain its DC output voltage feed to the Sinewave inverter which is
immune to this capacitive loading issue.
It wasn't the 5Khz noise ripple from the cogging effect of the stator
windings, nor the gross amount of harmonic distortion, nor even the
subharmonic content due to the speed modulation effect of using a single
cylinder 4 stroke prime mover nor even the +/-5% speed/frequency
varations between no load and full load on the generator supply as I
initially had suspected, it was simply the total lack of voltage control
in the face of capacitive loading variations.
It took nearly a year before coming to this startling conclusion and
many hours of rigging up test solutions to combat the problem. One
solution I tried was to rig up a parallel inductor to cancel the
capacitive loading but this didn't entirely solve the problem.
Another solution I'm considering is to use a bunch of universal 150W
laptop chargers to create a 54v 2KW battery charger to allow the UPS
inverter to run indefinitely off its battery pack, float charged from
generator power, (in 4 or 5 banks of three wired in series to make up
the 54 volts from 3 times their 18v output setting fed from an
autotransformer set to supply them at a nominal 190vAC from the genny's
230v so that even if the genny voltage jumps up to 280v, they'll not
suffer any overvolt damage).
This, unfortunately depends upon a local fleamarket trader coming good
on his promise to be able to supply me with 15 or so such laptop
chargers at a low enough price to make it a worthwhile proposition. Even
supposing I managed to get hold of the chargers, this still leaves the
issue of uprating the ventillation on the UPS (not a difficult task ;-)
in order to allow it to run in this mode indefinitely.
TBH, I'm now on the lookout for a secondhand 3KW inverter type
generator to replace the cheap 'n' cheerful pile of crap I've currently
got. I couldn't really justify the price of a brand new unit, but it
would neatly solve all the issues at a stroke. If I'd known, when I
bought the generator, what I know today, I would have only considered an
inverter type in the first place.
Posted by Jim Wilkins on June 23, 2010, 12:50 am
wrote:
>...
Have you played with a ferroresonant Constant Voltage Transformer amid
this mish-mash? I'm curious if a UPS works with them but don't want to
risk destroying anything.
jsw
> > lights. With a couple of hundred watts of load I notice that the lights
> > flicker slightly but annoyingly. For a normal generator I'd let it slide,
> > but I thought the point of these inverter designs was "clean" power. Is
> > slight flickering typical of the iX2000 or did I get a bad one?
> > Dan Lanciani
> > ddl@danlan.*com
> Dan,
> Why does a generator need an inverter at all? Doesn't it put out pure
> sinewave A/C to begin with?
> I would <groan> call Generac to see what they say (their web site was pretty
> silent about the inverter technology) but refuse a rebuilt, who knows what
> happened to it, unit and return the item to the store where hopefully you
> can either try a new one of the same model (which they will probably gladly
> do since it means you weren't trying to scam them by using it as a free
> rental) or get your money back and try another brand.
> What a pain, though. I suspect that you'd need something like the big
> toroidal transformers made by Sola we used to use in the color darkroom to
> keep the enlarger lamps at precisely the right color temperature. I still
> see those types of transformers (huge - about 18" in diameter and 12" deep)
> on This Old House when they are doing high end AV installs. You would think
> modern microprocessor technology could compensate for rotation and load
> variations enough to "smooth out" the output so it wouldn't cause
> flickering. I would be interested to see what happens if you add more
> lights.
> Have you tried CFL lamps instead of the incandescents or mixed in with them?
> It could be that their internal electronics will overcome the flickering.
> Hey, stranger things have happend!
> Besides, in a few years, the Greenie Police will confiscate your illegal
> tunsten filament bulbs and fine you for your inefficiency.
> --
> Bobby G.