A couple months ago.. during debate on portable power generators, one
poster stated if I remeber correctly that majority of portable
generators produced modified sine wave power, compairable to quality
of power from cheap inverter ( bad for sensitive electronics)

1. Is this true? IIRC it was one poster who was stating this..

2. If this is true.. what do you look for when buying a generator
that delivers "quality" power that won't fry electronics? I have not
seen any stickers on units for sale that say they're modified sine
wave..
Thanks
(tropical storm/ hurricane season is here!)

Chuck
Mu2

You have it all wrong. Generators produce a real sine wave. However...
Inexpensive generators are usually not voltage regulated. There are two
consequences of this; they can wildly fluctuate voltage as the load changes,
and they are usually very noisy (both is waveform and sound.) Either one
can damage sensitive devices.
Six years ago we had a major wind storm that left a few hundred thousand
people without power for up to a week. I know of 5 furnaces that were burnt
out by unregulated generators, but there were thousands of unregulated
generators powering furnaces. So your odds are good, but the price for
being one of the losers is pretty high. Do you feel lucky? Personally I
prefer a good generator; they are safer, quieter, and generally use less
gas. Those are all good things that justify their price.

Opps I think I may have done a reply by email..

Ok,, do any openly state if they have closely regulated voltage?

Thanks..
Chuck

, 11 Aug 2004 21:04:10 GMT, "toller" wrote:

You have it all wrong. Generators produce a real sine wave. However...
Inexpensive generators are usually not voltage regulated. There are two
consequences of this; they can wildly fluctuate voltage as the load changes,
and they are usually very noisy (both is waveform and sound.) Either one
can damage sensitive devices.
Six years ago we had a major wind storm that left a few hundred thousand
people without power for up to a week. I know of 5 furnaces that were burnt
out by unregulated generators, but there were thousands of unregulated
generators powering furnaces. So your odds are good, but the price for
being one of the losers is pretty high. Do you feel lucky? Personally I
prefer a good generator; they are safer, quieter, and generally use less
gas. Those are all good things that justify their price.

Most anything under 700 is unregulated, you have to research and ask
about allot of things , what brand are you looking at.

Ok,, do any openly state if they have closely regulated voltage?

If they have voltage regulation (or possibly automatic voltage regulation)
they will feature it in their advertising copy, as it is an important and
expensive feature. If they don't mention it, they don't have it.
Sadly, it will probably cost twice as much as an unregulated genny, but you
get other good features as well; such as low noise, etc.
If price is a problem, you might get lucky with a used one. Last year I
bought a small used regulated Kawasaki with only 20 hours on it for $350; it
was about $1,000 new, but apparently the market for used Kawasakis is not
good. (Or you might get one with 1000 hours without an oil change; you have
to be careful.)

One thing not to do is let the gen run out of gas connected to anything
with Capacitors, they easilt fry. Motors, electronics etc.

On Thu, 12 Aug 2004 03:22:11 GMT, toller wrote:

Ok,, do any openly state if they have closely regulated voltage?

If they have voltage regulation (or possibly automatic voltage regulation)
they will feature it in their advertising copy, as it is an important and
expensive feature. If they don't mention it, they don't have it.
Sadly, it will probably cost twice as much as an unregulated genny, but you
get other good features as well; such as low noise, etc.
If price is a problem, you might get lucky with a used one. Last year I
bought a small used regulated Kawasaki with only 20 hours on it for $350; it
was about $1,000 new, but apparently the market for used Kawasakis is not
good. (Or you might get one with 1000 hours without an oil change; you have
to be careful.)

You might be able to get a deal on new ones, too. Around
here in Upstate NY, Home Depot has been selling the Generac
7550EXL for about $1K. Seems to be a decent generator - voltage
regulated, has an idle setting that substantially reduces
noise, electric start, pressured oiling, etc. Only other
thing I'd wish for is an oil filter.

- Rich

The Generac EXL line all have oil filters. EXL is Electric start
Extended Life. The 4000EXL the 7500 EXL and the one you mentioned 7550
EXL, They also come with an extra oil filter , Battery and float charger
and cover. I have a 7500 EXL from Lowes which often has a Transfer
Panel kit giveaway. The models on EXL are similar but Generac badges
each stores unit as unique so they dont have to expose the store to
price wars. So ineffect HD and Lowes carry the same unit plus or minus
a few features but HD will not match a price at Lowes saying it is a
different model when in actuality it is but say a 50 watt higher rating
and different color and extra extension cord, or other giveaway. The
700$ 4000 EXL is nice as is the 7500 EXL which I paid 1250 but got allot
of freebees, Air - Oil filters, plugs, Oil, Charger, and a completly
wired transfer panel , Wire- cable, Plugs , and ccver. Generac makes
their own steel sleeve, pressurised , oil filtered , electric start
motor and is owned by Briggs & Stratton.
Remember to run it with a mild load of 220 in no longer than 6 mo
intervals or the Gen Head can loose residual field magnitism and need
complicated " Flashing " to Re -magnitise the Gen Head magnetic field.

Unregulated voltage gens start at a high voltage and usualy reach 120
60 hz at load. Start voltage is usualy around 135, but cheap low powered
units easily swing 35 v ++. Even Coleman in their manual says if
electronics are to be used buy a separate regulator and they even give
you a telephone #.
Those regulators can double cheap generators cost. Regulated units
usualy swing only 10- 15v.
Honda has a line of " clean power" stable signwave generators that are
as clean or cleaner than your utility co. And they have a line that is
voltage regulated. And are very quiet in sound noise.
Whatever you get test it before you need it to full load with a meter
to be sure it will do what you need. You should look for voltage
regulation and find out the % volt swing the unit is desiged for and see
if your equipment can handle it. HZ varies with voltage , many motors
wont start if Hz is off. Look for a good motor with steel sleeve and
pressure oiled. The cheapest unit that does this is a Generac 4000exl
for 700 at HD it also has electric start and an oil filter, but it stil
swings apx 10v. For better go Honda , their inverter line is the best
but at 2.5 x the price of Generac. Some Colemans use techumpsee motors
some models which only last 350 hrs Pressure oiled steel sleeve can go
3500 hrs.
With generators you really get what you pay for

Inverters produce non sinewave output with many harmonics that are bad. The
good onces will filter much of that out, better ones can eliminate most of
it.

Generators produce sinewave output but as metioned are poorly regulated at
the low end.

Another problem is surge current. Depending on what you are powering you
will awnt to size the generator for any start current requirements for
inductive loads, otherwise the startup voltage drop you will encounter if
such a condition happens can shorten and/or burn up a motor.

Probably more exsessive than most will need, but I have a good 12000 output
Gen to handle all the fridge/freezers and small motor loads and if careful I
can even run the AC. I also feed into a good size UPS to regulate and
further protect all my elcetronics and computers in the home office. Most
electronics like a clean power on and power off, when using a generator one
can have a condition sometimes when power will come up slower and if the
generator is shutoff will cause the voltage to slowly drop, this can be bad.
Best to have a auto disconnect that will only allow output when the
generator is ready to produce full output and disconnect cleanly if the
voltage drops to a preset minimum for a specifc amount of time.



"m Ransley" wrote in message
...
Unregulated voltage gens start at a high voltage and usualy reach 120
60 hz at load. Start voltage is usualy around 135, but cheap low powered
units easily swing 35 v ++. Even Coleman in their manual says if
electronics are to be used buy a separate regulator and they even give
you a telephone #.
Those regulators can double cheap generators cost. Regulated units
usualy swing only 10- 15v.
Honda has a line of " clean power" stable signwave generators that are
as clean or cleaner than your utility co. And they have a line that is
voltage regulated. And are very quiet in sound noise.
Whatever you get test it before you need it to full load with a meter
to be sure it will do what you need. You should look for voltage
regulation and find out the % volt swing the unit is desiged for and see
if your equipment can handle it. HZ varies with voltage , many motors
wont start if Hz is off. Look for a good motor with steel sleeve and
pressure oiled. The cheapest unit that does this is a Generac 4000exl
for 700 at HD it also has electric start and an oil filter, but it stil
swings apx 10v. For better go Honda , their inverter line is the best
but at 2.5 x the price of Generac. Some Colemans use techumpsee motors
some models which only last 350 hrs Pressure oiled steel sleeve can go
3500 hrs.
With generators you really get what you pay for