Power generator system.

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OK, looks like Sydney will suffer some blackouts this coming Summer. I
figure I need to start looking for a suitable generator. I figure I'll limit
myself to 4 stroke engines, for reasons of noise, maintenance, pollution and
fuel economy. The trick, I guess is to work out how big a device I need.
1kVA should be adequate to run the workshop and a TV or two. How big will I
need to go to run the 'fridge as well? Maybe the microwave. I guess the
microwave won't require substantial start-up capacity, but the 'fridge will.
How well can generators cope with motor start-ups? Any thoughts, experiences
and suggestions will be welcome.


--
Trevor Wilson
www.rageaudio.com.au



Re: Power generator system.



"Trevor Wilson"
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 **  A 1 kVA gene is incredibly small ( also very noisy) -  would only have
a lawn mower engine driving it.

The problem for electronic equipment use is making sure you get a steady 240
volt, 50 Hz output   -   small genes regulate the voltage by varying the
speed of their motor !!

A 5 kVA or larger unit with silencing and proper frequency control is the
o  - but far from cheap.



...........    Phil






Re: Power generator system.


On Mon, 18 Jul 2005 13:31:39 +1000, "Phil Allison"

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I bought one of those cheap 750w jobs from Bunnings. ITs main purpose
was to run 1 500w halogen. Its not the quietest, but its definately
not the loudest either. Does the job and will also run a decent size
fridge/freezer during the day when you go camping!!

If you are looking for a very quiet and reliable generator, take a
trip to your local honda dealer. They have a series of little red
portable units ranging (from memory) 900w upto about 3kw. They are 4
stroke, inverter models and are extremely quiet. Get your local dealer
to fire one up, i guarentee you will be surprised. The slightly larger
honda's are just as quiet and i think they go up to about 5kva.

We use one of the 1.1kva units for camping, usually runs for about
14hours straight - running a radio, two large bar fridges and 2-3
40watt bulbs. We leave it running around the clock, and only stop it
to top up the oil each morning.

I have also seen QLD trade tools selling a cheaper honda look alike
model, which is also 4 stroke. I have been meaning to check them out
but have not had a chance.

Regards:

Andy.



BTW, you will be surprised at how big a fridge those little generators
can drive. My 750W unit easily runs my 250l Kelvinator beer fridge!!


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Model number?

was it 4 stroke?

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    Phil is right about frequency control: some fridge compressors
will burn out if the frequency is off by say 5 Hz or more. Also a
rewinder I know makes his "bread and butter" money by rewinding
alternators that have sat all year absorbing moisture in the shed
and promptly arc out when they are fired up with no load across the
output. So you'll have to store it in a dry environment (airconditioned
room) which has a low moisture content and run it from time to time
with a load to heat up the windings and dry them out.

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Would a large sealed garbage bag containing a few silica sachets combat
this?
Still fire it up from time to time, but would it live if you forget to run
it for 6 months?

-mark



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  I'd say it would have to help, though a thicker plastic bag would be
less permeable. The more preventaive maintenance you take the better.
It's all relative: I've seen 5KVA Dunlites stored in waterfront sheds
with salt crystals on the windings after a couple of years storage. The
more they get used the longer they last. A prawn trawler alternator
hardly ever stops and they go for years as they are always warm and dry
from use.

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Might be a bit difficult to start, but assuming you left  pistons in
the compression phase it should be fine



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limit
and
I
will.
experiences
Look at small marine generators. They are quiet and cheap yet robust. Sizing
is another issue of course but the range should satisfy.

Ken



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If you have access to natural gas you might look at a gas fired
generator. They are less noisy and cleaner to run.

Re: Power generator system.


On Mon, 18 Jul 2005 03:18:19 GMT, "Trevor Wilson"

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Trevor,

The small Bunnings $99 750W guys will run a small TV, but don't have
the surge current ability to start a normal household fridge/freezer.
They can just run a 2 HP circular saw, but with far reduced
performance over the normal mains supply. These little generators
aren't exactly quiet, not like the well-silenced Honda units. Otoh
thay sure don't cost as much as the Honda's! :)

I think when I searched the web on this subject you need at least 3KVA
to start normal household fridge/freezers.

I bought some 12V battery to 240V inverters, and even the smallest of
these  these will run a TV but put lines on the screen because of the
square wave output voltage.

Using a normal car battery with an inverter then they don't like the
constant deep discharge/charge cycle if you are using the inverter
regularly, and car batteries will apparently fail fairly quickly with
this duty. However, this wouldn't be an issue for the occasional
sporadic power failure and limited use.

I have everything from Kero hurricane lamps to LPG
lights/heaters/stoves to motor-generators to inverters. I'd use LPG
and kerosene for lights. Use a small 12V B+W $20 TV to watch the news.
The motor-generator for a drill or small test gear in the workshop,
and the inverter for the laptop!

While I've been all prepared for power fails for yonks the power
actually hasn't failed at an inconvenient time, but it is all good
stuff for camping. :)

Ross
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(To get email address ROT 13)
ebff snipped-for-privacy@lnubb.pbz

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I disagree regarding the fridge/freezer. In my experience, this unit
will run a reasonable sized domestic fridge OR freezer but not both -
the breaker trips out if both are attempted.

I have run all my computer gear ie computer, CRT Monitor, printer,
router, modem off this unit with no problems but I did run a 150W
halogen light as well just to provide a decent load else the voltage
starting going over 250V.

HTH

Dave Goldfinch

Re: Power generator system.


Trevor,

Why will Sydney get blackouts?



Re: Power generator system.



"Heywood Jablome" <reply to thread> wrote in message
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**Our base load capacity will probably be exceeded this Summer. If not this
Summer, then definitely next Summer. Sydney's population is growing and
there has been no spending in base load capacity for many years. The failure
of one coal fired generator, at an inconvenient time, will cause major
problems. Apparently the infrastructure is past its use-by date and we have
been real lucky so far. It will only get worse over the next few years,
until some serious money is spent on generators. I guess the most telling
comment came from Bob Carr when he mentioned Nuclear power generation. I
believe he is softening the public up. They're objecting now, but when our
power is cut for a few days, we'll be prepared to generate power from
burning newborn babies, if necessary. Nuclear power will appear to be a
great idea.

For my own interests, I lived through a 2 day blackout a few years ago. It
cost me two days work. More than enough to justify the purchase of a modest
sized generator. If the blackouts do eventuate I want to be well prepared.
The workshop is most important, the food, less so.

Thanks to all who have replied. The information has been most informative.
Looks like a large(ish) generator is the way to go. I certainly want to
maintain 50Hz.


--
Trevor Wilson
www.rageaudio.com.au



Re: Power generator system.



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this
failure
have
modest

Oh ok. I hear Victoria's gas and electricity systems are under pressure (no
pun intended) as well. I wonder whether during an extended power outage if
the internet goes down as well. I guess telephone lines have good battery
standby circuits as well as generators no doubt, so adsl would be ok as long
as the servers are backed up as well.

I'm having internet withdrawal symptoms just thinking about it.



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Re: Power generator system.



"Heywood Jablome" <reply to thread> wrote in message
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**I don't think you need worry. I worked for OTC (Overseas
Telecommunications Commission), many years ago. OTC was absorbed by Telstra.
ALL OTC stations had significant backup systems. The ones in the Broadway
exchange were amazing (at the time - early 1970s). A huge room full of
'submarine' lead acid cells. Huge Pyrex glass batteries. Incredibly
expensive. (OTC was a seriously well cashed up. Money was never a problem.)
This provided the 48 Volt DC, from which every piece of equipment operated.
The batteries could keep the entire building operational for about 30
minutes. Plenty of time to start up the two, huge diesel generators (only
one of which was sufficient to power the whole place). A similar setup was
in existence at Paddington exchange. Ditto, Doonside and Bringelly (HF
transmission and reception). I am certain that every Telstra exchange has
the same kind of backup systems in place.


--
Trevor Wilson
www.rageaudio.com.au



Re: Power generator system.



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Well Yes and no the Trend nowadays (especially after a couple of embarassing
incidents (North Sydney, Haymarket) where Batteries had not been
Cycled/Maintained properly following Telstra's Cost cutting exercises ... I
digress) is for Smaller distibuted battery banks/Rectifier sets to be
distributed around the exchanges, however the Battery Banks are really only
intended to last long enough (with a safety margin) for the Generator to
kick in.



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A few Years ago - prob 6? after the Storms I ended up running a 5KVA Honda
Genny I borrowed off my boss for several days (off and on mainly during the
day to keep the fridge running) until we got the power Back. It was not
quiet however it was not to loud either and we hid it in the Garden shed
which baffled a lot of the Sound.
My wife even ran the Dryer off it as well as the Fridge etc and we supplied
my parents place next door.
Of course at 5KVA it did not skip a beat and Fuel consumption was not as bad
as I expected.

oh hang on I was going to ask why you think we will have more blackouts than
usual this summer ?

Regards
Richard Freeman



Re: Power generator system.


On Tue, 19 Jul 2005 13:42:09 +1000, "Richard Freeman"

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A problem with 1 kva units is that they tend to be plasticy noisy and
a bit shoddy. We have some in our SES unit, but we basically NEVER use
em, primarily coz we normally run 1500 watt lights though.

The generators we use tend to be 3.5kva, 5kva an 9kva models with
-earth stake
-rcd
and I think, sieze protection.

YOu should look at getting a generator with all of the above, and
similarly sized, since it will be of better quality, allow start up
surges and weird power factors, and prevent bad damage if oil runs
out.
They are 2 stroke, and are a bit noisy, but it isnt really a problem
if you run thm away from the house like you are supposed to.

Also If you're getting a generator, pick up a dry chemical or co2
fire extinguisher to use with it.
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-really dangerous mate. Its a fire hazard, and a suffocation hazard
when you go in there to refuel/turn it off.

Running a generator in a confined space is a big no-no
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Running a diesel generator at too low a load (generally considered to be
about 30% of rating) can lead to coking and/or damage to the genset. Not
sure of petrol gen's, but if you intend to run this continuously for days on
end then diesel is a better option (ratings notwithstanding).

Ken



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