OT: They shouldn't be shops like these!

On Sat, 18 Mar 2006 12:07:21 GMT, Derek wrote:

> Dave I've seen those 3KVA I was weakening toward the 'rebuild it
> yourself £50' option ...

If I knew what the engines were and the availabilty/cost of spares for
them I'd be tempted to go that route as well.

> ... what does that output come down to on a 230v.

I don't understand the question.

> god know what I need it for tho'.

Back up for when the mains power goes off or camping/remote BBQ party
WHY. Considering where we live (high on the North Pennines overhead lines
all the way from the grid) our power is very reliable but cuts come in
two forms. A quick off/on as the auto-reclosure does its stuff on a
temporary fault/overload or three quick off/on cycles then nothing for at
least 6hrs.

--
Cheers [email protected]
Dave. pam is missing e-mail

"Dave Liquorice" <[email protected]> wrote in message
news:[email protected]...
On Sat, 18 Mar 2006 12:07:21 GMT, Derek wrote:

> Dave I've seen those 3KVA I was weakening toward the 'rebuild it
> yourself £50' option ...

If I knew what the engines were and the availabilty/cost of spares for
them I'd be tempted to go that route as well.

> ... what does that output come down to on a 230v.

I don't understand the question.

> god know what I need it for tho'.

Back up for when the mains power goes off or camping/remote BBQ party
WHY. Considering where we live (high on the North Pennines overhead lines
all the way from the grid) our power is very reliable but cuts come in
two forms. A quick off/on as the auto-reclosure does its stuff on a
temporary fault/overload or three quick off/on cycles then nothing for at
least 6hrs.

--
Cheers [email protected]
Dave. pam is missing e-mail

You've convinced me Dave I'll show Vicky your response it's a sound argument
she is a born barbequer- they wean them on BBQ ribs and chicken in Michigan
all I need is the space in the garage once I rewire the bigger compressor I
can sell to 25litre and the bath will be going in any
time.......................... this may take a little time. Here in
Timperley we rarely get cuts benefit of being near to a major airport and a
large city ,the traffic jams are a bonus.
What I was asking about the output as its around 35years since I did physics
running 230v what wattage would we be looking at ( I dont even remember
Flemings left hand rule to be honest) does it work VA is the voltage x
amperage, so 230V x13A= 3kVA or that works as 3kw output really I should
know but its not something I have ever had to calculate aside from working
out fuse rates
Derek

Dave Liquorice wrote:

> On Sat, 18 Mar 2006 12:07:21 GMT, Derek wrote:
>
>> Dave I've seen those 3KVA I was weakening toward the 'rebuild it
>> yourself £50' option ...
>
> If I knew what the engines were and the availabilty/cost of spares for
> them I'd be tempted to go that route as well.
>

IIRC the Onan gensets were made by Cummins, so spares shouldn't be too
difficult. Cost OTOH...

P.

....and Paul S. Brown spake unto the tribes of Usenet, saying...

> IIRC the Onan gensets

Built by merchant bankers, for merchant bankers.

>were made by Cummins,

<snort>

<hat, coat, gone.>

--
Rich
==============================

There are 10 kinds of people in the world - those who understand binary
and those who don't.

On Sat, 18 Mar 2006 15:52:50 GMT, Derek wrote:

> ... does it work VA is the voltage x amperage, so 230V x13A= 3kVA or
> that works as 3kw output

More or less, got to admit I'm hazy about the difference between the kVA
and kW rating of generators. I think the kVA rating is the better measure
as, I think again, it takes into account the phase angle, thus is more
indicative of the true power available. In broad terms the kVA rating is
normally about 80% of the kW one.

Maybe some one will come along an enlighten the two of us?

--
Cheers [email protected]
Dave. pam is missing e-mail

Dave Liquorice wrote:
> On Sat, 18 Mar 2006 15:52:50 GMT, Derek wrote:
>
>> ... does it work VA is the voltage x amperage, so 230V x13A= 3kVA or
>> that works as 3kw output
>
> More or less, got to admit I'm hazy about the difference between the kVA
> and kW rating of generators. I think the kVA rating is the better measure
> as, I think again, it takes into account the phase angle, thus is more
> indicative of the true power available. In broad terms the kVA rating is
> normally about 80% of the kW one.

I don't thjink this is easy to explain, but here goes.

kW are what is delivered as real power to your load. WHAT is delivered
depends on your actual electrical load. A resisitive load like a heater
of 24Ohms resistance will consume say 10Amps at 240V and will obviously
"burn" 240 x 10 amps , or 2400 Watts. The voltage changes and the
current changes IN PHASE, so if you draw a graph of current through the
load (a nice sine wave) and a graph of voltage acrosss the load (another
nice sine wave), then the two graphs will lie exactly on top of each other.

Now, if you have what we call a "reactive load", like an induction
motor, or a bloody BIG pile of fluorescent lights it WILL NOT draw
current in phase with the voltage, and yor pretty graph will show a nice
sine wave of current, and a nice sine wave of voltage NOT in phase - in
the worst case, the current graph will be at a maximum when the volts
are at zero and vice versa, essentially now, since power = current X
volts ZERO real power is consumed - NO heat is generated !

Unfortunately though, your genny still has to supply the maximum voltas
and the maximum current as if it still fed the purely resistive load, so
if your reactive load showed 240 V and 10 A on its meters, even if its
out of phase, your genny is still supplying 240 X 10 *VA* This is why
they are rated in (k)VA not in (k)W

Technically now, the cosine of the phase angle between the current and
voltage waves is called the Power factor, and Power = Power factor X
Volts X current. In a pure heating load power factor = 1, in a purely
reactive load it equals 0. A typical motor load will have a power factor
of roughly 0.6..0.8

You will find an electricity supplier is VERY unhappy if you feed a
highly reactive load with their service, because though you are taking
nothing they can bill you for, their wires are still feeding volts and
current.

HTH

Steve

Richard Brookman wrote:
> ...and Paul S. Brown spake unto the tribes of Usenet, saying...
>
>> IIRC the Onan gensets
>
> Built by merchant bankers, for merchant bankers.
>
>> were made by Cummins,
>
> <snort>
>
> <hat, coat, gone.>
>
Dorothy Parker had a budgie called Onan - because it spilled its seed.....

Steve

Steve Taylor wrote:

> You will find an electricity supplier is VERY unhappy if you feed a
> highly reactive load with their service, because though you are taking
> nothing they can bill you for, their wires are still feeding volts and
> current.
>

Ah yes - the good old "Power Factor Correction" gimmick.

/me goes to buy some *big* capacitors....

P.

Paul S. Brown wrote:

> /me goes to buy some *big* capacitors....

Modern electronic meters aren't "phased" by that at all - you get billed
for VA.

Steve

Steve Taylor wrote:

> Paul S. Brown wrote:
>
>> /me goes to buy some *big* capacitors....
>
> Modern electronic meters aren't "phased" by that at all - you get billed
> for VA.
>

Got a big spinning thing with "Ferranti" written on it here - I suspect that
may just get its knickers in a twist

P.

....and Steve Taylor spake unto the tribes of Usenet, saying...


> Richard Brookman wrote:
>> ...and Paul S. Brown spake unto the tribes of Usenet, saying...
>>
>>> IIRC the Onan gensets
>>
>> Built by merchant bankers, for merchant bankers.
>>
>>> were made by Cummins,
>>
>> <snort>
>>
>> <hat, coat, gone.>
>>
> Dorothy Parker had a budgie called Onan - because it spilled its
> seed.....
> Steve

Remind me to tell you the joke about a dog called "Tosser" when we next meet
up...

--
Rich
==============================

There are 10 kinds of people in the world - those who understand binary
and those who don't.

"Steve Taylor" <[email protected]> wrote in message
news:[email protected]...
> Richard Brookman wrote:
>> ...and Paul S. Brown spake unto the tribes of Usenet, saying...
>>
>>> IIRC the Onan gensets
>>
>> Built by merchant bankers, for merchant bankers.
>>
>>> were made by Cummins,
>>
>> <snort>
>>
>> <hat, coat, gone.>
>>
> Dorothy Parker had a budgie called Onan - because it spilled its seed.....
>
> Steve
Reminds me I have a computer game ( nothing to do with barbarians) featuring
a movie clip(s) on the subject as a reward for completeing the game.
Derek
<smiles>

On or around Sat, 18 Mar 2006 22:38:56 +0000, Steve Taylor
<[email protected]> enlightened us thusly:

>Now, if you have what we call a "reactive load", like an induction
>motor, or a bloody BIG pile of fluorescent lights it WILL NOT draw
>current in phase with the voltage, and yor pretty graph will show a nice
>sine wave of current, and a nice sine wave of voltage NOT in phase - in
>the worst case, the current graph will be at a maximum when the volts
>are at zero and vice versa, essentially now, since power = current X
>volts ZERO real power is consumed - NO heat is generated !

of course, if said item is not consuming any power, it's not gonna do any
work... do there's something wrong with the theory.
--
Austin Shackles. www.ddol-las.net my opinions are just that
"My centre is giving way, my right is in retreat; situation excellent.
I shall attack. - Marshal Foch (1851 - 1929)

Austin Shackles wrote:

> of course, if said item is not consuming any power, it's not gonna do any
> work... do there's something wrong with the theory.

AFAIR Power factor for an AC motor does tend to 1 as you mechanically
load it.

Power systems are funny beasts - its amazing that a whole plant can be
set to feed only VA into the grid- running like buggery for zero power out !

Steve