Electrical Engineering - 58 watt Fluorescent Lamps Power Requirement

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58 watt Fluorescent Lamps Power Requirement

martin

2008-03-26, 9:25 am

Please excuse the elementary question, but with
a 5 foot fluorescent light the LPF and HPF types,
(with and without a fitted power correction capacitor).

On a conventional domestic supply meter, which would
register the higher power consumption or would they
be the same.

Martin

Salmon Egg

2008-03-26, 5:25 pm

In article <47EA1805.70408@ntlworld.com>,
martin <martin.george@ntlworld.com> wrote:

> Please excuse the elementary question, but with
> a 5 foot fluorescent light the LPF and HPF types,
> (with and without a fitted power correction capacitor).
>
> On a conventional domestic supply meter, which would
> register the higher power consumption or would they
> be the same.
>
> Martin

Practically, they would both consume about the same power. The LPF (low
power factor) will cause some additional power loss to be produced
somewhere.

Bill

Andrew Gabriel

2008-03-26, 8:25 pm

In article <47EA1805.70408@ntlworld.com>,
martin <martin.george@ntlworld.com> writes:
> Please excuse the elementary question, but with
> a 5 foot fluorescent light the LPF and HPF types,
> (with and without a fitted power correction capacitor).
>
> On a conventional domestic supply meter, which would
> register the higher power consumption or would they
> be the same.

They would be the same.

LPF would draw approx twice the current though, which
you have to bear in mind when working out circuit load
and fusing, particularly when using several such fittings.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

James Sweet

2008-03-26, 9:25 pm

"martin" <martin.george@ntlworld.com> wrote in message
news:47EA1805.70408@ntlworld.com...
> Please excuse the elementary question, but with
> a 5 foot fluorescent light the LPF and HPF types,
> (with and without a fitted power correction capacitor).
>
> On a conventional domestic supply meter, which would
> register the higher power consumption or would they
> be the same.
>
> Martin
>

Depends on what the meter measures. USA residential meters measure true
power, in other words, HPF and LPF will cost you the same, although it's
always best to strive for as close to unity as possible, as it reduces waste
in the resistance of the wire. Someone told me that power meters in some
countries measure apparent power, I don't know if this is true or not, but
if it is, then HPF will cost approximately half.

Andrew Gabriel

2008-03-27, 5:25 pm

In article <mYCGj.4467$Ew5.2750@trnddc04>,
"James Sweet" <jamessweet@hotmail.com> writes:
>
> Depends on what the meter measures. USA residential meters measure true
> power, in other words, HPF and LPF will cost you the same, although it's
> always best to strive for as close to unity as possible, as it reduces waste
> in the resistance of the wire. Someone told me that power meters in some
> countries measure apparent power, I don't know if this is true or not, but
> if it is, then HPF will cost approximately half.

UK residential customers have to be metered on true power.

Power companies are allowed to use other schemes for
non-residential customers.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

phil-news-nospam@ipal.net

2008-03-28, 3:25 am

On 27 Mar 2008 19:41:31 GMT Andrew Gabriel <andrew@cucumber.demon.co.uk> wrote:
| In article <mYCGj.4467$Ew5.2750@trnddc04>,
| "James Sweet" <jamessweet@hotmail.com> writes:
|>
|> Depends on what the meter measures. USA residential meters measure true
|> power, in other words, HPF and LPF will cost you the same, although it's
|> always best to strive for as close to unity as possible, as it reduces waste
|> in the resistance of the wire. Someone told me that power meters in some
|> countries measure apparent power, I don't know if this is true or not, but
|> if it is, then HPF will cost approximately half.
|
| UK residential customers have to be metered on true power.

So you can have a power factor of 0.1 at home and not be dinged for it?

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2008-03-27-2230@ipal.net |
|------------------------------------/-------------------------------------|

krw

2008-03-28, 5:25 pm

In article <fshoqf12lv1@news5.newsguy.com>, phil-news-
nospam@ipal.net says...
> On 27 Mar 2008 19:41:31 GMT Andrew Gabriel <andrew@cucumber.demon.co.uk> wrote:
> | In article <mYCGj.4467$Ew5.2750@trnddc04>,
> | "James Sweet" <jamessweet@hotmail.com> writes:
> |>
> |> Depends on what the meter measures. USA residential meters measure true
> |> power, in other words, HPF and LPF will cost you the same, although it's
> |> always best to strive for as close to unity as possible, as it reduces waste
> |> in the resistance of the wire. Someone told me that power meters in some
> |> countries measure apparent power, I don't know if this is true or not, but
> |> if it is, then HPF will cost approximately half.
> |
> | UK residential customers have to be metered on true power.
>
> So you can have a power factor of 0.1 at home and not be dinged for it?
>
The US is the same. Watt-hour meters measure energy.

--
Keith

Andrew Gabriel

2008-03-29, 9:25 am

In article <fshoqf12lv1@news5.newsguy.com>,
phil-news-nospam@ipal.net writes:
> On 27 Mar 2008 19:41:31 GMT Andrew Gabriel <andrew@cucumber.demon.co.uk> wrote:
>|
>| UK residential customers have to be metered on true power.
>
> So you can have a power factor of 0.1 at home and not be dinged for it?

Correct.

The EU has/is imposing minimum power factors on various volume
electrical goods over certain power ratings.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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