Capacitor in the fluorescent light ?

[mowhoong]

What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor would definitely caused
more maintenance work to be done .
Can any members advice on this topic .

Thanks and Regards

 

[Jasen Betts]

On 2011-05-11, mowhoong <mowhoong@hotmail.com> wrote:

What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor would definitely caused
more maintenance work to be done .
Can any members advice on this topic .

The capacitor is for power factor correction,
It is not required for correct or safe operation of the light.
There may be a legal or contractual requirement for it to be present.

http://en.wikipedia.org/wiki/Power_factor#Non-linear_loads

--
⚂⚃ 100% natural

 

[whit3rd]

On Wednesday, May 11, 2011 6:10:00 AM UTC-7, mowhoong wrote:

What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor...

If the capacitor is across the AC line, it's likely to limit
radio interference. If the capacitor is on the DC side
of a rectifier, it would keep the light from flickering.
And, of course, there's LOTS of other ways a capacitor could
be part of a fluorescent lamp circuit, like DC blocking
(to prevent erosion of the lamp's filament).

 

[Phil Allison]

"Jasen Betts" <jasen@xnet.co.nz>

** Baaaaaaahhhhhhhhhh...

Google sheep alert !!!

The capacitor is for power factor correction,
It is not required for correct or safe operation of the light.
There may be a legal or contractual requirement for it to be present.

http://en.wikipedia.org/wiki/Power_factor#Non-linear_loads

** The link is not relevant or helpful.

Very misleading, actually.



..... Phil

 

[tuinkabouter]

Op 5/11/2011 9:07 PM, whit3rd schreef:

On Wednesday, May 11, 2011 6:10:00 AM UTC-7, mowhoong wrote:
What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor...

If the capacitor is across the AC line, it's likely to limit
radio interference. If the capacitor is on the DC side
of a rectifier, it would keep the light from flickering.
And, of course, there's LOTS of other ways a capacitor could
be part of a fluorescent lamp circuit, like DC blocking
(to prevent erosion of the lamp's filament).

Cos phi corrcction.

--
pim.

 

[Grant]

On Thu, 12 May 2011 15:44:37 +0200, tuinkabouter <dachthetniet@net.invalid> wrote:

Op 5/11/2011 9:07 PM, whit3rd schreef:
On Wednesday, May 11, 2011 6:10:00 AM UTC-7, mowhoong wrote:
What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor...

If the capacitor is across the AC line, it's likely to limit
radio interference. If the capacitor is on the DC side
of a rectifier, it would keep the light from flickering.
And, of course, there's LOTS of other ways a capacitor could
be part of a fluorescent lamp circuit, like DC blocking
(to prevent erosion of the lamp's filament).

Cos phi corrcction.

Power factor correction for mere mortals ;^)

I'd be a bit worried about that oil, may contain nasty PCB (?) poison if
it's an old fitting, 'cos they stopped using oil-filled caps in that
function decades ago. These days a polycarbonate cap would be placed in
there, across the line (X rated cap).

There's no DC side to a 40W fluorescent lamp circuits I've seen, did
manufacturers ever care about the lamp's filament? But maybe in AU
with 240V mains we have a different common circuit for the old fluoros?

It is common to see one side of the tube to go black, I had a 15W
desklamp put so much DC through the tube the ballast burned the bench
top black, where the lamp was used.

Grant.

 

[mowhoong]

On May 12, 5:13 pm, Grant <o...@grrr.id.au> wrote:

On Thu, 12 May 2011 15:44:37 +0200, tuinkabouter <dachthetn...@net.invalid> wrote:
Op 5/11/2011 9:07 PM, whit3rd schreef:
On Wednesday, May 11, 2011 6:10:00 AM UTC-7, mowhoong wrote:
What is the main purpose of a ac capacitor in a 40 w fluorescent
light ?
I removed a faulty capacitor and still the fluorescent light is on. It
seems that oil leak from the faulty capacitor...

If the capacitor is across the AC line, it's likely to limit
radio interference.  If the capacitor is on the DC side
of a rectifier, it would keep the light from flickering.
And, of course, there's LOTS of other ways a capacitor could
be part of a fluorescent lamp circuit, like DC blocking
(to prevent erosion of the lamp's filament).

Cos phi corrcction.

Power factor correction for mere mortals ;^)

I'd be a bit worried about that oil, may contain nasty PCB (?) poison if
it's an old fitting, 'cos they stopped using oil-filled caps in that
function decades ago.  These days a polycarbonate cap would be placed in
there, across the line (X rated cap).

There's no DC side to a 40W fluorescent lamp circuits I've seen, did
manufacturers ever care about the lamp's filament?  But maybe in AU
with 240V mains we have a different common circuit for the old fluoros?

It is common to see one side of the tube to go black, I had a 15W
desklamp put so much DC through the tube the ballast burned the bench
top black, where the lamp was used.

Grant.- Hide quoted text -

- Show quoted text -

Thanks to all members for the response