CFLs and rental properties.

[KR]

On Apr 2, 1:21 am, "ian field" <gangprobing.al...@ntlworld.com> wrote:

"Jasen Betts" <ja...@xnet.co.nz> wrote in message

news:gqvfc8$tu6$3@reversiblemaps.ath.cx...

On 2009-03-31, kreed <kenreed1...@gmail.com> wrote:

I also told him of the "flashing" problem, he remembered hearing
complaints of intermittently flashing CFL's in bedrooms,  - noticed
because he noticed in a property inspection one woman had stuck a
black cloth into a wall light fitting to avoid having to put up with
flashing at night while trying to sleep. (great potential fire hazard
I reckon)

Not surprisingly, the electricians they use didn't seem to have a clue
as to why.  I advised a double pole switch.

that sounds like overkill and would be kind of hard to retrofit.

If you have a neutral at the switch plate, a single pole changeover will
do - simply switch the lamp feed from live to neutral

In the serious bodge category, if there's no neutral switch the feed to
earth (I wonder how many lamps it would take to trip a ELCB?).

Yes, that is correct and would stop the CFL from flashing (by shorting
together the 2 lamp wires when power is off) , but the problem is that
you cannot safely connect both the active and neutral directly to the
2 "throw" terminals of a standard Australian light switch, there is a
high risk of arc / breakdown between the 2 throw terminals, leading to
a short and/or a fire.

DONT DO IT.


As I said in another post, using a resistor in series with the neutral
to the throw terminal, or wall plate type neon insert (subject to its
breakdown voltage being lower than the CFL's "start" voltage
threshold) is the only safe way I can think of achieving a safe result
with this method.

the ideal solution would be for CFL makers to put a "bleed" resistor
across the filter cap. I doubt it will happen though.

Note - If trying this in any other electrical system, note that as
well as the insulation breakdown switch, if you use any type of "make
before break" switch, you would cop a dead short circuit across the
supply - check the switch first before applying power.


probably wouldn't trip an ELCB, but I wouldnt try wiring anything to
the earth except things that are meant to be earthed. at least it
would probably trip the ELCB if the switch insulation failed.

 

[ian field]

"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:gr1pa0$p0u$1@reversiblemaps.ath.cx...

On 2009-04-02, Davo <Dave@gmail.com> wrote:
ian field wrote:
"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:gqvfc8$tu6$3@reversiblemaps.ath.cx...
On 2009-03-31, kreed <kenreed1999@gmail.com> wrote:
I also told him of the "flashing" problem, he remembered hearing
complaints of intermittently flashing CFL's in bedrooms, - noticed
because he noticed in a property inspection one woman had stuck a
black cloth into a wall light fitting to avoid having to put up with
flashing at night while trying to sleep. (great potential fire hazard
I reckon)

Not surprisingly, the electricians they use didn't seem to have a clue
as to why. I advised a double pole switch.
that sounds like overkill and would be kind of hard to retrofit.


I'd suggest the wiring has been incorrectly done in the first place and
needs to be fixed. A big part of the wiring regulations now states that
if you have knowledge of bad wiring you have a legal obligation to get
it fixed or disconnected. You can't "turn a blind eye" so to speak. In
industry this is known as "duty of care".

Last time I checked it was perfectly legal to run the
live(red)+neutral(black)
+earth(green+yellow) from the fusebox to the light fixture and then run a
branch from there to the switch with a 2 conductor cable with just
live(red)
and switched live(white)

As has been observed the capacitance between live and switched makes this
setup
less than ideal for use with CFLs.

If you have a neutral at the switch plate, a single pole changeover will
do - simply switch the lamp feed from live to neutral

This is the sort of action that kills people. An electrician doing this
would probably end up in gaol on a manslaughter charge.

In the serious bodge category, if there's no neutral switch the feed to
earth (I wonder how many lamps it would take to trip a ELCB?).

Not sure what you mean here but domestic ELCBs trip at 30mA.

I doubt a cfl would conduct significant current if wired between earth
and neutral, it does seem like a bodge though.

would putting a Class X2 capacitor in parallel with the lamp be
better?

It probably would since the flickering is most likely due to capacitance
between the wires, its a simple matter to shunt the tiny current with a
bigger capacitance than the wiring. The main difficulty is safely housing
the capacitor in the light fitting, if there's a neutral behind the switch
plate that might make things easier.

 

[ian field]

"Davo" <Dave@gmail.com> wrote in message
news:49d48b12_7@news.peopletelecom.com.au...

KR wrote:
On Apr 2, 1:21 am, "ian field" <gangprobing.al...@ntlworld.com> wrote:
"Jasen Betts" <ja...@xnet.co.nz> wrote in message

news:gqvfc8$tu6$3@reversiblemaps.ath.cx...

On 2009-03-31, kreed <kenreed1...@gmail.com> wrote:
I also told him of the "flashing" problem, he remembered hearing
complaints of intermittently flashing CFL's in bedrooms, - noticed
because he noticed in a property inspection one woman had stuck a
black cloth into a wall light fitting to avoid having to put up with
flashing at night while trying to sleep. (great potential fire hazard
I reckon)
Not surprisingly, the electricians they use didn't seem to have a clue
as to why. I advised a double pole switch.
that sounds like overkill and would be kind of hard to retrofit.
If you have a neutral at the switch plate, a single pole changeover will
do - simply switch the lamp feed from live to neutral

In the serious bodge category, if there's no neutral switch the feed to
earth (I wonder how many lamps it would take to trip a ELCB?).


Yes, that is correct and would stop the CFL from flashing (by shorting
together the 2 lamp wires when power is off) , but the problem is that
you cannot safely connect both the active and neutral directly to the
2 "throw" terminals of a standard Australian light switch, there is a
high risk of arc / breakdown between the 2 throw terminals, leading to
a short and/or a fire.

DONT DO IT.


As I said in another post, using a resistor in series with the neutral
to the throw terminal, or wall plate type neon insert (subject to its
breakdown voltage being lower than the CFL's "start" voltage
threshold) is the only safe way I can think of achieving a safe result
with this method.

the ideal solution would be for CFL makers to put a "bleed" resistor
across the filter cap. I doubt it will happen though.

Note - If trying this in any other electrical system, note that as
well as the insulation breakdown switch, if you use any type of "make
before break" switch, you would cop a dead short circuit across the
supply - check the switch first before applying power.


probably wouldn't trip an ELCB, but I wouldnt try wiring anything to
the earth except things that are meant to be earthed. at least it
would probably trip the ELCB if the switch insulation failed.

Off the top of my head, since I don't have the regulations handy, it's
illegal to connect the earth to the neutral anywhere except at the neutral
bar link in the supply switchboard. Additionally, by law, the system has
to pass a test process before power is applied, and connecting the neutral
to the earth at any place besides the switchboard would cause the system
to fail the test.

Who said anything about connecting earth and neutral together?

 

[Davo]

ian field wrote:

"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:gqvfc8$tu6$3@reversiblemaps.ath.cx...
On 2009-03-31, kreed <kenreed1999@gmail.com> wrote:
I also told him of the "flashing" problem, he remembered hearing
complaints of intermittently flashing CFL's in bedrooms, - noticed
because he noticed in a property inspection one woman had stuck a
black cloth into a wall light fitting to avoid having to put up with
flashing at night while trying to sleep. (great potential fire hazard
I reckon)

Not surprisingly, the electricians they use didn't seem to have a clue
as to why. I advised a double pole switch.
that sounds like overkill and would be kind of hard to retrofit.

I'd suggest the wiring has been incorrectly done in the first place and
needs to be fixed. A big part of the wiring regulations now states that
if you have knowledge of bad wiring you have a legal obligation to get
it fixed or disconnected. You can't "turn a blind eye" so to speak. In
industry this is known as "duty of care".

If you have a neutral at the switch plate, a single pole changeover will
do - simply switch the lamp feed from live to neutral

This is the sort of action that kills people. An electrician doing this
would probably end up in gaol on a manslaughter charge.

In the serious bodge category, if there's no neutral switch the feed to
earth (I wonder how many lamps it would take to trip a ELCB?).

Not sure what you mean here but domestic ELCBs trip at 30mA.