brownout experience...can someone help explain please?

[aanon]

hello all,

i'm just dropping in here in the hope one of you might be able to
explain something for me.

last night here in west ryde (sydney) we had a blackout. well, at first
i thought it was a blackout...then after my eyes adjusted i noticed
that, although most of my appliances had gone off, the lights in the
house were still emitting a very faint red light. i thought it might
have been residual heat but, sure enough, when i turned on lights in
other rooms they all had the same faint output.

so, would this be because there was still a small voltage powering the
lights? what sort of grid malfunction might have caused this?

while i was wondering such things, i reached over to switch off my
bedside lamp. this lamp has one of those fluoroscent power saving bulbs
which can go in a regular light socket. now, when i placed my hand on
the lamp to switch it off, the bulb became much brighter. when i
actually touched the glass tubing of the fluoroscent bulb the light in
one of the 3 loops of glass tubing actually came up to a bright white
output. as long as i was touching it the light was bright.

now i'm truly at a loss for explanations. i wasn't charged up with
static electricity at all. i was lying on a mattress so i can't see how
my body could have been completing any circuit. can someone help
explain why my touch was brightening the fluorescent lamp? and why only
1 of the three loops of the glass tube?

many thanks in advance,

aanon

 

[jasen]

last night here in west ryde (sydney) we had a blackout. well, at first
i thought it was a blackout...then after my eyes adjusted i noticed
that, although most of my appliances had gone off, the lights in the
house were still emitting a very faint red light. i thought it might
have been residual heat but, sure enough, when i turned on lights in
other rooms they all had the same faint output.

so, would this be because there was still a small voltage powering the
lights? what sort of grid malfunction might have caused this?

how much do you know about three-phase electricity?

 

[aanon]

hi jasen,

i'm glad to have gotten some response on the question...thank you.

the answer to your question is: next to nothing. my knowledge of
electricity goes no further than year 12 physics.

what if i skip the question of what happened in the grid to cause the
brownout...can you help me with what was happening with the fluoroscent
lamp?

all the best, aanon

 

[jasen]

hi jasen,

i'm glad to have gotten some response on the question...thank you.

the answer to your question is: next to nothing. my knowledge of
electricity goes no further than year 12 physics.

That makes it kind of hard to explain, have a look at the wikipedia page on
three-phase electricity, actually the wikipedia page while technically
acurate was pretty confusing last time I looked, if you've got another
reference that'd be worth a look too.

Then consider this,

When one of the phase supplies gets disconnected from the local electricity
grid, the whole system becomes unbalanced some electriftiy will flow through
three-phase devices into the "unpowered" phase putting a small voltage on it,
at the same time the two other phases also drop to a lower voltage as third
phase isn't there to balance everything.

what if i skip the question of what happened in the grid to cause the
brownout...can you help me with what was happening with the fluoroscent
lamp?

It's a capacitance effect, the presence of your hand effects the electric
field iniside the glass tube making it easier for the tube to "fire".

oh yeah, "top posting" (with edits) is reccomended in most of usenet.

Bye.
Jasen

 

[Tsunami Australia]

That makes it kind of hard to explain, have a look at the wikipedia page
on
three-phase electricity, actually the wikipedia page while technically
acurate was pretty confusing last time I looked, if you've got another
reference that'd be worth a look too.

Then consider this,

When one of the phase supplies gets disconnected from the local
electricity
grid, the whole system becomes unbalanced some electriftiy will flow
through
three-phase devices into the "unpowered" phase putting a small voltage on
it,
at the same time the two other phases also drop to a lower voltage as
third
phase isn't there to balance everything.


It's a capacitance effect, the presence of your hand effects the electric
field iniside the glass tube making it easier for the tube to "fire".


oh yeah, "top posting" (with edits) is reccomended in most of usenet.

Bye.
Jasen

Now that's something that's had me for a whilst, the low power during
blackouts. What you've said re 3phase appliances makes a bit of sense and
would explain why each time it happens around here, there is only 50v or so
coming out of the point. We have a fair whack of 3phase gear around here,
dairys, the pub etc etc.

 

[Phil Allison]

"Tsunami Australia"

Now that's something that's had me for a whilst, the low power during
blackouts. What you've said re 3phase appliances makes a bit of sense and
would explain why each time it happens around here, there is only 50v or
so coming out of the point.

** Imagine the phase outage is PRIOR to the transformer serving your home
with 240 volts.

Ever notice a 3 phase tranny has only one core.




........ Phil