Hi folks,

I will shortly be introducing my (detached) garage to the wonders of
modern electricity. Short of trial and error, does anyone know of a
good rule of thumb for deciding how much light and heat is required
per m^2? The garage is only slightly larger than a car, and will be
used for tinkering and storage (but not of cars), and perhaps the odd
bit of tumble-drying.

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

I guess it would be nice to know this in general, since my whole house
appears to be underlit and underheated.

TIA, Rich

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

You will need additional light in a garage compared to living spaces, as
they are invariably used as working areas. For a simple 4.8m x 2.4m garage,
a twin tube 58W fitting would provide oodles. 3 singles spaced throughout
would be even better, but might be over the top, depending on what you
wanted to use the room for.

As for heating, it is more important to get the insulation sorted than
increase the heater power. If you can spare 50mm of every wall, it is well
worth sticking some slabs of celotex on. Draft proof and insulate the door
too. (Don't forget the ceiling!) Then, 3kW will be well overpowered for the
garage (although it will get it to temperature quickly). A wall mounted
convector with timer and THERMOSTAT (essential!) would be inobtrusive, quiet
and effective.

Christian.

Christian McArdle wrote:
Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

You will need additional light in a garage compared to living spaces, as
they are invariably used as working areas. For a simple 4.8m x 2.4m garage,
a twin tube 58W fitting would provide oodles. 3 singles spaced throughout
would be even better, but might be over the top, depending on what you
wanted to use the room for.

Also, usually, garages have dark walls and ceilings, darker than those
typically found in a house anyway. Fluorescent fittings are so cheap
that you might as well go abit OTT.

--
Chris Green )

In message ,
writes
Christian McArdle wrote:
Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

You will need additional light in a garage compared to living spaces, as
they are invariably used as working areas. For a simple 4.8m x 2.4m garage,
a twin tube 58W fitting would provide oodles. 3 singles spaced throughout
would be even better, but might be over the top, depending on what you
wanted to use the room for.

Also, usually, garages have dark walls and ceilings, darker than those
typically found in a house anyway. Fluorescent fittings are so cheap
that you might as well go abit OTT.

Indeed.

I have fluorescent fittings ( 4 'bulbs' - 2 are old single 4 ft
fittings, one is a modern twin 58W fitting) in my garage and while for
general use it's ok, it's not quite enough IMO. particularly at each
end. Though possibly I could have arranged them slightly better

Doing it from scratch I'd probably have 4 twin fittings - that ought to
do It :-)

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.
--
Chris French, Leeds

On Mon, 1 Dec 2003 13:20:02 +0000, chris French
wrote:

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.

Could I add my support for that idea too! Thanks to someone who was
very helpful with that suggestion a couple of months ago I splashed
some white paint on the garage walls and it did indeed make a big
difference.

PoP

(Rich) wrote in message . com...
Hi folks,

I will shortly be introducing my (detached) garage to the wonders of
modern electricity. Short of trial and error, does anyone know of a
good rule of thumb for deciding how much light and heat is required
per m^2? The garage is only slightly larger than a car, and will be
used for tinkering and storage (but not of cars), and perhaps the odd
bit of tumble-drying.

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

I guess it would be nice to know this in general, since my whole house
appears to be underlit and underheated.

TIA, Rich


Hi

I'd make it one 5' fluorescent light plus a white ceiling to soften
the light. More enthusiastic folk might run to 2 strips, but 3.... no,
just plain unpleasant.


Regards, NT

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.

It does help, considerably.

Until you put up floor to ceiling shelves, racks and cupboards ...

Mary
--
Chris French, Leeds

N. Thornton wrote:

I'd make it one 5' fluorescent light plus a white ceiling to soften
the light. More enthusiastic folk might run to 2 strips, but 3.... no,
just plain unpleasant.

In my workshop (approx single garage sort of size) I went for 4 x 5' 58W
single tubes - one on each end wall, two equally spaced in the middle.
With the ceiling and walls painted off-white I find these give a nice
even light for working in.

It's not just the level of light that counts - but also having it
arriving from several directions so that you are not always working in
your shadow.

(when I installed the lights I put them on a double switch so that I
could switch two pairs of two independently - I have so far never found
the desire to only use one set on its own when working in there -
although being able to switch only half on is OK when you are just
popping out to get a tool or something).

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Rich wrote:

Hi folks,

I will shortly be introducing my (detached) garage to the wonders of
modern electricity. Short of trial and error, does anyone know of a
good rule of thumb for deciding how much light and heat is required
per m^2? The garage is only slightly larger than a car, and will be
used for tinkering and storage (but not of cars), and perhaps the odd
bit of tumble-drying.

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

I guess it would be nice to know this in general, since my whole house
appears to be underlit and underheated.



General 'one strip light' lighting will be enough to see what yopu are
doing but not for detail work.

I think about 20W/meter squared lighting with incandescent, and about
one tenth for fluorescent, so assumeing 6 sq meters, somethimng like a
pair of 100W bulbs, or a 20W fluorescent strip probly.

If insulated very well, 30W/meter squared will get you a warm room able
to rise 25 degrees above ambient - say u values of around 0.5. A
draughty garage will need at least ten times that :-) Say 300w/m^2, so
your 3Kw heater sounds not so far out after all....


TIA, Rich

"N. Thornton" wrote in message
om...
(Rich) wrote in message
. com...
Hi folks,

I will shortly be introducing my (detached) garage to the wonders of
modern electricity. Short of trial and error, does anyone know of a
good rule of thumb for deciding how much light and heat is required
per m^2? The garage is only slightly larger than a car, and will be
used for tinkering and storage (but not of cars), and perhaps the odd
bit of tumble-drying.

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

I guess it would be nice to know this in general, since my whole house
appears to be underlit and underheated.

TIA, Rich


Hi

I'd make it one 5' fluorescent light plus a white ceiling to soften
the light. More enthusiastic folk might run to 2 strips, but 3.... no,
just plain unpleasant.


Regards, NT

Also "nice" bulk head light on the wall over a workbench works wonders for a
few quid. It also reduces the flicker when tinkering, especially with a
circular saw.

--
Adam

In message , Mary Fisher
writes

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.

It does help, considerably.

Until you put up floor to ceiling shelves, racks and cupboards ...

Well yes :-)

Paint all the boxes etc. on the shelves white as well?
--
Chris French, Leeds

chris French wrote:
In message , Mary Fisher
writes

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.

It does help, considerably.

Until you put up floor to ceiling shelves, racks and cupboards ...

Well yes :-)

Paint all the boxes etc. on the shelves white as well?

Dangle white sheets over the fronts of the racks, keeps the light levels up
and the dust off.

--
James...
http://www.jameshart.co.uk/

On Mon, 1 Dec 2003 19:19:43 +0000, chris French
wrote:

In message , Mary Fisher
writes

Painting the walls white would probably help as well, we painted our
shed white inside and it really made it seem brighter inside.

It does help, considerably.

Until you put up floor to ceiling shelves, racks and cupboards ...

Well yes :-)

Paint all the boxes etc. on the shelves white as well?

.... or stick white roses on them ??



..andy

To email, substitute .nospam with .gl

ARWadsworth wrote in message
...

"N. Thornton" wrote in message
om...
(Rich) wrote in message
. com...
snip
Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.
snip
Hi
I'd make it one 5' fluorescent light plus a white ceiling to soften
the light. More enthusiastic folk might run to 2 strips, but 3.... no,
just plain unpleasant.

Also "nice" bulk head light on the wall over a workbench works wonders for
a
few quid. It also reduces the flicker when tinkering, especially with a
circular saw.

If you are planning to have a lathe, pillar drill or things that turn, an
ordinary light bulb of some sort would be a must IMO, last thing you need is
to be lulled into thinking something has stopped when it is still turning.

This was last demonstrated to me by an old metalwork teacher, oh so many
moons ago. I think it is based around the same principal shown in old
movies when the wheels on a car give the idea of being stopped or going in
the opposite direction, when they are really going forward.
--
Big Al - The Peoples Pal

John Rumm wrote in message ...
N. Thornton wrote:

I'd make it one 5' fluorescent light plus a white ceiling to soften
the light. More enthusiastic folk might run to 2 strips, but 3.... no,
just plain unpleasant.

In my workshop (approx single garage sort of size) I went for 4 x 5' 58W
single tubes - one on each end wall, two equally spaced in the middle.
With the ceiling and walls painted off-white I find these give a nice
even light for working in.

Ouch.


It's not just the level of light that counts - but also having it
arriving from several directions so that you are not always working in
your shadow.

Yes. Mounting a light in the middle of the ceiling, bulb pointing
down, is not good. Mounting it the other way up with a white painted
ceiling helps a lot. If you go for multiple lights, the best option is
to mount them on the wall high up, with tube shielded from view, and
the light bouncing off the ceiling and upper wall. Trough or shelf.

Fl lights last so long that the tubes need to be cleaned occasionally,
or the light output falls a lot. Stay well away from 'cool white'
tubes.


(when I installed the lights I put them on a double switch so that I
could switch two pairs of two independently

I'd definitely recommend that.


Regards, NT

On Tue, 2 Dec 2003 00:57:53 -0000, "Big Al - The Peoples Pal"
wrote:

If you are planning to have a lathe, pillar drill or things that turn, an
ordinary light bulb of some sort would be a must IMO, last thing you need is
to be lulled into thinking something has stopped when it is still turning.

Something to do with harmonic frequency no doubt. That is, if the
light is flickering at 50Hz and the power tool is rotating at some
direct multiple of that (say 200Hz) then it will appear to be still as
your eye is getting the rotating tool or chuck snapshot in the same
position each time.

PoP

If you are planning to have a lathe, pillar drill or things that turn,
an ordinary light bulb of some sort would be a must IMO, last thing
you need is to be lulled into thinking something has stopped when it
is still turning.

This can be overcome by using fittings incorporating an electronic ballast.
This runs the tube at a much higher frequency (i.e. many kHz) and eliminates
the stroboscopic effect. They can also be much easier on the eye to those
sensitive to flicker.

Christian.

N. Thornton wrote:


I just mounted up 4 35W single fluro tubes in my loft - about 28 meters
long (L bend in teh middle) and 4.5meters wide.

Its adequate to see what you are doing. Not enough for close detailed
work tho.

If that helps. Works out at 1W per square meter.

PoP wrote:

On Tue, 2 Dec 2003 00:57:53 -0000, "Big Al - The Peoples Pal"
wrote:


If you are planning to have a lathe, pillar drill or things that turn, an
ordinary light bulb of some sort would be a must IMO, last thing you need is
to be lulled into thinking something has stopped when it is still turning.


Something to do with harmonic frequency no doubt. That is, if the
light is flickering at 50Hz and the power tool is rotating at some
direct multiple of that (say 200Hz) then it will appear to be still as
your eye is getting the rotating tool or chuck snapshot in the same
position each time.



The flicker rate is double mains freq - 100hz. Long persistence
phosphors help a lot. The ones I put in today are not bad at all.
However, I would still not use em arond totating machinery.




PoP

Christian McArdle wrote:

If you are planning to have a lathe, pillar drill or things that turn,
an ordinary light bulb of some sort would be a must IMO, last thing
you need is to be lulled into thinking something has stopped when it
is still turning.


This can be overcome by using fittings incorporating an electronic ballast.
This runs the tube at a much higher frequency (i.e. many kHz) and eliminates
the stroboscopic effect. They can also be much easier on the eye to those
sensitive to flicker.


Mmm. I wonder if that's what I have.



Christian.

The Natural Philosopher wrote:

The flicker rate is double mains freq - 100hz. Long persistence
phosphors help a lot. The ones I put in today are not bad at all.
However, I would still not use em arond totating machinery.

IMBW but I was under the impression that modern fl lights had high
frequency ballasts to eliminate this problem? I must admit to never
having observed the effect myself in my workshop which is all fl
lighting and I am usually very sensitive to flicker (find 50Hz TV quite
objectionable for example).

Then again I can usually tell when a tool is running due to the noise!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

N. Thornton wrote:

Fl lights last so long that the tubes need to be cleaned occasionally,
or the light output falls a lot. Stay well away from 'cool white'
tubes.

Something else I forgot mention - it is well worth going for a fitting
that has a nice tight fitting diffuser. Not only will this make the
light nicer to work in, and keep the dust of the tubes, but more
importantly it has saved a tube on a number of occasions when I have
been rotating a large bit of stock and forgot that it was longer than
the height of the lights!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tue, 02 Dec 2003 18:28:08 +0000, The Natural Philosopher
wrote:

Christian McArdle wrote:

If you are planning to have a lathe, pillar drill or things that turn,
an ordinary light bulb of some sort would be a must IMO, last thing
you need is to be lulled into thinking something has stopped when it
is still turning.


This can be overcome by using fittings incorporating an electronic ballast.
This runs the tube at a much higher frequency (i.e. many kHz) and eliminates
the stroboscopic effect. They can also be much easier on the eye to those
sensitive to flicker.


Mmm. I wonder if that's what I have.

You would know from the price tag and the weight.......

Generally you specifically have to ask at electrical wholesalers for
electronic ballast fittings or they assume that you just want the
cheap choke versions.




Christian.





..andy

To email, substitute .nospam with .gl

Generally you specifically have to ask at electrical wholesalers for
electronic ballast fittings or they assume that you just want the
cheap choke versions.

Profit making SOBs how dare they do this?

The other advantage of putting a bulk head light over the workbench/pasting
table/B&D workmate is that for the £3 it takes to fit you get a light in
front of you not behind you.


--
Adam

Andy Hall wrote:
On Tue, 02 Dec 2003 18:28:08 +0000, The Natural Philosopher
wrote:

Christian McArdle wrote:

If you are planning to have a lathe, pillar drill or things that turn,
an ordinary light bulb of some sort would be a must IMO, last thing
you need is to be lulled into thinking something has stopped when it
is still turning.


This can be overcome by using fittings incorporating an electronic ballast.
This runs the tube at a much higher frequency (i.e. many kHz) and eliminates
the stroboscopic effect. They can also be much easier on the eye to those
sensitive to flicker.


Mmm. I wonder if that's what I have.

You would know from the price tag and the weight.......

Generally you specifically have to ask at electrical wholesalers for
electronic ballast fittings or they assume that you just want the
cheap choke versions.

They are getting a lot cheaper now though, I just bought some 5ft
fittings with electronic ballast for £11.75 (I think it was) from
Denmans.

--
Chris Green )

"Big Al - The Peoples Pal" wrote in message t...

Also "nice" bulk head light on the wall over a workbench works wonders for
a
few quid. It also reduces the flicker when tinkering, especially with a
circular saw.

If you are planning to have a lathe, pillar drill or things that turn, an
ordinary light bulb of some sort would be a must IMO, last thing you need is
to be lulled into thinking something has stopped when it is still turning.

This was last demonstrated to me by an old metalwork teacher, oh so many
moons ago. I think it is based around the same principal shown in old
movies when the wheels on a car give the idea of being stopped or going in
the opposite direction, when they are really going forward.

Or investigate replacing the ballasts in the fluorescents with
electronic ballasts that have a much higher operating frequency so
don't show this effect.

Of course if you are using machinery then you might also want to
consider some form of emergency lighting so that if the power goes off
you are not left in the dark with a still spinning blade nearby.

I am going through this process at the moment. Can anyone point me in
the direction of some form of UPS for lighting so that it will all
stay on? Only needs to be for ten minutes or so. Non-maintained
bulkheads are cheap enough but I would rather trade light output for
time.

Andrew

On 3 Dec 2003 04:50:39 -0800, (Andrew May)
wrote:


Or investigate replacing the ballasts in the fluorescents with
electronic ballasts that have a much higher operating frequency so
don't show this effect.

I've done this, but realised later that it's more expensive than just
replacing the entire fitting.



Of course if you are using machinery then you might also want to
consider some form of emergency lighting so that if the power goes off
you are not left in the dark with a still spinning blade nearby.

I am going through this process at the moment. Can anyone point me in
the direction of some form of UPS for lighting so that it will all
stay on? Only needs to be for ten minutes or so. Non-maintained
bulkheads are cheap enough but I would rather trade light output for
time.

Andrew

I looked at this too, but couldn't find one. In the end I found
that WF Electrical had own-brand 55w fittings, maintained, with
protective covers for under £100 before discount.

I put two of them spaced out among regular fittings on the ceiling of
the workshop and a small 8W one near the door. This is plenty to
cover the safety aspects.

I couldn't find a UPS with reasonable power output at this sort of
price. Those intended for IT purposes are short duration, higher
power but cost more......





..andy

To email, substitute .nospam with .gl

(Rich) wrote in message . com...
Hi folks,

I will shortly be introducing my (detached) garage to the wonders of
modern electricity. Short of trial and error, does anyone know of a
good rule of thumb for deciding how much light and heat is required
per m^2? The garage is only slightly larger than a car, and will be
used for tinkering and storage (but not of cars), and perhaps the odd
bit of tumble-drying.

Part of me wants to say "3 strip lights and a 3kW heater", but I can't
help thinking there must be a more scientific way.

I guess it would be nice to know this in general, since my whole house
appears to be underlit and underheated.

TIA, Rich

Thanks for all the suggestions.

I hadn't thought of a bulkhead light as well as strips - good plan.
And despite watching all those property programmes, I hadn't thought
to paint the walls white either.

Screwfix beckons...

separate light switching. I was planning on using a pull-cord for
the lights. Is there such a thing as a 'pull once for light A, twice
for light B, thrice for lights A+B and four times for lights off' pull
switch.

And for that matter, has anyone got any tales, good or bad, about the
Screwfix Garage Consumer Unit? Its a 40A RCD unit with two (6A and
16A) MCBs. I gather there might be some discrimination problems
connecting it to my house CU (via a spare fuseway) which is itself
RCD-protected. Effectively, the garage circuits would be protected by
their MCBs, the RCD in the garage consumer unit, the MCB in the house
CU, and the RCD in the house CU.

On 3 Dec 2003 06:27:04 -0800, (Rich) wrote:



I hadn't thought of a bulkhead light as well as strips - good plan.
And despite watching all those property programmes, I hadn't thought
to paint the walls white either.

Screwfix beckons...

separate light switching. I was planning on using a pull-cord for
the lights. Is there such a thing as a 'pull once for light A, twice
for light B, thrice for lights A+B and four times for lights off' pull
switch.

You could implement this with impulse relays, but it would not be a
cheap option.


And for that matter, has anyone got any tales, good or bad, about the
Screwfix Garage Consumer Unit? Its a 40A RCD unit with two (6A and
16A) MCBs.

Is that enough or are you sure it will be enough for future
requirements.

I gather there might be some discrimination problems
connecting it to my house CU (via a spare fuseway) which is itself
RCD-protected. Effectively, the garage circuits would be protected by
their MCBs, the RCD in the garage consumer unit, the MCB in the house
CU, and the RCD in the house CU.

There is no discrimination in this if the RCDs are all of the same
type, so what then trips out will be arbitrary. You may not want
this.


..andy

To email, substitute .nospam with .gl

On Wed, 03 Dec 2003 14:56:26 +0000, Andy Hall
wrote:

And for that matter, has anyone got any tales, good or bad, about the
Screwfix Garage Consumer Unit? Its a 40A RCD unit with two (6A and
16A) MCBs.

Is that enough or are you sure it will be enough for future
requirements.

I've got a similar model in my garage (not identical) with 2 RCD
protected circuits - 6A and 16A.

I just got thru wiring an electric fan heater in there today. Being a
3KW jobbie it's going to pull some 12A when operational. That leaves
4A or about 1KW before the RCD pops its clogs, which will compromise
some of my power tools!

Haven't thought about this problem before (I have to admit I assumed
it would be a 30A supply). I'm wondering whether a solution is as
simple as uprating the RCD, or am I going to have to consider other
alternatives?

Garage is fed from an armoured cable from the house - I'll have to
check this further to make sure of capacity but it looks to me to be
beefy enough to handle a higher load. I know the armoured cable comes
thru the house consumer unit 100A RCD because (with the circuit RCD
switched off) the 100A RCD tripped the house out when I chopped thru
the mains cable in the garage - presumably due to some small current
flowing between live and earth even with the circuit off.

PoP

In uk.d-i-y, PoP wrote:



..................................... I know the armoured cable comes
thru the house consumer unit 100A RCD because (with the circuit RCD
switched off) the 100A RCD tripped the house out when I chopped thru
the mains cable in the garage - presumably due to some small current
flowing between live and earth even with the circuit off.

No, the live was isolated. But the neutral wasn't (single-pole breaker,
neutrals commoned on the RCD side). When you chopped through the cable,
you gave the current flowing back to the neutral block and back to
the balance-detection circuitry of the RCD another path back to earth
(through the N conductor of the SWA and back down the earth conductor).
Doesn't take much of an imbalance to make the RCD pop, right?

(This comes up often enough that Someone ought to write it up for the
FAQ under "why does my RCD pop when I've disconnected a circuit with
the MCB?"...)

Stefek

PoP wrote:
On Wed, 03 Dec 2003 14:56:26 +0000, Andy Hall
wrote:

And for that matter, has anyone got any tales, good or bad, about the
Screwfix Garage Consumer Unit? Its a 40A RCD unit with two (6A and
16A) MCBs.

Is that enough or are you sure it will be enough for future
requirements.

I've got a similar model in my garage (not identical) with 2 RCD
protected circuits - 6A and 16A.

I just got thru wiring an electric fan heater in there today. Being a
3KW jobbie it's going to pull some 12A when operational. That leaves
4A or about 1KW before the RCD pops its clogs, which will compromise
some of my power tools!

Haven't thought about this problem before (I have to admit I assumed
it would be a 30A supply). I'm wondering whether a solution is as
simple as uprating the RCD, or am I going to have to consider other
alternatives?

You've got your RCDs and MCBs confused, I think.

The 6 amp and 16 amp rated things in your garage CU are MCBs, that is
they're overcurrent devices. Hopefully there is *also* an RCD
protecting at least the 16 amp sockets circuit. The usual arrangement
is that the incomer switch device on the mini CU is an RCD (rated at
30mA trip current) which feeds the two MCBs. (A less likely
possibility is that you have RCBOs, combined RCD/MCB devices)

One fairly simple approach would be to uprate the 16A MCB to a 20A
one, this would be 'correct' for a radial circuit wired in 2.5sq mm
feeding sockets. This would give 8 amps or so 'headroom' for your
machinery. As long as the feed from the house is also at least 2.5sq
mm and isn't too long then this strikes me as the obvious solution.

Garage is fed from an armoured cable from the house - I'll have to
check this further to make sure of capacity but it looks to me to be
beefy enough to handle a higher load. I know the armoured cable comes
thru the house consumer unit 100A RCD because (with the circuit RCD
switched off) the 100A RCD tripped the house out when I chopped thru
the mains cable in the garage - presumably due to some small current
flowing between live and earth even with the circuit off.

It would be touching neutral to earth that tripped the house RCD.

--
Chris Green )

On 3 Dec 2003 23:10:42 GMT, wrote:

No, the live was isolated. But the neutral wasn't (single-pole breaker,
neutrals commoned on the RCD side). When you chopped through the cable,
you gave the current flowing back to the neutral block and back to
the balance-detection circuitry of the RCD another path back to earth
(through the N conductor of the SWA and back down the earth conductor).
Doesn't take much of an imbalance to make the RCD pop, right?

Thanks for explaining. I did wonder!

(This comes up often enough that Someone ought to write it up for the
FAQ under "why does my RCD pop when I've disconnected a circuit with
the MCB?"...)

And there was me thinking I must have been charged up with static.....

PoP

Hi


Theres another solution to flicker other than en electronic ballast.
That is to have 2 lights close by, or in same fitting, with one fed
thru a series capacitor. This shifts the phase of one of the lights
and gets rid of most of the flicker. Result is the optical illusion
problem is gone. The other traditional solution is to have an
incandescent worklight over each lathe etc, as well as th general fl
lighting.

Regards, NT

"N. Thornton" wrote in message
om...
Hi


Theres another solution to flicker other than en electronic ballast.
That is to have 2 lights close by, or in same fitting, with one fed
thru a series capacitor. This shifts the phase of one of the lights
and gets rid of most of the flicker. Result is the optical illusion
problem is gone. The other traditional solution is to have an
incandescent worklight over each lathe etc, as well as th general fl
lighting.

Regards, NT

Surely it isn't the phase that is a problem - shifting the phase will only
move the 'frozen image' round the circle of rotation. The problem is that
the frequency is or is close to a multiple or sub multiple of the rotational
speed. (If close then the frozen image will progress slowly)

Surely it isn't the phase that is a problem - shifting the phase will
only
move the 'frozen image' round the circle of rotation.

But if you have two lights, with the phase rotated 90 degrees, you'll find
that as one light fades out, the other is just coming in. This is similar to
why a 6 cylinder car engine is smoother than a 4 cylinder one.

Christian.

Christian McArdle wrote:

Surely it isn't the phase that is a problem - shifting the phase will

only

move the 'frozen image' round the circle of rotation.


But if you have two lights, with the phase rotated 90 degrees, you'll find
that as one light fades out, the other is just coming in. This is similar to
why a 6 cylinder car engine is smoother than a 4 cylinder one.

Christian.




Sadly phases are not no dgerees out of phase, but 120.

A three tube three ballast three phase light fitting would be better,
but an elelctronic ballast is - er - cheaper?

On Fri, 05 Dec 2003 10:50:02 +0000, The Natural Philosopher
wrote:

Christian McArdle wrote:

Surely it isn't the phase that is a problem - shifting the phase will

only

move the 'frozen image' round the circle of rotation.


But if you have two lights, with the phase rotated 90 degrees, you'll find
that as one light fades out, the other is just coming in. This is similar to
why a 6 cylinder car engine is smoother than a 4 cylinder one.

Christian.




Sadly phases are not no dgerees out of phase, but 120.

A three tube three ballast three phase light fitting would be better,
but an elelctronic ballast is - er - cheaper?

and will facilitate the light firing up quickly and brightly when it's
cold........



..andy

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"Andrew Mawson" wrote in message ...
"N. Thornton" wrote in message
om...
Hi


Theres another solution to flicker other than en electronic ballast.
That is to have 2 lights close by, or in same fitting, with one fed
thru a series capacitor. This shifts the phase of one of the lights
and gets rid of most of the flicker. Result is the optical illusion
problem is gone. The other traditional solution is to have an
incandescent worklight over each lathe etc, as well as th general fl
lighting.

Regards, NT

Surely it isn't the phase that is a problem - shifting the phase will only
move the 'frozen image' round the circle of rotation. The problem is that
the frequency is or is close to a multiple or sub multiple of the rotational
speed. (If close then the frozen image will progress slowly)

What happens with these 2 tube setups is that one runs out of phase to
the other one, and the light from the 2 add. The result is that you
get light output for the majority of the cycle, thus the frozen image
is no longer frozen, it is a safe blur instead.

Regards, NT