Hi,

I had this done at my old house, and would like to have the same
again. I thought how hard can it be, so I'm doing it myself this time.
The last place had the bar code left on the boards, so I know what to
get there. The only question I have really is about how to re-wire the
lighting? The current setup has the wires going across some boards
which I'm going to rip up and replace with the new flooring. I need to
re-do those wires, plus I guess stick in some sort of junction box so
that I can run a couple of lights up in the new loft along with a
switch by the loft hatch / ladder. I'm no electrician though. I've
previously installed a junction box to run a security light off the
front of the garage. That's the limit of my electrical experience:

* What kit I need to add in the new lighting along with a light
switch?
* How do I ensure that I'm not overloading the circuit?
* What have I missed?

All expertise gratefully received.

Cheers,

James

In an earlier contribution to this discussion,
James Abley wrote:

Hi,

I had this done at my old house, and would like to have the same
again. I thought how hard can it be, so I'm doing it myself this time.
The last place had the bar code left on the boards, so I know what to
get there. The only question I have really is about how to re-wire the
lighting? The current setup has the wires going across some boards
which I'm going to rip up and replace with the new flooring. I need to
re-do those wires, plus I guess stick in some sort of junction box so
that I can run a couple of lights up in the new loft along with a
switch by the loft hatch / ladder. I'm no electrician though. I've
previously installed a junction box to run a security light off the
front of the garage. That's the limit of my electrical experience:

* What kit I need to add in the new lighting along with a light
switch?
* How do I ensure that I'm not overloading the circuit?
* What have I missed?

All expertise gratefully received.

Cheers,

James

Is the garage part of the house, or detached? Is it heated?

If you have cables running over the joists, and you want to fit boards, you
have several options.

One is to drill holes through the centres of the joists, and to feed the
cables through. But you'd obviously have to disconnect and re-connect the
cables in order to do that. Also, there are rules about where - along the
length of the joists - you are allowed to drill holes without causing
structural problems.

If you *don't* want to disconnect the cables, the options are either to
notch the tops of the joists to accommodate the cables, or to fit battens to
the joists to space the boards clear of the cables. Again there are rules
about where you can cut notches.

When you box cables in, technically you are reducing their heat dissipation
capacity, and need to restrict the amount of current which they carry -
particularly if they pass through heated or insulated spaces - but it's
probably not an issue in your case.

With regards to extending the lighting circuit in order to install
additional lights and switches, you need to understand what you've already
got, and how it's wired - 'cos there's more than one accepted way of wiring
lighting circuits. Also, you need to distinguish between lighting and power
circuits. If you don't know what you're looking for, it's probably safest to
employ an electrician.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

In an earlier contribution to this discussion,
James Abley wrote:


Rules - as in building regs, or laws of nature rules?

Both. The building regs include rules about where holes and notches can be
in order not to compromise the structural integrity. They have been quoted
in this NG in the past, but I can't quote the exact details offhand.

I have the existing lighting circuit which carries 2 100W lights on
the garage joists. I need something similar up in the loft part so
that the newly floored part will be lit as well.

Assuming it uses 1 or 1.5 M^2 cable on a 5 or 6 amp fuse, there's no danger
of overloading it by adding another couple of lights.

The wife's asked
about me putting in new sockets on the power circuit - not sure about
that one!

In the garage, or in the house?

Your terminology worries me slightly when you say things like "it can't be
too difficult". I would be happier if you demonstrated that you knew how you
were going to go about it, and were simply seeking confirmation of your
method.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Roger Mills wrote:
In an earlier contribution to this discussion,
James Abley wrote:

Rules - as in building regs, or laws of nature rules?

Both. The building regs include rules about where holes and notches can be
in order not to compromise the structural integrity. They have been quoted
in this NG in the past, but I can't quote the exact details offhand.

From:

http://wiki.diyfaq.org.uk/index.php?...llation#Joists

"To meet current building regulations, the hole does not want to be more
than 0.25 times the total joist height - so a 2" hole on a 8" joist is
about the limit. It should also not go closer to the end of the joist
than 1/4 of the span (so no nearer than 1m from the end of a 4m joist),
and no closer to the centre than 0.4 times the span."



--
Cheers,

John.

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

James Abley wrote:

which I'm going to rip up and replace with the new flooring. I need to
re-do those wires, plus I guess stick in some sort of junction box so
that I can run a couple of lights up in the new loft along with a
switch by the loft hatch / ladder. I'm no electrician though. I've
previously installed a junction box to run a security light off the
front of the garage. That's the limit of my electrical experience:

Modern lighting circuits are usually wired using the "loop-in" method:

http://wiki.diyfaq.org.uk/index.php?...Loop-in_Wiring

Here each light position has a cable in, another to the switch, and
(unless its the last light on the circuit) another cable out to the next
light.

So adding more lights is really a case of taking a power feed from a
convenient light on the existing circuit and extending in the same way.
You can use a ceiling rose, the light fitting itself (if it has space
for the terminals) or a 4 terminal junction box to do the loop in wiring.


* What kit I need to add in the new lighting along with a light
switch?
* How do I ensure that I'm not overloading the circuit?

Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!


--
Cheers,

John.

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

James Abley wrote:

The wife's asked
about me putting in new sockets on the power circuit - not sure about
that one!


Not much to it really. There is no regulatory limit to the number of
sockets on a circuit. The only rule is the floor area served by the
circuit should not exceed 50m^2 for a radial, and 100m^2 for a ring
circuit.

If it is a radial circuit (probably wired in 2.5mm^2 T&E[1], and
protected at 20A, then just add a new wire connecting your new socket(s)
back to an existing one. (radials can have arbitrary branches at any
location - they don't have to be a linear daisy chain).

If its a ring circuit (same cable, but 32A protection), then join your
new sockets into the existing ring. You can do this at an existing
socket position using crimps[2] to join one of the existing cables to
one of the new ones, and the socket terminals themselves to join the
other existing cable to the other new one.

[1] http://wiki.diyfaq.org.uk/index.php?title=Cables#T.26E
[2] http://wiki.diyfaq.org.uk/index.php?...Cable_crimping

For information on acceptable workmanship on domestic work:

http://wiki.diyfaq.org.uk/index.php?..._workm anship


--
Cheers,

John.

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

On Sun, 02 Aug 2009 04:23:58 +0100, John Rumm wrote:

* How do I ensure that I'm not overloading the circuit?

Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!

Is it necessary to allow for PF with CFLs?
In the loft I have 7x11W CFLs, so 77W, but the PF is poor and so they're
about 145VA. The 30W CFL in another fitting is about 31VA - pity that the
lower wattage ones aren't as good.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

PeterC wrote:
On Sun, 02 Aug 2009 04:23:58 +0100, John Rumm wrote:

* How do I ensure that I'm not overloading the circuit?
Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!

Is it necessary to allow for PF with CFLs?

No, because according to the sizing guidelines the smallest power you
count is 100W - which is way more than a CFL even allowing for PF.

In the loft I have 7x11W CFLs, so 77W, but the PF is poor and so they're
about 145VA. The 30W CFL in another fitting is about 31VA - pity that the
lower wattage ones aren't as good.

You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for it.


--
Cheers,

John.

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

On Sun, 02 Aug 2009 15:41:00 +0100, John Rumm wrote:

PeterC wrote:
On Sun, 02 Aug 2009 04:23:58 +0100, John Rumm wrote:

* How do I ensure that I'm not overloading the circuit?
Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!

Is it necessary to allow for PF with CFLs?

No, because according to the sizing guidelines the smallest power you
count is 100W - which is way more than a CFL even allowing for PF.

In the loft I have 7x11W CFLs, so 77W, but the PF is poor and so they're
about 145VA. The 30W CFL in another fitting is about 31VA - pity that the
lower wattage ones aren't as good.

You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for it.

OK, thanks. It'd stand that but 100W lamps might melt something; I'd better
put in dome ally reflectors/heat shields. I woudn't put even a 40W GLS near
anything that might suffer from the heat, but I've seen several things
melted by over-powered lamps.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

PeterC wrote:
On Sun, 02 Aug 2009 15:41:00 +0100, John Rumm wrote:

PeterC wrote:
On Sun, 02 Aug 2009 04:23:58 +0100, John Rumm wrote:

* How do I ensure that I'm not overloading the circuit?
Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!
Is it necessary to allow for PF with CFLs?
No, because according to the sizing guidelines the smallest power you
count is 100W - which is way more than a CFL even allowing for PF.

In the loft I have 7x11W CFLs, so 77W, but the PF is poor and so they're
about 145VA. The 30W CFL in another fitting is about 31VA - pity that the
lower wattage ones aren't as good.
You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for it.

OK, thanks. It'd stand that but 100W lamps might melt something; I'd better
put in dome ally reflectors/heat shields. I woudn't put even a 40W GLS near
anything that might suffer from the heat, but I've seen several things
melted by over-powered lamps.

Many fittings are limited to 60W in reality.

--
Cheers,

John.

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

On Aug 2, 4:16*am, John Rumm wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
James Abley *wrote:

Rules - as in building regs, or laws of nature rules?

Both. The building regs include rules about where holes and notches can be
in order not to compromise the structural integrity. They have been quoted
in this NG in the past, but I can't quote the exact details offhand.

From:

http://wiki.diyfaq.org.uk/index.php?...llation#Joists

"To meet current building regulations, the hole does not want to be more
than 0.25 times the total joist height - so a 2" hole on a 8" joist is
about the limit. It should also not go closer to the end of the joist
than 1/4 of the span (so no nearer than 1m from the end of a 4m joist),
and no closer to the centre than 0.4 times the span."

http://wiki.diyfaq.org.uk/index.php?..._for_Beginners


NT

wrote:
On 2 Aug,
PeterC wrote:

On Sun, 02 Aug 2009 15:41:00 +0100, John Rumm wrote:

You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for
it.
OK, thanks. It'd stand that but 100W lamps might melt something; I'd better
put in dome ally reflectors/heat shields. I woudn't put even a 40W GLS near
anything that might suffer from the heat, but I've seen several things
melted by over-powered lamps.

Bbbbutt! you can no longer get GLS blubs greater than 60w (or so they say).

I haven't used a GLS lamp for years.

Most shops seem to have stocks of 100W ones again...


--
Cheers,

John.

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

On Mon, 03 Aug 2009 00:22:20 +0100, had this to say:

I haven't used a GLS lamp for years.

That doesn't mean that they aren't availabubble....

I bet you still hfr some Swan lamps though - in your torch, your oven,
your microwave, your sewing chamine - even your car!

--
Frank Erskine

On Sun, 02 Aug 2009 23:56:30 +0100, John Rumm wrote:

PeterC wrote:
On Sun, 02 Aug 2009 15:41:00 +0100, John Rumm wrote:

PeterC wrote:
On Sun, 02 Aug 2009 04:23:58 +0100, John Rumm wrote:

* How do I ensure that I'm not overloading the circuit?
Check the circuit breaker rating. Chances are its 6A. That limits the
total power to just under 1400W. To assess the size of of the existing
circuit then count 100W (or the actual rating if larger) for each light
position and just add em up. Sounds like you probably have over 1200W spare!
Is it necessary to allow for PF with CFLs?
No, because according to the sizing guidelines the smallest power you
count is 100W - which is way more than a CFL even allowing for PF.

In the loft I have 7x11W CFLs, so 77W, but the PF is poor and so they're
about 145VA. The 30W CFL in another fitting is about 31VA - pity that the
lower wattage ones aren't as good.
You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for it.

OK, thanks. It'd stand that but 100W lamps might melt something; I'd better
put in dome ally reflectors/heat shields. I woudn't put even a 40W GLS near
anything that might suffer from the heat, but I've seen several things
melted by over-powered lamps.

Many fittings are limited to 60W in reality.

Reality doesn't bother a lot of people - 100W in a 60W socket in a
spherical paper shade: there seems to be a burning smell. (Or the 'instant'
shower unit on 2.5!).
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

On Mon, 03 Aug 2009 00:22:20 +0100, wrote:

On 2 Aug,
PeterC wrote:

On Sun, 02 Aug 2009 15:41:00 +0100, John Rumm wrote:

You still treat the 7x fittings as 700W of load; since you could
realistically expect someone to install GLS bulbs and need to allow for
it.

OK, thanks. It'd stand that but 100W lamps might melt something; I'd better
put in dome ally reflectors/heat shields. I woudn't put even a 40W GLS near
anything that might suffer from the heat, but I've seen several things
melted by over-powered lamps.

Bbbbutt! you can no longer get GLS blubs greater than 60w (or so they say).

I haven't used a GLS lamp for years.

I have them only where I need light immediately but for a short time.
There's a 60W on the landing (for airing cupboard) but I recently put an
11W CFL in the hall as I have people staying and leave that light on if
they're late back; the CFL is brighter than the 60W bulb.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.