I've browsed the group for a while, and am looking for advice on the
use (or misuse) of connector strips in domestic lighting. We recently
had a flat rewired and various types of LV lighting put in throughout.
In most cases the electrician used junction boxes to wire the prewrired
transformers onto the lighting circuits, with those being fed from
about 25 dimmers in several DIN boxes located mostly in the loft.
Generally the guys would make a hole in the ceiling, wire the JB, and
then feed the JB, transformer and finally the fitting into the ceiling.
However, some fittings are small and a JB wouldn't go through the hole,
and access wasn't necessarily possible from above. In this case they
used 3 poles from a suitably rated connector strip, wrapped the strip
in tape for insulation, and finally fed everything through the hole as
before. Although fine for insulation, does this contravene the regs,
and if so, how should one wire this to comply given the access
restrictions from above/below?

Also, with regards to access of junction boxes. In this property,
almost all JB's are accessible via the loft, but a few are beneath a
floor above. Of those, some can be popped down if the light fitting is
removed, but if this isn't possible, is it mandatory that permanent
access be provided somehow from above? This would require a hatch
somewhere, but wouldn't be great in some types of flooring, and could
be impossible if the floor above was tiled, had underfloor heating etc.
Longer cable runs to JB's that are located at an accessible point
should be possible in that case (but maybe not always), but with even
more complicated and obscure wiring as a result. Using a connector
strip would then seem the better solution as bringing a light down from
the ceiling would be possible, albeit not ideal, and would give more
logical and straightforward wiring.

Advice, ideas and rules and regs welcome.

On 1 Mar 2005 03:05:00 -0800, wrote:


However, some fittings are small and a JB wouldn't go through the hole,
and access wasn't necessarily possible from above. In this case they
used 3 poles from a suitably rated connector strip, wrapped the strip
in tape for insulation, and finally fed everything through the hole as
before. Although fine for insulation, does this contravene the regs,
and if so, how should one wire this to comply given the access
restrictions from above/below?

Presuming, for a moment, that the wiring you're talking about is
normal low voltage - that is, 230VAC, then connector strip isn't
illegal, just dodgy, if it's only wrapped up in insulation tape.

If you're talking about the Extra low voltage - e.g. 12V secondary
side of the transformers, then only ceramic connectors should be used,
because of the heat.

You can easily obtain small inline connector boxes, which essentially
are plastic or heat resistant connecting block within an inline case.
These are generally only an inch and a bit across by about two inches
long - sorry, about twenty mil wide by about fifty mil long. Far
neater, much safer.

Insulating tape doesn't have many heat resisting properties. Nor does
plastic strip connector.

Other than that, feeding the connector through the fitting aperture in
the ceiling is OK, so long as it is connected safely, for heat AND
power.

Also, with regards to access of junction boxes. In this property,
almost all JB's are accessible via the loft, but a few are beneath a
floor above. Of those, some can be popped down if the light fitting is
removed, but if this isn't possible, is it mandatory that permanent
access be provided somehow from above?

Nope - see above.

This would require a hatch
somewhere, but wouldn't be great in some types of flooring, and could
be impossible if the floor above was tiled, had underfloor heating etc.
Longer cable runs to JB's that are located at an accessible point
should be possible in that case (but maybe not always), but with even
more complicated and obscure wiring as a result.

Generally, it is a question of cable size and rating.

Bear in mind that on the primary side, the current is lower although
the voltage is higher - the reverse is true on the secondary.

It isn't uncommon to run ULV lighting in 4mm T&E on the secondary,
back to a central JB, making off the fitting in ceramic blocks at the
fitting end.

Using a connector
strip would then seem the better solution as bringing a light down from
the ceiling would be possible, albeit not ideal, and would give more
logical and straightforward wiring.

Yes, so long as it is the correct connector for the job.

wrote:

Generally the guys would make a hole in the ceiling, wire the JB, and
then feed the JB, transformer and finally the fitting into the ceiling.
However, some fittings are small and a JB wouldn't go through the hole,
and access wasn't necessarily possible from above.

Don't ask me about regs - there are plenty of folk here far more
qualified to answer you than me - but I can tell you that dinky little
junction boxes are available which are ideal for the purpose. See:
http://www.tlc-direct.co.uk/Products/ASJ201.html
These are smaller in diameter than most, if not all, 12V downlighters,
and will pass through the hole in the plasterboard. They don't seem to
be particularly well known. Neither Screwfix nor Toolstation stock them.

David

Lobster wrote in message ...
wrote:

Generally the guys would make a hole in the ceiling, wire the JB, and
then feed the JB, transformer and finally the fitting into the ceiling.
However, some fittings are small and a JB wouldn't go through the hole,
and access wasn't necessarily possible from above.

Don't ask me about regs - there are plenty of folk here far more
qualified to answer you than me - but I can tell you that dinky little
junction boxes are available which are ideal for the purpose. See:
http://www.tlc-direct.co.uk/Products/ASJ201.html
These are smaller in diameter than most, if not all, 12V downlighters,
and will pass through the hole in the plasterboard. They don't seem to
be particularly well known. Neither Screwfix nor Toolstation stock them.

Thanks David. Some of those are used, and you're right about them, but
we have some some lights with even smaller holes, and no JB's would
fit for those. Over 2K spent at Mr Resistor bought some good (and some
less good) lighting, but lots of hastle one way and another as well.