Planning
a Fibre Optic System
This
section will take you through the design process for most fibre optic
applications. If you need any further help or perhaps you have a non
standard requirement then our Technical Department would be pleased
to help.
Planning
Stage One
Design Parameters and Cost
1. Performance
Decide
exactly what you need to achieve with the equipment. Fibre Optics can
be used in a wide range of applications and the photometric data in
this catalogue should help you to choose the right combination of products.
2. Budget
Having
made a rough selection of products, check the cost against the budget.
Fibre Optic systems have become cheaper over the past five years but
they are still generally more expensive than conventional luminaires
for downlighting/accent applications. Sparkle ceilings and other decorative
applications can usually show cost savings against conventional tungsten
halogen systems.
Planning
Stage Two
Simple Rules of Design
1. Harness
Lengths
Keep
all harness lengths for end lit applications as short as possible. Try
to keep tail lengths less than 10 metres and no more than 2 metres between
shortest and longest tails. PMMA fibre has considerably lower transmission
losses than most glass fibres and longer tail lengths can be used. For
exterior paver installations, 30 metres plus is possible.
2. Lateral
Fibre Maximum Lengths
For
lateral side lit fibre the maximum length should be kept below 30 metres
with light coming from both ends. Usually this means a lightprojector
at each
end, although the fibre can return in a loop to the same lightprojector.
In some installations up to 45 metres can be used but with some fall
off toward the centre. The appearance of lengths more than 30m should
always be approved by the customer.
3. Lightprojector
Choice
Most
installations work well with 150w metal halide. These projectors produce
good luminance on lateral fibre and are also ideal for cabinet/display
lighting.
For maximum
output the 400w HTI lightprojector is ideal although the shorter lamp
life (1,500 hours) must be compared to the life of the metal halide
units (6 to 8,000 hours).
Low
level lighting (critical museum displays or sparkle ceilings) can make
good use of the 100w halogen lightprojectors.