This is the things that engineers and site workers must
avoid when installing flush floor trunking (FFT); cable congested in FFT.
FFT normally consist of single, 2 compartments and 3 compartments
of internal trunking. These compartments are segregated between each other and
each compartment shall not be shared together.
Based on IEE Wiring Regulation, cabling in enclose enclosure
should comply with 40% space factor.
Meaning to say, all cables should only occupy only 60% of
overall internal dimension of FFT.
However, designer must consider the internal flyover inside
three compartments in FFT. This area can be considered as unused space in FFT.
Therefore, the actual usable space is much lesser than 60%.
Calculating the space factor without considering this unused
space will result congested cable in FFT (see figure below).
So..for all the designers, engineer as well as site
personnel, do take note and ensure your FFT are well organize.
