Temperature when installing cable ladders 20 ºc calculations temperature differential 40 ºc expansion of stainless steel for this temperature range 0 69 mm m expansion coupler gap when installing including safety factor 15 0 mm.
Cable ladder support span calculation.
To ensure adequate support accessories should be supported locally.
The span length from the support.
A typical multi span cable ladder or cable tray installation behaves largely as a continuous beam.
The quick tray wire mesh cable tray fill table below shows the number of cables and the load in lbf lineal foot developed by typical 4 pair and 6 pair cable weighing 20 lb kft and 40 lb kft respectively while this table is a useful guide actual loads must be calculated using the cable specified.
However in practice a run must contain joints and it can also never be of infinite length so it is important to appreciate how its characteristics vary from span to span and how these.
L intermediate span f deflection 1 100 of the intermediate span max s splice location.
Quick tray wire mesh cable tray fill table at 50.
6 cable ladder and cable tray systems including channel support systems and other associated supports definitions and abbreviations accessory component used for a supplementary function e g.
Unistrut s load testing is in accordance with cei iec 61537 2001.
In practical terms this covers continuous multi span installations evenly loaded along the length of and across the full width of the tray.
Unistrut s load and deflection figures are in accordance with cei iec 61537 2001 with the characteristic deflection of unistrut cable ladder limited to span 100.
This classification is based on the working load the total weight of the cables and the support span the distance between supports.
Cable tray is a mechanical support system for cables and raceways.
610mm of a splice on straight sections and the span between supports should not exceed the length of tray.
Hazardous voltages in electrical equipment can cause severe personal injury or death.
To join two components together clamp or fix to walls ceilings or other supports covers and cable retainers associated supports bespoke supports for cable tray and cable ladder other than bs 6946 channel.
And load figures inclusive of a safety factor of 1 7.
Cable load working load the cable load or the working load is the total weight of the cables to be placed in the tray.
Supports should be placed within 24 in.
Using cable trays as walkways can cause personal injury and also damage cable tray and installed cables.
The nema classes are based on cable loads of 50 75 and 100 per lineal foot.
The greater the number of spans the closer the similarity.
Support points are often trapezes suspended from threaded rod cantilever brackets or other strut systems.
Expansion splice plates.
Do not use a cable tray as a walkway ladder or support for people.
