Hi All,

Can anyone offer any advice on trunking spacing, ie. If there are x amount of cables in it currently, how can I work out out if I can fit additional ones in. (According to regs!)

The rule of thumb is 50%. If the trunking seems to be more than 50% full then I would use the cable and trunking factors in the OSG to work out if the trunking is sufficient for your needs or not. In practice however, the trunking is often rammed full.

We use 40% and thats quite standard in a few industries.

Hello All,

I am in the process of setting up/designing a new cable management system, can anyone tell me where I can find the regs for trunking requirements.
Thanks

There are no specific regulations - just that the cables shouldn't be damaged by installing them (and that you account for grouping in terms of cable current carrying capacity)

as a typical value, you should aim not to exceed more than 45% of the trunking internal area

So, if you have say a trunking that's 100 x 50mm and has a wall thickness of say 1.0mm then the GIA is 4802mm2.

45% of that is = 2161mm2

If we say that a 2.5mm2 single insulated conductor has a diameter of 4.0mm including insulation, then the overall area is 12.6mm2

So, you could install 2161/12.6 = 171 No x 2.5mm2 XLPE insulated singles into the trunking

Does that help

Regards

OMS

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Failure is always an option