Cable routing in Commercial unit

[cosinephi]

Anyone care to offer an opinion...

I`ve a job involving installing cabling for various circuits in a new commercial unit, which is split between the office/reception/facilities area & a workshop/warehouse space (much the larger part)

As the vast majority of the circuits run from the DB (in the workshop) along the perimeter of the newly formed office space studwork, getting the necessary cabling for the multitude of sockets & panel heating is proving something of a sticking point. As there`s gonna be a fair bit of thermal insulation goin in the ceiling void, i was looking to minimise running anything but lighting cables in there, & suggested to the client the installation of a run of 150mm wire basket, or tray, around the perimeter (approx 22m run) would prove the best solution for both the now - avoiding serious de-rating of cables - & for future expansion.

Looking to save costs, he`s come back to me & asked why can`t i use the `u-channel` which sits above the blockwork & supplies an anchoring point for the steel/cladding upper fabric of the structure.

As it already contains BTs cabling for phones & BB, & its hardly without protrusions (bolts/brackets) i said i`d prefer to do it my way...to which he`s replied that on all the other installs he`s overseen, the sparks had no issue running everything in the `u-channel`

He`s obviously of the view i`m being too finicky about it.

What do others think?

 

[Dan007]

Not seen that u channel stuff your talking about but wouldn't you have an issue with segregation of circuits i.e band I & II?

 

[cosinephi]

Certainly. But in fairness, a non-conducting pane between Band I & II would be easily achieved - YT1 pvc trunking much cheaper than steel tray/basket.

As to the `U-channel` - thats just a generally used term for the galv steel hockeystick-shaped former that sits atop the blockwork, & as it mates to the inner surface of the cladding, they collectively make an impromptu duct or channel...pretty much a standard feature of cladded commercial units.

Thing is, it more often than not WAS used to carry cabling along the perimeter of such buildings. Especially the basic initial installs ahead of the tenant developing the space. In most cases, it`d be left in, & quite often added to. Come across it on PIRs all the time with JBs & every kind of crap lying on top.

I`ve always viewed it a little like running cables in cavities - twas never a great practice, but was seen as an acceptable method for donkeys.

 

[Dan007]

Is there not a distance factor of 50mm or is this if your not using segregation? Anyways as long as this is achieved I don't see the problem with using the u-channel. Maybe ladder or tray would be better practice but as long as there are no sharp protrusions in the channel which may cause damage to the cable sheath and maybe even the use of hi-tuff cable for additional mechanical protection or SY cable rather than PVC/PVC? Without seeing it's hard to make a educated opinion but you sound as though you have good enough judgement and experience to make the call. Convincing a penny pinching customer maybe another thing though! Good luck

 

[cosinephi]

Thanks for the thoughts there Dan.

Truth is, it urks me that due to economics we`re constantly being pressured into cutting corners & lowering our standards.

For the same reason (