Cable Tray Load Capacity Explained

Cables are heavy, steel containment is heavy, even the fixing brackets are heavy! How do you know that your installed wiring system won't collapse and fall off the wall or ceiling?

There's lots of information out there about not overfilling cable tray, trunking and conduit, but this is from an overcrowding point of view, not from a weight point of view.

So with help from the good people at @MarshallTufflex we've dived into the data and calculations to demonstrate how you can be sure that your wiring system will stay safely where it belongs.

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Time Stamps ⏱
00:00 Will containment take the weight of what's in it?
00:27 Installs can weigh a serious amount
01:00 We must refer to the manufacturers instructions
01:23 How much weight can a 300mm cable tray take?
01:57 Calculating how many cables we can place on our tray
04:15 Choosing the correct cable tray
04:50 Calculating the maximum number of cables a tray can carry
05:55 How to support the tray itself
06:10 Calculating how much weight the support can take
07:40 Choosing and spacing wall brackets
08:31 It's normal for brackets to deform when in use
09:20 Validate your learning
09:33 How to make sure containment doesn't collapse prematurely
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#trunking #conduit #containment

[michaelcostello]

Very helpful video for an apprentice or electrician . Thank you

[tombrown]

I've always worked on the assumption max loading per m was based on supports every meter. Spacing supports at 1.2 means you lower the recommended max loading weight.

[stevecraft]

I installed some 300mm tray recently, but shortly after installation it was buried behind air handling units and associated pipework so the only way to pull cables along it was to crawl along it. I think it's strong enough...

[mathiasjacobsen]

When in installing several trays at 3 m length, i use 3 supports. 1 in the middle, 1 at each end spaced 0.5 m from end cable tray. A bit more rigid than using 2 supports.

[leestorey]

What about manufactured brackets like using unistrut and studs, because everyone on site says it must be space 1200mm but no-one can show me where it come from

[robbiedix]

I have never installed cable tray in an industrial environment, I normally install ladder rack.

[andrewrangecroft]

Been on a site in finland, all the tray work was bending from overload. Support distance were to great.

[averagedev]

I went a different route, wait for it to fall, and then duouble the support there. Not the best but its faster enought

[lewisbrand]

A cable tray is a heat radiator, not just something to strap heat producing cables ad infinitum to

[tonywatson]

Everyone has to shown and told EVERYTHING these days....im 75 ...i can look at stuff, and deduce ...nah. that wont do ...i can see angels and problams...young people are thick

[johnwarwick]

Don’t forget to allow for the odd electrician crawling about on there as well when you get up yo the wider tray size.