Phneumatics and cables

[Spark plug]

Just a quick one, without going into too Mutch detail, is it acceptable to install pneumatic pipe inside a steel trunking with cables?

 

[premmington]

I always separate mains voltage cables from control voltage cables (low voltage). I never share cable enclosures with water or gas pipes!

But air pipes? Good question. My initial thought would be no! If they were metal air pipes, they must be PE earth bonded!

I keep thinking no to this! But hard plastic push fit air pipes come to mind!

Good question!

I have no defined answer... But I have seen open tray work in factory with hard plastic air and electric cables attached to it!

 

[shedfull]

5.16 Cables segregated / separated from non-electrical services (528.3)

I wouldn't have thought you could run an air supply in trunking taking this reg in mind

 

[daleyd]

We used to run pneumatic tubing for metso actuators in the same trunking as the wiring (24 volt and thermocouple/signal wiring) and it never caused any issues. The machines were ce marked so I assume it was all ok.

The only thing we used to do as mentioned before is to run the mains stuff separately.

 

[shedfull]

I thought the op was meaning a Mains installation.

I wouldn't run anything in a trunking system other than electric cables, a compresed air supply should be bonded to earth, if that's not been done properly you could be introducing an earthy conductor.

24v stuff? dunno

edit 'cos linkk was bllks

 

[daleyd]

It's in metal trunking, so the same should apply to that? Ours was run in plastic tubing, when I say mains was run separately I meant 415 supply for big 3 phase motors, there was also some small power 240 volt wires in the same trunking as the air supply for servo motor supply and remote power supplies etc but nothing taking a lot of current

 

[Spark plug]

Ok so it's looking like its a no no, its a mains installation and I'm using the hard plastic push fit type pipe.

It fairly common to mix them up within machenery a good example would be the hearing type plugs ware it's common to fit both pneumatics and electrical connections. But the wireing regulations does not cover machenery (yet).

 

[daleyd]

If it's plastic pipe and non conductive I would have thought it should be ok? I haven't done 17th edition so I can't help you there, but there's probably some section in there about it.

I seem to remember there being something about conductive pipes etc but not sure if it would apply to plastic?

 

[premmington]

If it's plastic pipe and non conductive I would have thought it should be ok? I haven't done 17th edition so I can't help you there, but there's probably some section in there about it.

I seem to remember there being something about conductive pipes etc but not sure if it would apply to plastic?

This was my initial feeling. But air pipes can carry water! So it is a definate no from me!

 

[daleyd]

This was my initial feeling. But air pipes can carry water! So it is a definate no from me!

The pipe itself is non conductive though, I don't think it matters what it's carrying inside? (I'm not sure, ie I don't have the info I hand but I thought this was the case)

 

[Robotstar5]

The section on ducts & cable trays in EN60204-1 (machine building) has this...

In order to prevent confusion of conduits with oil, air, or water piping, it is recommended that
the conduits be either physically separated or suitably identified.

 

[rtbcomp]

Compressed air pipes may introduce heat into the conduit which would be undesirable. If there was an electrical fire in the conduit this could melt plastic pipe and the compressed air would encourage combustion.

 

[premmington]

Compressed air pipes may introduce heat into the conduit which would be undesirable. If there was an electrical fire in the conduit this could melt plastic pipe and the compressed air would encourage combustion.

Very true!

 

[Spark plug]

Ok so I'm working on a means of fixing the pipe to the outside of the trunking, any ideas chaps?

 

[daleyd]

Can you get dividers for the inside of the trunking? I've seen those before.

What size pipe are you using?

 

[Spark plug]

It 10mm pipe but there's only one witch makes installing dividers a bit ott. I am thinking about p clips on the outside.

 

[daleyd]

It 10mm pipe but there's only one witch makes installing dividers a bit ott. I am thinking about p clips on the outside.

Yeah, that would probably be the easiest if you don't want it in the trunking. I've also seen small saddles used as well which clip over the top which look quite neat, the screw is hidden under the pipe so looks a bit cleaner than p clips.

(Though I still haven't seen anything which says you can't run it in the trunking, just that it needs to be properly marked and non conductive.)

 

[Robotstar5]

Sticky cable tie pads? - link

 

[500e]

Never made them stick for any time especially if there is heat involved, "inventions of the devil

"

 

[Spark plug]

Sticky cable tie pads? - link

This room can gets very hot even with air con so sticker ones will probably fall off