Cable Riser

[fedail]

Hello,
could we use the same riser for medium voltage and low current. If it is Ok what is the space should be between them or any specification for the separate.

 

[malcolmsanford]

Fedail why are you using 2 different terminologies?

When you say Medium voltage are you referring to a voltage over 1000v AC/1500V DC so for example 11KV?

When you say low current do you mean a control circuit which may take milliamps?

 

[mogga]

I was wondering the same malky

 

[needasparks]

I think this is why.

http://www.electriciansforums.net/n...ns/50964-special-airport-system-engineer.html

 

[fedail]

Hello, thanks for your attention.
what i meant by low current is ultra low voltage like Fire Alarm Cable Or Network Cable.
i have only one shaft to use it but there is a medium voltage riser rising up there so i just want to decide can i use this shaft with low current and if it is OK what is requirements to do it

thanks in advance

 

[benji]

a lot would depend on how big the riser is and what containment is running in it

 

[fedail]

in general it is mean i can use the same shaft with them.
the riser size is 3.5 X .6 m and the midium voltage tray size is .6 X .2 m

 

[malcolmsanford]

Fedail do you have access to the BS 7671-2008 1st amendment ? If you have look at section 528 and 528.1 for circuits using band I, II and III.

In your case you need to look at the (vi) exceptions and I would imagine if you could follow exception (i)

"Every cable or conductor is insulated for the highest voltage present"

I have just installed miles of Cat 5e cable here from Draka Cables and they all run on the same cable tray as my LV transmissions as the Cat cable is rated for 1000v.

If though you have transmission for over a 1000v then you may have to either run it in a separate trunking, or if it has to go on the same cable tray using an insulation medium or complete separated by distance.

 

[needasparks]

I would think in an airport setup, separated would mean separated and not be run on the same tray as malc says, but things may be different in the middle east.

 

[telectrix]

if you have room to fit a separate tray for the elv, as it seems you have a 200mm tray in a 600mm riser, then that's the ideal way forward.

 

[lamb]

His riser is 3.5m wide and the HV ladder rack is 600mm wide, plenty of space left for basket runs then for F/A, structured cabling etc.