I.S. and Power Cabling Segregation

[Anode]

Hi,
My attempts to find an answer on the net has not been successful. Any assistance would be appreciated.
What I am after is:

What is the minimum distance required between an intrinsically safe/instrumentation cable and 440V AC power cable. Also what should be the minimum spacing between a 6.6kV power cable and the other two?

Thank you.

 

[RajT]

Industry practice allows for a separation of 300mm in all cases stated.

 

[RajT]

There is no hard and fast rule on spacing and its more of a question of choice and judgement, however practices in the petrochem industry allow for 150mm spacing between all instrumentation cabling and LV power cables (ie upto 100V) and 300mm between instrumentation cables and HV (ie above 1kV)cables. The practice does specify the use of screened instrumentation cables throughout.

 

[Baldor]

I have been required to to have a minimum of 500mm air gap between IS and non-IS wiring. However, it was allowable to have a solid barrier with an equal amount of creepage distance between them. This was a North Sea application, DNV specs I think.

 

[resqcapt19]

The NEC says:
"504.30 Separation of Intrinsically Safe Conductors.
(A) From Nonintrinsically Safe Circuit Conductors.
(1) Open Wiring. Conductors and cables of intrinsically safe circuits not in raceways or cable trays shall be separated at least 50 mm (2 in.) and secured from conductors and cables of any nonintrinsically safe circuits.
Exception: Where either (1) all of the intrinsically safe circuit conductors are in Type MI or MC cables or (2) all of the nonintrinsically safe circuit conductors are in raceways or Type MI or MC cables where the sheathing or cladding is capable of carrying fault current to ground."

Don