EMF and GRP cable tray barrier

[Scotsinst]

We are running 24V Analog cable in the same GRP cable tray as 24VDC solenoid cable, separated by a GRP barrier.
Is there an issue with EMF through the barrier considering both are DC cables? (I assume when the solenoid is energized/de-energized) Should the barrier be 316 sst or similar?
The dielectric strength of the barrier is 170 volts/mil. minimum.
I'd appreciate any guidance.

 

[ScottyUK]

Are the cables armoured or screened? The dielectric strength doesn't matter in this case, but it is essentially transparent to HF capacitively coupled noise. If the analog cable is screened you shouldn't have too many problems.


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I don't suffer from insanity. I enjoy it...

 

[Ashereng]

We have run 24V analog cables (Tec Armor) and 24V discrete (multi-core conductors), including for solenoid, in the same tray on previous jobs.

I am not electrical, but the design was by our electrical group. Everything seems to work well enough.



"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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[Scotsinst]

Thanks Scotty, Ashereng
The analog cables are armoured and screened. The digital cables are collectively screened but the individual pairs are not screened.

 

[waross]

Hi Scotsinst;
As 316 sst is nonmagnetic, it would be mediocre at reducing interference. It's fairly high resistance would not be an asset either. It would be good for physical protection in the event of an arcing power cable. Magnetic materials are much more effective than non magnetic materials at reducing induced interference.
respectfully

 

[ScottyUK]

Hi waross,

I don't think the problem will be magnetic interference, more likely capacitive coupling. Any earthed metallic structure serves to act as a grounded electrode between the 'plates' of the parasitic capacitor formed between the source of the interfering signal and the affected circuit, thus shunting the interfering signal to ground. On the off chance that the problem is magnetically coupled, the best solution is separation. After that we head off into the expensive world of mu-metal shielding and other exotica. I've never seen such shielding applied outside of electronic assemblies - certainly not out on cable tray! It would be cheaper to put in a parallel tray route than provide that level of shielding.

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I don't suffer from insanity. I enjoy it...