cable tray MC and Cat5

[spsnyder]

Can MC and Cat5 (for data and digital control) share a cable tray as long as there is a vertical separation? The space above the ceiling is return air plenum so everything is plenum rated.

Also, weighting cable tray vs J-hooks. Schedule is pushing the design so wondering if it would be quicker to install cable tray and use it to route data and power to lights and lighting controllers and data, or if it would be quicker to install J-hooks every 4 ft for the CAT5 and EMT for the power. Thank for the help and advise.

 

[suemarkp]

See 800.133(A)(2), especially Exception 1 (I don't think anything in (A)(1) applies, and note that there is a code difference between the words cable and conductor -- most of the restrictions on separation deal with individual power conductors, not power cables).

Because you are using MC cable and not individual power conductors in that tray, I don't think you need any barriers or separation. I've had many people tell me that Romex (NM cable) and Cat5 must be 2" separated when running residential wiring. This section says no separation required when using NM, AC, MC or similar types of cabling.

Maintaining a separation may be prudent for other reasons. We usually put low voltage cables on one side of the cable tray and high power cable on the other to avoid interference.

 

[GoldDigger]

Data and control wiring is not as sensitive to 60Hz interference as voice and since CAT5 uses twisted pairs I would not worry much about separation unless very high currents or noisy voltages (back from non linear loads) were involved.
2" is a nice distance, but not required. For purely mechanical reasons I would not lay heavy cable on top of CAT5.
Especially if I planned on pulling on it later. :angel:

 

[tom baker]

Right no separation required. Same as running NM thru a bored hole with Cat 5. Code says OK, but industry practice does not recommend, but code does not care if your phone or computer has interference.

 

[Jon1980]

Back when I did Datacomm we kept a distance of 12" at minimum, Not always able to due to ceiling space. We also didn't run parallel with power conduits. This was Systimax standards. Most people wouldn't notice the interference anyway due to their computers aren't capable of running the speeds that they propose.



[h=3]Table A - Minimum Separation Distances[/h]

Conditions	Minimum Separation Distance
Greater Than	> 5kVa
Unshielded power lines or electrical equipment in proximity to SYSTIMAX cables in open or non metal containment. 610mm(24") Unshielded power lines or electrical equipment in proximity to SYSTIMAX cables in open or non metal containment. 610mm(24") Unshielded power lines or electrical equipment in proximity to SYSTIMAX cables in open or non metal containment.	610mm(24")
Unshielded power lines or electrical equipment in proximity to SYSTIMAX cables in a grounded metal conduit or fully enclosed trunking.	305mm(12")
Power lines enclosed in a grounded metal conduit (or equivalent shielding) in proximity to SYSTIMAX cables in open or non metal containment.(i.e. SWA power cables contained on traywork)	305mm(12")
Power lines enclosed in a grounded metal conduit (or equivalent shielding) in proximity to SYSTIMAX cables in a grounded metal conduit or fully enclosed trunking.	152mm(6")