Cable Tray Cabling Question

[PSU Electrical]

Have a project we are designing that we have decided to go with Cable Tray for. Project is very process oriented with a lot of control cables and small motors/pumps on VFD's. Our controls/automation group has chosen two different types of Belden cable to use which is tray rated - Belden 29512 and Belden 1055A. The 1055A control cable is 600V rated and the 29512 is 1000V shielded VFD cable; the automation guys like it because it has a signal pair included they they take to the aux contact at the motor disconnect. Per NEC 392.20 (B), since the cable is not MC cable, do I need to have the barrier to separate the cables because they have different insulation ratings? If I do have the separation barrier in the tray, what happens when you come to an intersection and power and control is going in various directions and you have overlap of the cables?

 

[Julius Right]

In my opinion as according to NEC Art. 330.2 Definition.:
"Metal Clad Cable, Type MC. A factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of interlocking metal tape, or a SMOOTH or corrugated METALLIC SHEATH."
since both Belden cables are aluminum foil inner shielded [smooth metallic sheath] then may be considered MC cables. The may be run in the same cable tray without any separation.

 

[gadfly56]

In my opinion as according to NEC Art. 330.2 Definition.:
"Metal Clad Cable, Type MC. A factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of interlocking metal tape, or a SMOOTH or corrugated METALLIC SHEATH."
since both Belden cables are aluminum foil inner shielded [smooth metallic sheath] then may be considered MC cables. The may be run in the same cable tray without any separation.

If you look at the cut sheet for the cable, it's listed as RHW-2 and TC-ER, not MC. And how you could call foil "metal tape" or "metallic sheath" I don't understand, especially as they have to be the outer covering, not an inner layer.

 

[weressl]

Have a project we are designing that we have decided to go with Cable Tray for. Project is very process oriented with a lot of control cables and small motors/pumps on VFD's. Our controls/automation group has chosen two different types of Belden cable to use which is tray rated - Belden 29512 and Belden 1055A. The 1055A control cable is 600V rated and the 29512 is 1000V shielded VFD cable; the automation guys like it because it has a signal pair included they they take to the aux contact at the motor disconnect. Per NEC 392.20 (B), since the cable is not MC cable, do I need to have the barrier to separate the cables because they have different insulation ratings? If I do have the separation barrier in the tray, what happens when you come to an intersection and power and control is going in various directions and you have overlap of the cables?

Regardless of what Belden constructs all manufacturers clearly indicate that the power and control/signal wires should be routed in separate shielded cables and sometimes even a minimum physical distance is specified between the parallel running cables. Belden is not responsible for the proper functioning of the drive the drive Manufacturer is, so follow their rules.

 

[Julius Right]

I agree with you , gadfly56. Nevertheless, I doubt if the aluminum foil applied longitudinally and so creating a smooth surface it cannot be treated as MC[even if it is declared-by Manufacturer- as RHW].
I don't understand how 0.762 mm XLPE insulation is for 1000 V and 1.1938 mm PVC it is good only for 600 V.
UL-83 requires only 0.76 mm PVC for 600 V. By the way, IEC 60502-1 states up to 1 kV rated insulation only 0.8 mm PVC and 0.7 mm xlpe [for 1.5 sqrmm=approx. 16 awg].
In connection with "o/all pvc jacket": even MC declared cable is provided with a pvc jacket. See:
http://www.belden.com/products/industrialcable/ul-instrumentation-control-cable.cfm