Single Conductor and Cable Tray Options

[JeremyO]

I am requesting help on an application. The company I work for manufactures electrical equipment buildings for the utility industry. We often have a termination cabinet for external wiring and a cable tray mounted over relay panels. We commonly use multi-conductor cable for power, controls, and alarms using the cable tray as a means of interconnection between equipment. If a single conductor is required, conduit and THHN is used as long as it doen't hit the cable tray. Should the single conductor need to go thru the tray, a junction box is used and a conversion to multi-conductor cable is created.

My ultimate goal is to find a conductor or wiring method that will allow me to wire most all the circuits in our building using an individual conductor and wire labels for to-from destination details. So far, all I can find per article 392 in the NEC is that the largest single-conductor cable allowed in a cable tray is 1/0 or bigger and must be rated for tray cable. I would like to find a conductor type, wiring method, or add-on product that would allow me to run single conductor 10ga and below anywhere in the building I wish to make any termination I desire. I would entertain any methods necessary to permit single conductor. The preferred wire type I would like to use is SIS or any commonly stocked and cost-effective solution acceptable for this application. Any suggestions? Any NEC code backup details would also be appreciated.

 

[tom baker]

Can you use multi conductor tray cable in a raceway to outlets?
Or use pvc jacketed mc cable?

 

[JeremyO]

Thank you for the reply. I am trying to get away from using multi-conductor cable if possible. I would prefer to pull single conductors in each case even if I need to change the wiring method applied (ex tray, conduit, raceway, etc.). An example of what we currently do and the equipment and paths in the building are as follows:

- Termination Cabinet to Relay Panels via Cable Tray using multi-conductor cable.
- Relay Panels to Relay Panels uses SIS wire mounted in Panduit or built-in channel in relay panels.
- AC Panels to Lighting/Receptacles via Conduit, Cable Tray, and/or metal raceway. Uses multi-conductor cable on tray or THHN in conduit.
- Alarm Circuits to Relay Panels via Conduit and Cable Tray, again using multi-conductor or THHN depending on installation.

I am currently using a mixture of multi-conductor cables when crossing the cable tray and THHN wire in conduit to make these runs. I am looking for a solution that would allow me to use single conductor wire in place of multi-conductor cable. For example, is there a product that would allow me to pull all single conductor wires to every component in the building without the need for multi-conductor cable?