cable tray question
- Thread starter aaatraker
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bdarnell
Senior Member
- Location
- Indianapolis, IN
- Occupation
- Retired Engineer
Are you asking how to size cable tray for fill or rigid metal conduit for fill ? Your post seemed to ask two questions. See Article 392 for tray fill tables, and yes, you do have to apply derating in certain conditions.
Edit: I see what you are asking now. You are installing tray cable in RMC. What type of cable and is it a multiconductor type ?
Edit: I see what you are asking now. You are installing tray cable in RMC. What type of cable and is it a multiconductor type ?
Last edited:
kingpb
Senior Member
- Location
- SE USA as far as you can go
- Occupation
- Engineer, Registered
It appears to be a multi-conductor with 3-#1 AWG, & 1-#6 AWG Gnd.
The important issue is, what is the maximum outside diameter of the cable? That will determine conduit size. The overall cross sectional area of the multi-conductor cable cannot exceed 40% of the interior cross sectional area of the conduit.
For three current carrying conductors, there is not an ampacity derating, unless you are going to exceed the ambient temperature.
The important issue is, what is the maximum outside diameter of the cable? That will determine conduit size. The overall cross sectional area of the multi-conductor cable cannot exceed 40% of the interior cross sectional area of the conduit.
For three current carrying conductors, there is not an ampacity derating, unless you are going to exceed the ambient temperature.
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