D!NNy
Senior Member
- Location
- San Luis Obispo
Hello,
can someone help in understanding these tables: Currently i am sizing conductors from a switchgear to motor via cable tray for 500HP motor of 549.4FLA.
Based 110.14 (C) (1) (b), for temperature Limitations: For the circuits over 100A conductor size to be based on 75 Deg C. using table 310.15(B)(16) as mentioned in 110.14 (C) (1).
But In article 392.80 (2) (d) Ampacity of conductors to be selected based on the table 310.15(B)(20) which has very high ampacity when compared to the 310.15(B)(16).
Thanks for the help in advance.
can someone help in understanding these tables: Currently i am sizing conductors from a switchgear to motor via cable tray for 500HP motor of 549.4FLA.
Based 110.14 (C) (1) (b), for temperature Limitations: For the circuits over 100A conductor size to be based on 75 Deg C. using table 310.15(B)(16) as mentioned in 110.14 (C) (1).
But In article 392.80 (2) (d) Ampacity of conductors to be selected based on the table 310.15(B)(20) which has very high ampacity when compared to the 310.15(B)(16).
- But none of the manufacturer provide the ampacities for the cable tray rated cables to match with 310.15(B)(20)?
- southwire Cable tray rated cable link http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet67
- Example 500MCM has 380 amp per 310.15(B)(16) and 496 amps per 310.15(B)(20) at 30 DEg C and 40 Deg C temperatures respectively.
- Why the ampcities of these two tables are having huge difference in ampacities? is it just because of the ventilation?
Thanks for the help in advance.