motor termination temperatures

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bh

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Since the wire size for a load has to consider termination temperature what is the termination temperature for the T lead connections of a 30 HP, 460 volt, 3 phase motor? I believe most motor starters for that size motor are rated for 75 degrees C
 

jim dungar

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PE (Retired) - Power Systems
Re: motor termination temperatures

Little know and often ignored fact:

Per NEMA Standards Publication ICS 2.4-1989 (R2000)
4.5 TERMINAL TEMPERATURE RISE
Traditional NEMA starters and contactors are designed for use with 60?C temperature wire with a corresponding allowable 50?C terminal temperature rise.

Typically, IEC starters and contactors, and those NEMA starters and contactors so marked, require 75?C temperature wire with a corresponding 65?C allowable terminal temperature rise when UL Listed.
Controller temperature rise requires consideration when an enclosure is selected.

When one type of controller is replaced with the other, the existing wire size, and wire temperature rating, need to be considered.
 
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