motor phase conductors

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something beyond 430.22 ??
Seems like FLA per TABLES X 1.25% covers 95% of installations.
 
You leave the discussion pretty wide open with that.

Why don't you start by reading through art 210 and 430 and then ask more specific questions about things you do not understand?
 
cbcm18 said:
which temperature rateing do we use for amp load
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I'm not totally sure what you are asking but I'll give it a shot.

110.14(C)(1) says that if rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors then the terminations are rated 60oC and if over 100 amps or larger than 1 AWG conductors then terminations are rated 75oC, unless equipment is otherwise marked.

If you are dealing with new equipment and new conductors commonly available today most equipment has terminals rated for 75C. Older equipment may only have 60oC terminals so you have to watch for that. Also with new conductors today the insulation is generally 90oC but older conductors may only have been 60oC or 75oC so you have to pay attention when dealing with older installations.
If you have high ambient temperature situations then you need to adjust ampacity for that - this is all same thing as sizing conductors in general and not just motors, the only thing special about motors is determining minimum ampacity required for a particular motor, beyond that ampacity adjustments are same as for other circuits.

Minimum ampacity is generally 125% of motor full load current (like was said probably about 95% of all installations), this full load current comes from tables in Part XIV of art 430, for motors not listed in those tables you generally use nameplate full load current. Those tables will have most every standard NEMA designed motor included, it is special purpose motors that may not be in the tables.
 
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