Terminal Temperature Over 600Volts

[hill900505]

Hello everyone,
Is it correct to say if the equipment is rated over 600Volts, the conductor can be sized per 90 degree C regardless of the terminal rating. I am a little confused about NEC 110.40Conductors shall be permitted to be terminated based on the 90 °C (194 °F) temperature rating and ampacity as given in Table 310.60(C)(67) through Table 310.60(C)(86), unless otherwise identified.”
Also, NEC 110.40 is for voltage rating over 600 volts, however Table 310.60(c)(67)to(86) are for cables over 2000 volts, aren't we supposed to use 310.15.(B).(16) instead to size cables up to 2000volts?

Thanks everyone!

 

[GoldDigger]

I suspect that the code text is really stating a presumption that terminals rated for over 600V are assumed to be 90C rated, even if not marked, while terminals for under 600V are assumed to be rated for 75C unless explicitly marked for higher.
But I would be interested in seeing any CMP comments that are relevant.

 

[Smart $]

...
Also, NEC 110.40 is for voltage rating over 600 volts, however Table 310.60(c)(67)to(86) are for cables over 2000 volts, aren't we supposed to use 310.15.(B).(16) instead to size cables up to 2000volts?

You use Table 310.15(B)(16) to size cables on 600V and less nominal systems. The cable may be rated greater than 600V (2000V, for example).

Once your system's nominal voltage is greater than 600V you will be using cables rated not less than the 2001V you see in Table 310.60(C)(67) through Table 310.60(C)(86).

 

[hill900505]

You use Table 310.15(B)(16) to size cables on 600V and less nominal systems. The cable may be rated greater than 600V (2000V, for example).

Once your system's nominal voltage is greater than 600V you will be using cables rated not less than the 2001V you see in Table 310.60(C)(67) through Table 310.60(C)(86).

Thanks Smart $, also, are we supposed to size the conductor based on 90 degree C even if the terminal is only rated for 75 degree C for a system over 600 volts?

 

[Smart $]

Thanks Smart $, also, are we supposed to size the conductor based on 90 degree C even if the terminal is only rated for 75 degree C for a system over 600 volts?

If you look at Table 310.60(C)(67) through Table 310.60(C)(86) you'll see 90°C is the lowest temperature rating. What else can you use?