Ampacity Based Table 310.16

[mbrooke]

Should the wire sizes in table 310.16 be adjusted to reflect the actual listed table ampacity in the NEC's current table 310.16 instead of rounded current ratings?


When cable assemblies and conduit over the years were tested in contact with thermal insulation, the temperature of the conductors varied significantly for their rated current carrying capacity with all controls being identical. For example, 14 gauge wire comes around to 18.75 amps at 60*C, 12 gauge wire only around 21 amps at 60*C and 10 gauge around 27 amps at 60*C. But #1 is good for 140 amps, 4/0 248 amps at 75*C, ect.

Revised Table 310.16:

 

[mbrooke]

De-rating table:

 

[romex jockey]

Some NRTL testing methods were posted here a while ago.

IIRC, they'd group and run NM @ peak ampacites.

the then agreed 'safe ampacities' are further confronted ,examples such as 334.80 , 310.15(B)(3)(a)

the reality being a double derating scenario ,for what rarely if ever occurs in the 1st place

~RJ~

 

[mbrooke]

Some NRTL testing methods were posted here a while ago.

IIRC, they'd group and run NM @ peak ampacites.

the then agreed 'safe ampacities' are further confronted ,examples such as 334.80 , 310.15(B)(3)(a)

the reality being a double derating scenario ,for what rarely if ever occurs in the 1st place

~RJ~

Do you have them by chance?

 

[romex jockey]

I wish i did MBrooke...:happysad:~RJ~

 

[mbrooke]

I wish i did MBrooke...:happysad:~RJ~

Its alright, though UL does seem interested in standardization to some degree:

https://62368-ul-solutions.com/engineers/clause-6-of-iec-62368-1-flammability-requirements/

 

[romex jockey]

Its alright, though UL does seem interested in standardization to some degree:

https://62368-ul-solutions.com/engineers/clause-6-of-iec-62368-1-flammability-requirements/

Clause 6 of IEC 62368-1 requires most wiring & cable to comply with the flammability requirements in IEC 60332-1-2, IEC 60332-1-3, IEC 60332-2-2, or IEC/TS 60695-11-2.

always a cornucopia of standards ....:roll:

did i tell you about the mattress i threw in the firepit?

i figured it'd just smoke a while......turns out it went up like a roman candle

maybe i should't have ripped the label off....:lol: ~RJ~

 

[mbrooke]

always a cornucopia of standards ....:roll:

did i tell you about the mattress i threw in the firepit?

i figured it'd just smoke a while......turns out it went up like a roman candle

maybe i should't have ripped the label off....:lol: ~RJ~

Flammability labels are often forged, trust me on this