buenos días ingeniero Frederick Orloff, permítame realizo una consulta.
por favor me indica que sección del NEC 2020, especifica en que casos para los conductores de las acometidas y alimentadores, la ampaciyty de los conductores en cobre,( segun la tabla 310.16.) se selecciona a 75°C y a 90°C?
(tengo entendido que para circuitos ramales, la temperatura de selección del cable, para corrientes menores a 100 Amperios es de 60°C, (temperatura de operación del dispositivo de uso final, ejemplo tomacorrientes a 60 °C)
y para corrientes mayores a 100 A, el conductor se selecciona a 75°C.
pero para corrientes superiores a 300 A, no se si se puede seleccionar el conductor a 90 °C o en que casos se selecciona la Ampacity del conductor a 90°C.
Artículo 110-14(C). (1) Equipment Provisions. The determination of termination provisions of equipment shall be based on 110.14(C) (I)(a) or (C)(l)(b) . Unless the equipment is listed and marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.16 as appropriately modified by 310.1 2. (a) Termination provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, shall be used only for one of the following: ( 1) Conductors rated 60°C (l40°F) . (2) Conductors with higher temperature ratings, provided the ampacity of such conductors is determined based on the 60°C ( l 40°F) ampacity of the conductor size used. (3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors. ( 4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity. (b) Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following: (1) Conductors rated 75°C (l67°F) (2) Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors.
y claramente para mayores valores, e instalaciones que no sean interiores, por ejemplo tipo industrial, podrá emplear las tabla 310.18 para conductores con temperaturas de 150ºC, 200ºC ó 250ºC
310.18 Ampacities of Insulated Conductors in Raceway or Cable. The ampacities shall be as specified in Table 310.18 where all of the following conditions apply: (1) Conductors are rated 0 volts through 2000 volts. (2) Conductors are rated 150°C (302°F), 200°C (392°F), or 250°C ( 482°F). (3) Wiring is installed in a 40°C (104°F) ambient temperature. (4) There a re not more than three current-carrying conductors.
Todo la anterior para conductores en canalizaciones, si va a emplear bandejas portacables, entonces utilizará la tabla 310.19 para conductores con esas temperaturas.
buenos días ingeniero Frederick Orloff, permítame realizo una consulta.
ResponderBorrarpor favor me indica que sección del NEC 2020, especifica en que casos para los conductores de las acometidas y alimentadores, la ampaciyty de los conductores en cobre,( segun la tabla 310.16.) se selecciona a 75°C y a 90°C?
(tengo entendido que para circuitos ramales, la temperatura de selección del cable, para corrientes menores a 100 Amperios es de 60°C, (temperatura de operación del dispositivo de uso final, ejemplo tomacorrientes a 60 °C)
y para corrientes mayores a 100 A, el conductor se selecciona a 75°C.
pero para corrientes superiores a 300 A, no se si se puede seleccionar el conductor a 90 °C o en que casos se selecciona la Ampacity del conductor a 90°C.
muchas gracias profesor
Buen día....
BorrarArtículo 110-14(C).
(1) Equipment Provisions. The determination of termination
provisions of equipment shall be based on 110.14(C) (I)(a) or
(C)(l)(b) . Unless the equipment is listed and marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.16 as appropriately modified by 310.1 2.
(a) Termination provisions of equipment for circuits
rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, shall be used only for one of the following:
( 1) Conductors rated 60°C (l40°F) .
(2) Conductors with higher temperature ratings, provided
the ampacity of such conductors is determined based on
the 60°C ( l 40°F) ampacity of the conductor size used.
(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.
( 4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F)
ampacity.
(b) Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:
(1) Conductors rated 75°C (l67°F)
(2) Conductors with higher temperature ratings, provided
the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up
to their ampacity if the equipment is listed and identified
for use with such conductors.
y claramente para mayores valores, e instalaciones que no sean interiores, por ejemplo tipo industrial, podrá emplear las tabla 310.18 para conductores con temperaturas de 150ºC, 200ºC ó 250ºC
310.18 Ampacities of Insulated Conductors in Raceway or
Cable. The ampacities shall be as specified in Table 310.18
where all of the following conditions apply:
(1) Conductors are rated 0 volts through 2000 volts.
(2) Conductors are rated 150°C (302°F), 200°C (392°F), or
250°C ( 482°F).
(3) Wiring is installed in a 40°C (104°F) ambient temperature.
(4) There a re not more than three current-carrying conductors.
Todo la anterior para conductores en canalizaciones, si va a emplear bandejas portacables, entonces utilizará la tabla 310.19 para conductores con esas temperaturas.
Saludo.