Electrical Engineer

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raymond canzoneri

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I want information as to which year did the NEC enlist applying adjustment factors for a certain number of current carrying conductors in a raceway.
 
1940 is the earliest I can find it.

Chapter 10, Table 1, Allowable Current-Carrying Capacites of Conductors, In Amperes, Note 5.
 
raymond canzoneri said:
I want information as to which year did the NEC enlist applying adjustment factors for a certain number of current carrying conductors in a raceway.
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The knowledge existed before the NEC was published. It is based on principal of behavior of electricity. (Resistance exist, resistance will produce heat, there is a balance between the safety, wire size, insulation cost, insulation life.)
 
weressl said:
The knowledge existed before the NEC was published. It is based on principal of behavior of electricity. (Resistance exist, resistance will produce heat, there is a balance between the safety, wire size, insulation cost, insulation life.)
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Maybe it took so long to get adopted because not many conductors were crammed into one pipe back in the day. usually it was one pipe, one or two circuits. That's all that was needed. I've seen a lot of old stuff, but never 22 wires in one raceway that I can date to The Great Depression.



The 1930's Great Depression, that is.:grin:
 
Raymond Canzoneri, Electrical Engineer

Raymond Canzoneri, Electrical Engineer

brian john said:
Electrician 480 where are you? Because I am not going into the office today to answer this one.
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I reside in New Orleans, you can e-mail me today. or call me on my cell . Thank you.

(Moderator’s Note: Edited to remove email address and phone number. If you wish to contact this person, then first send a Private Message via this Forum, and ask for the contact information.)
 
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Previous to 1940, there was a general limitation of 9 conductors in a conduit or tube. Exceptions were stage misc, signalling, motor / controllers, elevators, etc. Chapter 9, T3 1937.

Gotta go. More time later if needed.
 
Volta said:
Previous to 1940, there was a general limitation of 9 conductors in a conduit or tube. Exceptions were stage misc, signalling, motor / controllers, elevators, etc. Chapter 9, T3 1937.

Gotta go. More time later if needed.
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The 9 conductor rule is still enforced in Chicago.
 
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