james_mcquade
Senior Member
Hi everyone,
I designed a control system for a company in which i stated (2) conduits to an operator control panel.
The system is 24 volts dc and all conductors are less than 1 amp.
#1 had (90) #14 THHN conductors including spares and a 2" rigid conduit.
#2 had (4) instrumentation cables of approx. 1/4" diameter and a 1 1/4" rigid conduit.
the budget was tight so i did my best to keep the system cheap, but i had to design it correctly.
i went back today as the final debug of the system was being done and found that
conduit #1 was run with (87) #14 thhn wires run in a 1 1/4" rigid conduit not the 2" i specified.
conduit #2 was also 1 1/4" as specified.
Ok, i admit that many contractors would probably pull 90 wires in a 1 1/2" conduit and be ok with it,
but 87 wires in a 1 1/4" conduit.
when i asked the electrical contractor how he got around the conduit fill rule, he said that because
the system was 24 volts and less than 1 amp, he could use 80% of the fill for the conduit.
He did not cite book, chapter & verse but would be happy to for a fee.
My question is, have i missed something that would allow him to use 80% of the fill capacity?
If so, please tell me the code.
Thanks in advance,
James
I designed a control system for a company in which i stated (2) conduits to an operator control panel.
The system is 24 volts dc and all conductors are less than 1 amp.
#1 had (90) #14 THHN conductors including spares and a 2" rigid conduit.
#2 had (4) instrumentation cables of approx. 1/4" diameter and a 1 1/4" rigid conduit.
the budget was tight so i did my best to keep the system cheap, but i had to design it correctly.
i went back today as the final debug of the system was being done and found that
conduit #1 was run with (87) #14 thhn wires run in a 1 1/4" rigid conduit not the 2" i specified.
conduit #2 was also 1 1/4" as specified.
Ok, i admit that many contractors would probably pull 90 wires in a 1 1/2" conduit and be ok with it,
but 87 wires in a 1 1/4" conduit.
when i asked the electrical contractor how he got around the conduit fill rule, he said that because
the system was 24 volts and less than 1 amp, he could use 80% of the fill for the conduit.
He did not cite book, chapter & verse but would be happy to for a fee.
My question is, have i missed something that would allow him to use 80% of the fill capacity?
If so, please tell me the code.
Thanks in advance,
James