QES
Senior Member
- Location
- California
Anyone know the Art. where nec mention about limits on diff. conductor sizes in same conduit.
QES said:Anyone know the Art. where nec mention about limits on diff. conductor sizes in same conduit.
QES said:Anyone know the Art. where nec mention about limits on diff. conductor sizes in same conduit.
charlie b said:There is no such requirement. You can put a 500 MCM and a #18 in the same conduit if you wish. I wouldn't recommend it, but I know of is no rule against it.
K8MHZ said:A few years back in a school job I was on the state inspector let us put 108 #8s in a 200 foot long run of 3" EMT because we were de-rating them to 20 amps apiece.
K8MHZ said:A few years back in a school job I was on the state inspector let us put 108 #8s in a 200 foot long run of 3" EMT because we were de-rating them to 20 amps apiece.
Ever see back to back tuggers break a good size chain? The scale only went to 2900 lbs and it was maxed out when the chain broke. We got a bigger chain and the head broke off the pull. Luckily for us it was inside the last nipple which was 12 inches long and we were able to pop it off and save the pull.
That was an interesting week....
Often when you are pulling large and small conductors in the same raceway, the smaller conductors will break if you have bends in the pull. I would never even think about trying to pull #18 in with 500kcmil.kpepin said:I've seen it done a million times. You have a large motor that has an internal thermal switch which is intended to be wired into the control circuit. Are you going to run seperate conduits into the ph of the motor (Which normally only has one knockout and is shaped in such a way to make adding another KO difficult) or just pull it all in one? As long as the conduit fill is correct and any derating issues are addressed, you are good
K8MHZ said:A few years back in a school job I was on the state inspector let us put 108 #8s in a 200 foot long run of 3" EMT because we were de-rating them to 20 amps apiece.
Ever see back to back tuggers break a good size chain? The scale only went to 2900 lbs and it was maxed out when the chain broke. We got a bigger chain and the head broke off the pull. Luckily for us it was inside the last nipple which was 12 inches long and we were able to pop it off and save the pull.
hardworkingstiff said:The conductors were all OK?
kpepin said:3" EMT only 96 #8 THHN allowed
41+ #8 only good for 19.25 Amps based on 90 degree chart
I hope this was a typo
peter d said:I'm sure there are many more details you can add to that story, but that sounds pretty horrific!
K8MHZ said:Please note that I counted the grounding conductors with my figure. 36 circuits with three wires each.
That is exactly what I had in mind, when I said that I wouldn't recommend doing this.don_resqcapt19 said:Often when you are pulling large and small conductors in the same raceway, the smaller conductors will break if you have bends in the pull.
peter d said:A separate ground wire for every circuit????? Job spec?