#4 ser in a conduit

O

olly

Senior Member
Location
Berthoud, Colorado
Occupation
Master Electrician
I have to pipe across a garage and then enter an attic, will #4 SER cable fit in a 1" conduit by code? I believe #4 SER is 3-#4's with a bare #4 so 4 #4's total plus insulation I hate to have to set a j box, splice than switch to SER if I were to use THHN in the conduit. The conduit will have 2 90's plus a kick. Thank you in advance
 
You have to use the diameter of the SER to find the equivalent single conductor size. You cannot just use 3-#4's and the table fill value for 1". The fill for a single conductor is 53%. So if your SER is equivalent to say a 750 kcmil single conductor then you use the 750 value when searching the table. For example if your SER diameter equals 1-750 kcmil and you were using EMT the 1-750 kcmil conductor would require a 1½" raceway from Table C1. Otherwise you'll need to do the long hand calculation with 53% fill.
 
olly said:
I have to pipe across a garage and then enter an attic, will #4 SER cable fit in a 1" conduit by code? I believe #4 SER is 3-#4's with a bare #4 so 4 #4's total plus insulation I hate to have to set a j box, splice than switch to SER if I were to use THHN in the conduit. The conduit will have 2 90's plus a kick. Thank you in advance
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Remember you have to treat a cable as a single conductor with 53% fill. Also pretty sure #4 SER has a #6 EGC. Based on a quick and dirty calc its super close, depending on who spec you use for cable OD. You could strip it and with individual conductors you will be well within fill.

(didnt notice Rob had posted, what he said....)
 
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