ConduitCount

How many #1/0 THHN fit in 1-1/4" Rigid?

31/0 AWG THHN/THWN-2 wires in 1-1/4" Rigid metal conduit (RMC, GRC)

1.526 sq in × 40 % = 0.6104 sq in allowed. ÷ 0.1855 sq in per wire = 3.29, so 3.

3 #1/0 THHN in 1-1/4" Rigid, drawn to scale

This pull in numbers

3 wires fill
36.5 % of 1-1/4" Rigid
Limit for three or more
40 %
For 4 or more
1-1/2" Rigid, up to 4
Pipe to wire diameter
2.87 to 1
In THW insulation
2 fit
In XHHW-2 insulation
3 fit

The pipe is 2.87 times the wire's diameter, inside the 2.8 to 3.2 range where three wires can wedge side by side on a pull. If you pull exactly three, go up a size or pull with care.

Before you pull 3

#1/0 THHN in other 1-1/4" conduit

#1/0 THHN in other Rigid sizes

Other wire sizes in 1-1/4" Rigid

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