 |
Wheatland TUBE COMPANY DIVISION OF JOHN MANEELY COMPANY |
Table 346-10 - Radius of Conduit Bends(Inches)
| Size of Conduit (In.) |
Conductors Without Lead
Sheath (In.) |
Conductors With Lead Sheath
(In.) |
| ½ ¾
1
1¼
1 ½
2
2½
3
3½
4
5
6 |
4 5
6
8
10
12
15
18
21
24
30
36 |
6 8
11
14
16
21
25
31
36
40
50
61 |
For SI units (Radius) One inch =
25.4 millimeters
Exception: For field bends for conductors
without lead sheath and made with a single operation (one shot) bending machine designed
for the purpose, the minimum radius shall not be less than indicated in Table 346-10
Exception.
Table 346-10 Exception - Radius of Conduit Bends
(Inches)
Size of Conduit (In.) |
Radius to Center of
Conduit (In.) |
| ½ ¾
1
1¼
1½
2
2½
3
3½
4
5
6 |
4 4½
5¾
7¼
8¼
9½
10½
13
15
16
24
30 |
For SI units: (Radius) one inch = 25.4
millimeters.
Bends-Number in One Run (346-11)
A run of conduit between outlet and outlet, fitting and fitting, or
outlet and fitting shall not contain more than the equivalent of four quarter bends (360
degrees, total) including those bends located immediately at the outlet or fitting.
Supports (346-12)-Rigid metal conduit shall be installed as a
complete system as provided in Article 300 and shall be securely fastened in place.
Conduit shall be firmly fastened within 3 feet of each outlet box, junction box, cabinet
or fitting. Conduit shall be supported at least every 10 feet. Exception No. 1: If
made up with threaded couplings, it shall be permissible to support straight runs of rigid
metal conduit in accordance with Table 346-12, provided such supports prevent transmission
of stresses to termination where conduit is deflected between supports. Exception No.
2: The distance between supports may be increased to 20 feet for exposed vertical
risers from machine tools and the like, provided the conduit is made up with threaded
couplings, is firmly supported at the top and bottom of the riser, and no other means of
intermediate support is readily available.
Table 346-12 - Supports for Rigid Metal Conduit
| Conduit Size (Inches) |
Maximum Distance Between Rigid Meal
Conduit Supports (Feet) |
| ½-¾ 1
1¼-1½
2-2½
3 and larger |
10 12
14
16
20 |
For SI units: (Supports) one inch=0.3048
millimeters
Boxes and Fittings (346-13)-Boxes and fittings shall comply
with the applicable provisions of Article 370.
Splices and taps (346-14)-Splices and taps shall be made only
in junction boxes outlet boxes or conduit bodies. See Article 370.
CONSTRUCTION SPECIFICATIONS General (346-15)-Rigid metal
conduit shall comply with (a) through (c) below.
(a) Standard Lengths. Rigid metal conduit as shipped shall be
in standard lengths of 10 feet (3.05m) including coupling, one coupling to be furnished
with each length. Each length shall be reamed and threaded on each end. For specific
applications or uses, it shall be permissible to ship lengths shorter or longer than 10
feet, (3.05m), with or without couplings and with or without threads.
(b) Corrosion-Resistant Material. Nonferrous conduit of
corrosion-resistant material shall have suitable markings.
(c) Durably Identified. Each length shall be clearly and
durably identified in every 10 feet (3.05m) as required in the first sentence of Section
110-21.
|
