Conduit Factors and Cable Calculation with Bends

This article helps you for single core or stranded PVC insulated cables longer than 3 meter the correct factor can be found. This is an easy way to find out how many cables can be passed through a conduit pipe made of metal or PVC. The following are examples of how many cables can pass through a conduit longer than 3 meters made of metal or PVC.

Three bend conduit exceeding 3 m size calculation 

E.g. Total stranded cables is 2.5 Sq mm wire 3 Nos, 1.5 Sq mm wire 4 Nos and 1.0 Sq mm wire 4 Nos.

Stranded cable factor 

2.5 Sq mm factor - 30, 1.5 Sq mm factor - 22 and 1.0 Sq mm factor - 16. Click here to know more stranded cable factors

2.5 Sq mm wire 3 Nos = 30 x 3 = 90

1.5 Sq mm wire 3 Nos = 22 x 4 = 88

1.0 Sq mm wire 4 Nos = 16 x 4 = 64

                  Total Cable Factor = 242 

So, You will need to select a conduit factor that is larger than the total cable factor. Find from the below table of 5 m 3 bend conduit factor. we select 2 size conduit for above calculated total cable factor.

1, Three bend 5 meter 20 mm Factor = 141

2, Three bend 5 meter 25 mm Factor = 260 

 

Therefore, single 25 mm conduit or double number 20 mm conduit can be used for the above mentioned total cable factor.

i.e. 20 mm factor 141 x 2 = 282, it is greater than total cable factor (242).

PVC or Metal Conduit Exceeding 3 m Factors

The chart below can be used to find the cable factor for pipes of combined conduit sets with one or more bends. This chart is used in electrical engineering to find the exact PVC or metal conduit for conductor cable of any length or for straight runs. Look at the figure below for the wire factor of straight, one bend, two bend, three bend and four bend.

Straight Conduit Factors Exceeding 3 Meter. In the previous article, we explained about the conduit factors going in a straight up to 3 m with its calculated examples. 

Straight Conduit Factors up to 10 meter

STRAIGHT CONDUIT PIPE FACTOR EXCEEDING 3 MTR

CONDUIT	16 mm	20 mm	25 mm	32 mm
LENGTH (MTR)
1	-	-	-	-
1.5	-	-	-	-
2.0	-	-	-	-
2.5	-	-	-	-
3.0	-	-	-	-
3.5	179	290	521	911
4.0	177	286	514	900
4.5	174	282	507	889
5.0	171	278	500	878
6.0	167	270	487	857
7.0	162	263	475	837
8.0	158	256	463	818
9.0	154	250	452	800
10	150	244	442	783

The chart above indicates a straight conduit factors greater than 3 m.

Conduit Factors with One Bend

ONE BEND CONDUIT FACTOR

CONDUIT	16 mm	20 mm	25 mm	32 mm
LENGTH (MTR)
1	188	303	543	947
1.5	182	294	528	923
2.0	177	286	514	900
2.5	171	278	500	878
3.0	167	270	487	857
3.5	162	263	475	837
4.0	158	256	463	818
4.5	154	250	452	800
5.0	150	244	442	783
6.0	143	233	422	750
7.0	136	222	404	720
8.0	130	213	388	692
9.0	125	204	373	667
10	120	196	385	643

The chart above mentions a curved conduit factors greater than 3 m.

Conduit Factors with Two Bends 

TWO BEND CONDUIT FACTOR

CONDUIT	16 mm	20 mm	25 mm	32 mm
LENGTH (MTR)
1	177	286	514	900
1.5	167	270	487	857
2.0	158	256	463	818
2.5	150	244	442	783
3.0	143	233	422	750
3.5	136	222	404	720
4.0	130	213	388	692
4.5	125	204	373	667
5.0	120	196	358	643
6.0	111	182	333	600
7.0	103	169	311	563
8.0	97	159	292	529
9.0	91	149	275	500
10	86	141	260	474

The chart above mentions the factors of conduit with two bend exceeding 3 m.

Conduit Factors with Three Bends 

THREE BEND CONDUIT FACTOR

CONDUIT	16 mm	20 mm	25 mm	32 mm
LENGTH (MTR)
1	158	256	463	818
1.5	143	233	422	750
2.0	130	213	388	692
2.5	120	196	358	643
3.0	111	182	333	600
3.5	103	169	311	563
4.0	97	159	292	529
4.5	91	149	275	500
5.0	86	141	260	474
6.0	-	-	-	-
7.0	-	-	-	-
8.0	-	-	-	-
9.0	-	-	-	-
10	-	-	-	-

The chart above mentions the factors of conduit with three bend greater than 3 m.

Conduit Factors with Four Bends 

FOUR BEND CONDUIT FACTOR

CONDUIT	16 mm	20 mm	25 mm	32 mm
LENGTH (MTR)
1	130	213	388	692
1.5	111	182	333	600
2.0	97	159	292	529
2.5	86	141	260	474
3.0	-	-	-	-
3.5	-	-	-	-
4.0	-	-	-	-
4.5	-	-	-	-
5.0	-	-	-	-
6.0	-	-	-	-
7.0	-	-	-	-
8.0	-	-	-	-
9.0	-	-	-	-
10	-	-	-	-

The chart above mentions the factors of conduit with four bend up to 2.5 m.

Conclusion

I hope you have learned from this article what is the Conduit factor and cable calculation with bend exceeding 3 m. Thanks for reading this article to understand the conduit and cable capacity factor in electrical wiring. Follow us our website eeetechs4u.com for newly updated articles on electrical engineering and technology.