Steel Conduct

Cable  Capacities of Conduit

The following tables give guidence on the calculation of the number of single-core PVC insulated cables which can be located in various sizes of conduit.
The Table deal with two particular cases.
1. Single-core PVC insulated cables in straight runs not exceeding 3 meters in length.
2. Single-core PVC insulated cables in straight runs exceeding 3 meters in length or in runs of any length with bends or sets.

Straight Runs Not  Execeeding 3 Meters in Length

For each types of cable being used obtains the cable factor from Table 1. Sum all the cable factors and compare with the conduit factors given in Table 2.
The conduit sizes which will accommodate the cables are those with a conduit factor equal to or greater than the sum of the cable factors

Straight Runs Not  Execeeding 3 Meters in Length or Runs of Any Length Incorporating Bends or Sets

For each types of cable being used obtains the cable factors from Table 3. Sum all the cable factors and compare with the conduit factor given in Table 4 for the relevant length of run and the number of bends and sets in than run.

Spacing of Supports for conduits

The following table gives guidance on the spacing of supports for conduit.

These tables are based on the 16th edition of the I.E.E Wiring
Regulations Appendix 11.
These Tables are for guidance only and account needs to be
taken of future wiring needs