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.

STEEL CONDUIT
Material    :    Steel
Finish    :    Hot Dip Galvanised / Pre Galvanised
Standard    :    Class 4: As per BSEN 61386 BS EN         50086-2-1: 1996 BS 4568 Part 1: 1970
Supplied in a standard length of 3.75 meters with threaded both ends where one end fitted with coupling and the other protected by plastic end cap
Note: Pre Galvanised conduits does not meet the
requirements of BS 4568.

Conduit