Conduit Cable Calculations

[bushynut]

Ok, I'm revising cable calcs etc, and I would like to know if any1 can point me in the rite direction for information conserning circuits that are housed in conduit and the factors that have to be applied in the conduit sizing calcs.

So basically how do you calculate conduit size, in relation to a circuit design

Thanks in advance

 

[Jim2287]

onsite guide has tables for it

 

[Lectrician]

Once you have determined the cable sizes and number of cables that will be pulled into the conduit, after applying the standard factors (grouping, thermal insulation, ambient temp, 3036 fuse), and checking volt drop, EFL and thermal constraints (as you would for any standard ciruit calc). You then need to determine the the conduit size.

Look in the OSG, and use the charts to add together the cable factors.

In one chart, conduit will be given a cable factor depending on number bends/length of run.

In another chart, cables will have a figure depending on size etc.

Add the cable figures together for each cable to be pulled in, and select a conduit size that has a higher factor than the calc.

Sorry, no regs to hand to give an example, or to use correct terminoligy!