Note: This will be the first of a series of tutorials for the selection of cables.
The objective of this tutorial is to enable the Electrical Engineer, a designer or an electrician to properly select or check cable sizes. This tutorial uses the power of the excel worksheet to perform calculation and determine the length of cables given the size of the circuit breaker or fuse. The values in this example are based on AS 3008.1.1- 1998. Current-carrying capacity is based on a two-core 75°C PVC cable installed in air touching. All parameters such as power factors, derating factors, ampacities, etc are replaceable to suit any application.
How to use the table. It is best to provide an example to illustrate how easy it is to select a cable given some parameters.
Example 1.
Circuit Breaker Rating : 16 A
Cable Length : 230 m
Determine the size of a suitable cable.
How to:
Under the MCB / Fuse Column, move down to 16.00, then to the right, select 306 (which is longer than 230m) then move up to the CSA row. The cable size
The shaded portion of the table means that the cable is not allowed to be used as the cable protection device (MCB/Fuse) has a higher rating than the current carrying capacity of the cable.
The advantage of this type cable selection is that even non-engineers, ie drafters/designers, are able to create, say a cable schedule, even without much assistance from an Engineer.
Please read disclaimer before downloading and using this material.
Download link: Cable Selection - Single Phase