  CableCalc F.A.Q.
 I am using CableCalc to calculate a fairly long
circuit but whatever I do the circuit 'fails'. It makes no difference
whatever size of circuit protective conductor (cpc) I add to the circuit
 Check that the source impedance for the installation
is correct. The quoted electricity supply authorities typical maximum
impedance values (0.35 ohms or 0.15 ohms for 300 Ampere supply) are unlikely
to be correct. If you can go to site and measure the Ze then your calculations
will be much more accurate.
How many cpc's can I include in a calculation when
sizing a cable?
If the cable has a sheath or armouring then that may be used
for the calculation together with options for using an internal core and/or
a separate earthwire (either automatically sized or selected).
What happens if the maximum size of cable is exceeded
when I am trying to calculate a cable size?
The load will be divided by two and two cables calculated
in parallel. If this still fails then the load will be divided by three
and three cables selected and so on up to a maximum of twenty cables.
I have designed a project with twelve distribution
boards feeding more than 300 circuits and now the architects have repositioned
the main transformer. This has completely changed all of the main incoming
figures, voltage, Ze, etc.
Simply input the revised source details and then click on
the 'Calculate all' button. The whole system will be recalculated using
the updated supply figures, and within a few minutes all of the circuits
in the project will have been recalculated.
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