Double check my VD calcs?

[1ManRiot]

Jusk seeking affirmation really, still new to this world and want to make sure I'm not making silly errors.

1). 6mm2 3-core SWA over 20m @ 230V: 6.6mV x 16A x 20m = 2.048V

2). 10mm2 3-core SWA over 20m @ 230V: 3.8mV x 20A x 20m = 1.52V

3). 16mm2 4-core SWA over 5m @ 400V: 2.4mV x 63A x 5m = 0.756V

4). 25mm2 3-core SWA over 5m @ 400V: 1.5mV x 80A x 5m = 0.6V

I'm using the 3% rule, so +/- 6.9V @ 230V and +/- 12V @ 400V, is that the correct percentage to use for both?

 

[telectrix]

3% is allowed for lighting. anything else, generally is 5%.

 

[1ManRiot]

(values taken from P339, Table 4D4B)

- - - Updated - - -

3% is allowed for lighting. anything else, generally is 5%.

Magic ta, will amend

 

[Richard Burns]

Just seeking affirmation really, still new to this world and want to make sure I'm not making silly errors.

1). 6mm2 3-core SWA over 20m @ 230V: 6.4mV x 16A x 20m = 2.048V: if 230V then only 2 live cores? so 7.3mV/A/m?

2). 10mm2 3-core SWA over 20m @ 230V: 3.8mV x 20A x 20m = 1.52V: if 230V then only 2 live cores? so 4.4mV/A/m?

3). 16mm2 4-core SWA over 5m @ 400V: 2.4mV x 63A x 5m = 0.756V OK

4). 25mm2 3-core SWA over 5m @ 400V: 1.5mV x 80A x 5m = 0.6V OK

I'm using the 3% rule, so +/- 6.9V @ 230V and +/- 12V @ 400V, is that the correct percentage to use for both?

Possible amendments above.
It looks like you are using maximum current rather than design current, design current would lower the values but they are well within so good to use worst case scenario.

 

[1ManRiot]

Possible amendments above.
It looks like you are using maximum current rather than design current, design current would lower the values but they are well within so good to use worst case scenario.

Good call, that's the silly mistake I was making!

Yeah intentionally worked with the fuse values basically for worst case scenario- this is more an amendment and addition rather than a new design.