Voltage drop problem

[RCDGuy]

I think I am making a mistake:
I have a lighting circuit (see attached) where the voltage drop is showing as unacceptable.
From appendix 4 for type B cable installation in conduit. for 1.5mm T+E for lighting my calculation is

Voltage Drop = (mV/A/m) x Ib x L / 1000
(mV/A/m) from table = 29
Ib for the circuit shows as = 1.6
L of the circuit is 15m
so VD should b 0.696 - according to my calculation

However, the VD in the app is shown as = 4.37 %

Max VD for lighting circuit is of course 3%

What have I done wrong?

[Mert]

Hello,

The total VD is affected by the upstream cable. Make sure you have the upstream cable correctly sized.