DC Volt Drop Calc

[YoungBart]

Hi all, I appreciate this has probably been posted to death but the search wont load on my phone.
I have to calculate for Volt drop in a DC circuit, There's next to no load (2 amps max) the cable is 4mm pvc twin, and ln a loop from the control unit to the loads. OveralL Length 50m Is the calc the same as for normal LV i.e. resistance of the cable x length x Ib /1000 or is it something completely different.
Thank in advance

James

 

[Lucien Nunes]

Yes. DC is the simplest possible case, it's just ohm's law applied, V(drop)=I(load) x R(cable). Single-phase AC calculations are done using the RMS value of current (i.e. when we speak of a 6A load it's understood to mean 6A RMS) because that makes the resulting heat dissipation / voltage drop etc. the same as for DC. On larger circuits the DC and AC figures deviate because the AC circuit must take inductance into account but the DC does not.