Volt drop calculations

[IAmSparkytus!]

Just curious as to when people are calculating volt drop, how close you allow your calculations to get to the 3% and 5% values before you decide to up the cable size?

For example, if your calculations brought you to 11V for a general circuit would you be OK with that?

 

[UNG]

A lot depends on what I'm calculating the volt drop on, if you have sub mains and final circuits involved it gets a bit more complicated balancing the volt drop across the two

 

[Rockingit]

Try worrying about 800A feeds across 400m.......

 

[Rockingit]

Just curious as to when people are calculating volt drop, how close you allow your calculations to get to the 3% and 5% values before you decide to up the cable size?

For example, if your calculations brought you to 11V for a general circuit would you be OK with that?

Serious answer - depends on what it is. If it's a socket in someone's outhouse for a dewault charger then have at it. If it's a critical designed medical device, probably not.

 

[pc1966]

To be honest I would worry less about 3% for lights as these days most are LED and far less sensitive to voltage variations.