Permissible voltage drop 415V three phase power circuit

[atm84]

Can anyone tell me what the permissible voltage drop is for a three phase circuit serving a power circuit. Is it still 5% like for a 230V circuit. I don't have my BS 7671 to hand at the mo. Thanks in advance.

 

[telectrix]

BS7671 makes no distinction between single phase and 3 phase LV wrt volt drop, so your 5% is correct (3% for lighting)

 

[atm84]

Cheers

 

[D Skelton]

Tel is right in that the guidance given in the appendices is five and three percent, however it is only guidance. Other than appendix 1, all the other appendices are informative. What is the voltage tolerance of the three phase load? If it is for example 350V-460V then you can afford to drop 12.5% assuming a nominal of 400V, more if the supply voltage is higher.

 

[telectrix]

agreed^^^^.

 

[Knobhead]

What is this “power” circuit for?