Volt drop..................................................

[drzsta]

hi all,

I have a situation where I would need to supply a 40kW installation from a Generator situated 300 meters away (not ideal). As this is a private LV supply up to 8% VD is permissible as per App. 4 Sect 6.4 in the BYB. However it then goes on to state that final circuits should not exceed public LV supply values of 5%.

The way I am interpreting this is that I can have up to 8% on my distribution cable to the origin of the installation(the DB) then a further 5% for final circuits.

This would lead to a possible situation of 348V L-L at the furthermost point in the installation if it did not contain lighting ccts.

Is this how others interpret it with respect to Section 525?

cheers,

 

[Richard Burns]

I think that you are being optimistic with that interpretation.
I think the meaning is that the total volt drop from origin to load cannot exceed 8% (6% for lighting) of that 8% only 5% can be dropped over the final circuit the remaining 3% can be dropped only over the distribution circuit.

 

[drzsta]

Thanks Rich, that'll teach me for trying to work on a Friday night!