Quick Volt drop Q re Table 4ab P 383 Regs Book plz

[John-]

Hi

I am being thick i am sure. I am doing some pre work on an EV charging course i am doing in November. I got to a part mentioning volt drop and ref in the regs book. Not looked at this for a while, so i thought i better check it out. Table states figures for Public Supply and figures Private supply. What do they mean by Private and public please and why should there be a difference? Also i see that in the note section the longer the run, the more lenient it gets by adding on an additional .005% up to a max of .5% - i think. Why is that?

IBTWi get the part about being suitable for the equipment supplied, Motors, sanative kit and that this is not a reg just informative i think.



Thanks

Johnm

 

[Rockingit]

The clue is to be found at the bottom of page 381

 

[buzzlightyear]

What do they mean by Private and public

high ways , transformers ect .

 

[John-]

high ways , transformers ect .

Thanks. But why should private be more lenient? Is it because they are less likely to misapply, better design authority?

 

[buzzlightyear]

Thanks. But why should private be more lenient? Is it because they are less likely to misapply, better design authority?

because its much better straight off the grid in some cases .

 

[John-]

The clue is to be found at the bottom of page 381

Thanks. Pessimism due to ambient temp you mean? Still does not add up, surely op temp factor would be better to apply? Or am i missing the point?

 

[buzzlightyear]

Thanks. Pessimism due to ambient temp you mean? Still does not add up, surely op temp factor would be better to apply? Or am i missing the point

missing the point , if you read beyond page 381 it will give you the answer .

 

[Rockingit]

My understanding is that a 'private' supply is effectively anything downstream of an isolation transformer or generating plant (ie, say you had an AC motor used to rotate a dynamo for DC output). Happy to be educated though.