One line diagrams representation

[lume7006]

Dear colleagues,

This may be a very fool question, however, I would like to receive some feedeback related to the standarized way to express in a single line diagram the following:
Size of conductors
Number of conductors

Typically, we receive many one line diagramas showing data in a non standarized format, let's say:
12-500 kCM
When we ask to the person who did it, the answer is 4 conductors per phase, however, sometimes, we have seen that the feeder ampacity only "matches" with 12 conductors per phase.

I guess there should be a standar way to express this and avoid confusions, because of that I hope that from your experience may recommended me something to look for and avoid mistakes.

Best Regards,

 

[dpc]

There are customs, but no standards, at least in the US.

To reduce ambiguity and opportunity for contractor creativity, we generally would write:

4-500 kcmil/phase

or

4-4"C with [3-500 kcmil, 1-#4/0G] each

This is also covered in our legend.

In your part of the universe, the custom may be totally different.

 

[lume7006]

Hi dpc,

I thank your reply!

As you mentioned, sometimes, our customer has enough creativity, some other, even the customer does not have a clear idea of the meaning because has had so many contractors and each one defined its own style but there´s nothing written.

We typically follow our national code which is almost a translation of NEC, however, as you stated, there is no code!

Best Regards

 

[dpc]

The contractor's creativity generally runs toward finding new reasons why a change order is required.

Probably putting an example in the legend is the best approach.

 

[WoodrowJWeen]

I would normally write ... 4 sets each: 3#500, 1#4/0G - 4". Pretty obvious to me and never been questioned. And no I don't write MCM or kcmil for that matter. Still think kcmil sounds like the name of a country singer.

 

[jghrist]

I would normally write ... 4 sets each: 3#500, 1#4/0G - 4". Pretty obvious to me and never been questioned. And no I don't write MCM or kcmil for that matter. Still think kcmil sounds like the name of a country singer.

But #500 is meaningless.