Feeder Sizing

[ericstac]

What would you say to run to a 1000 amp main from a transformer that's 160ft away?

This would be copper wire and fed underground. thanks

 

[infinity]

3 sets of 600 kcmil would work.

 

[ericstac]

3 sets of 600 kcmil would work.

Sorry, I just updated it with using copper wire. Also if possible would need to feed it via 2 3" conduits. I've asked several other masters and they all said 3 sets of 500mcm copper would be good but the engineer doesnt agree.

 

[infinity]

If you're not worried about voltage drop 3 sets of 400kcmil copper gets you 1005 amps. Only two conduits complicates things.

 

[ericstac]

If you're not worried about voltage drop 3 sets of 400kcmil copper gets you 1005 amps. Only two conduits complicates things.

thanks, sounds like my calculations.. and 3 of 500kcml would be 1140 amps, right?

The EE is trying to say it needs to be 3-400kcml in THREE 3" conduits..

EDIT: just noticed you said the two conduits complicates things?

damn. 3 sets = 9 wires? yeah that would complicate things. I was thinking 3 pairs.

 

[ericstac]

so is there anyway to get it done with the 2 3" conduits?

 

[infinity]

so is there anyway to get it done with the 2 3" conduits?

What is the voltage and what type of conduit?

 

[packersparky]

so is there anyway to get it done with the 2 3" conduits?

What type of conduit? Three 900 kcmil will fit in a 3 inch EMT. The ampacity of two 900 kcmil thhn conductors is 1040 amps.

 

[infinity]

What type of conduit? Three 900 kcmil will fit in a 3 inch EMT. The ampacity of two 900 kcmil thhn conductors is 1040 amps.

I think that this is underground so EMT won't work.

 

[packersparky]

I think that this is underground so EMT won't work.

Oops. I missed that part.

 

[dionysius]

What would you say to run to a 1000 amp main from a transformer that's 160ft away?

This would be copper wire and fed underground. thanks

Single or three phase???? Cu or Al???

 

[petersonra]

Might be more cost effective to just move the Transformer.

 

[ericstac]

It is single phase and the transformer is pole mounted on the closest pole so there is no way of moving it. Sounds like the only way of doing this would be to add another conduit or change the main to 3ph huh..

 

[don_resqcapt19]

What is the neutral load? If the calculated neutral load is 532 amps or less, you could put five 400kcmil in each of the 2 conduits. Four for the ungrounded conductors and one for the neutral. That gives you an ampacity of 1064 amps for the ungrounded conductors and 532 for the neutral.

 

[ron]

Because it is underground, what configuration will the ducts be?

See Figure 310.60 for typical configurations and the associated tables or Figure B.310.15(B)(2)(2) and the associated tables depending on voltage.

If not a typical configuration, then get ready to do some calculations