IPS vs EHIPS aluminum tubular bus

[veegrid]

I know IPS aluminum bus and current rating with Sch.40 and Sch.80 bus as per IEEE-605.
However, recently I cam across acronym "EHIPS" and it was giving about 10% ampacity than IPS tubular bus.

I am not sure what EHIPS stand for and what other specification I should tell fabricator when ordering EHIPS.

 

[dauwerda]

IPS is Iron Pipe Size (schedule 40). EHIPS is Extra Heavy Iron Pipe Size (schedule 80)