VOLTAGE DROP - HIGH-RISE BUILDINGS

Erika Duran

Sustainability Consultant

Dagher Engineering

LEEDuser Basic Member

51 thumbs up

August 15, 2011

The ASHRAE requirement (Prerequisite for LEED) limits voltage drop in feeders to 2% based on demand. So while the ampacity of the cables is well below the allowable maximum, voltage drop becomes the limiting factor in high-rise buildings. The NEC limits the feeders to 3% voltage drop (5% overall). Can anyone comment on the counter-productive nature of this requirement for cities like New York? The larger feeder sizes in high-rise buildings becomes costly for owners and takes up more space. How is this an energy saving measure?

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Ante Vulin

Sustainability Manager

YR&G

LEEDuser Basic Member

55 thumbs up

Thu, 07/19/2012 - 13:17

Amanda, apologies that this is so late but for anyone else searching "feeders," please note recent interpretation #10218 dated 7/1/2012 which states that "the mandatory provision of ASHRAE 90.1-2007/2010 Section 8.4 will be met as long as the total voltage drop does not exceed 5%." The total voltage drop is defined over "from service entrance to the worst-case connection"

Giorgia Lorenzi

Engineer LEED AP

Strategie d'Impresa

LEEDuser Basic Member

0 thumbs up

Thu, 07/19/2012 - 13:57

Ante where can I find this interpretation? I looked for in the interpretation section of ASHRAE website but I've not found it. Thank you. Giorgia

Ante Vulin

Sustainability Manager

YR&G

LEEDuser Basic Member

55 thumbs up

Thu, 07/19/2012 - 15:43

Giorgia, this a LEED interpretation, which you can find by going to https://www.usgbc.org/leedinterpretations/lilanding.aspx and searching for "10218"