[RE-wrenches] 3-phase wire run considerations

[Luke Christy]

Hi Folks,
In several months we will be installing a 100kW ground mounted PV  
system for one of our commercial customers. I'm in the planning stage  
and am looking at the wire runs. The site requires a 700' underground  
wire run between the 480V service and the single central inverter  
located at the array (a PVP100kW unit). I have two related questions:
1: Given the significant cost of the AC cabling for this situation,  
what is the most appropriate number to use for current in running  
voltage drop calcs? The wiring is going to be significantly oversized  
to achieve a ~1% VD at this length. I could use the max rated output  
current of the inverter (120A), but that seems like it might be overly  
conservative. Opinions?

2: It looks like the most cost effective and manageable solution for  
this run will involve several paralleled sets of cables. How important  
are the considerations of careful cable bundling? ie: putting several  
conductors per phase willy nilly in a trench vs having separate  
triplexed bundles.

Thanks in advance for your thoughts.



Luke Christy

NABCEP Certified PV Installer™: Certification #031409-25 (Luke Christy)
NABCEP Certified Solar Thermal Installer™: Certification #ST032611-03
  CoSEIA Certified PV Installer (Luke Christy)

Solar Gain Services, LLC
Monte Vista, CO.
SGSRenewables at Gmail.com






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