superimpose
both
heating and cooling effects, i.e.,
– wind = cooling
– temperature, solar radiation = heating
June 2010 5
• Limit to how much heat the wire
can be
exposed to
•
Amount of
allowable current
based on
ambient conditions is known as ‘rating’
Network
capacity (
ampacity)
Too much heat
causes ‘sag’ where
minimum ground
clearance is not
achieved
June 2010 6
How are ratings determined
/media/ces/Cradden_Lucy_CES_2010.pdf