|
Variable |
Description |
Units |
|
Rcap |
Overall thermal resistance between conductor & ambient |
Thermal ohm-ft |
|
Rd |
Duct thermal resistance |
Thermal ohm-ft |
|
Rdc |
Conductor dc resistance at conductor specified or rated
temperature |
microhms/foot |
|
Reactance |
Conductor ac reactance used for voltage drop calcs |
ohms/1000 feet |
|
Resistance |
Conductor ac resistance used for voltage drop calcs |
ohms/1000 feet |
|
Ri |
Insulation thermal resistance |
Thermal ohm-ft |
|
Rj |
Cable Jacket thermal resistance |
Thermal ohm-ft |
|
Rsd |
Thermal resistance between cable exterior and duct interior |
Thermal ohm-ft |
|
Shield |
Cable shielded? Yes or No |
|
|
Shield |
Shield grounding, No shield, Shield w/1 end grd or Shield
w/2 end grd |
|
|
Shield Dia |
Shield mean diameter |
Inches |
|
Shield Rdc |
Shield dc resistance |
microhms/foot |
|
Shield Th |
Shield thickness |
Inches |
|
Shld X |
Mutual reactance conductor to shield |
Microhms/foot |
|
SIC |
Insulation Specific Inductive capacitance (SIC), SIC = SIC x
e^(SIC exp x Temp) |
|
|
SIC Exp |
Insulation SIC exponent, overall SIC = SIC x e^(SIC exp
Temp) |
|
|
Size |
Cable size designation |
|
|
Spacing |
Spacing between conductors in the same phase group |
Inches |
|
Specified Amps |
Specified conductor current |
Amperes |
|
Specified Temp |
Specified conductor temperature |
Deg C |
|
Sys Freq |
Applied power frequency in cable |
Hertz |
|
Sys kV |
Applied cable line-to-line kilovolts |
kilovolts |
|
System |
Number of system (assigned in order entered) |
|
|
Temp |
Calculated or specified total conductor temperature |
Deg C |
|
Thermal Factor |
Factor specifying relative heating at each cable position |
|
|
Type of underground system |
Type of underground system, ductbank or direct buried |
|
|
Underground system filename |
Path and *.ugs filename where underground system data stored |
|
|
Voltage Mag |
Source or load voltage magnitude in load flow calcs |
Volts |
|
Voltage Deg |
Source or load voltage phase angle in load flow calcs |
Degrees |
|
Volt Drop (+%) or Rise (-%) |
Voltage drop or rise across circuit length, = 100 x (Vsource-Vload)
/ Vsource |
% |
|
Watts/ft |
Total cable watts loss per foot |
Watts/foot |
|
Wd |
Cable dielectric loss |
Watts/foot |
|
x Coord |
Position x coordinate |
Inches |
|
y Coord |
Position y coordinate |
Inches |
|
Yc |
Increment of Rac/Rdc ratio due to conductor effects =
Ycs + Ycp |
|
|
Ycp |
Increment of Rac/Rdc ratio due to conductor proximity effect |
|
|
Ycs |
Increment of Rac/Rdc ratio due to conductor skin effect |
|
|
Yp |
Increment of Rac/Rdc ratio due to pipe or conduit losses |
|
|
Ys |
Increment of Rac/Rdc ratio due to total shield losses = Ysc
+ Yse |
|
|
Ysc |
Increment of Rac/Rdc ratio due to circulating currents in
shield |
|
|
Yse |
Increment of Rac/Rdc ratio due to eddy currents in the
shield |
|