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Underground Cable Ampacity Calculator
Calculate derating factors for cables installed in underground duct banks.
Base Ampacity (air)
?
Cable ampacity in free air.
A
Soil Temperature
?
Earth ambient temperature.
°C
Soil Thermal Resistivity
?
Soil thermal resistivity (90 typical).
°C·cm/W
Number of Circuits in Bank
?
Total circuits in the duct bank.
Burial Depth
?
Depth of duct bank.
inches
Calculate
Results
Temperature Derating
-
Grouping Derating
-
Derated Ampacity
-
A
References:
NEC Article 310; IEEE Std 835; Neher-McGrath Method