Product type: YJLY
Standard: GB/T 12706-2002
Characteristics and Application:
It applies to the transmission and distribution lines with rated voltage from 0.6/1 kilovolts to 26/35
kilovolts,while flame retardant power cable is used in the places with special demands of flame retardant
property,where cable is laid tightly.
Uo: rated power frequency voltage between conductor and shield or metallic sheath when cable is designed.
U: rated power frequency voltage between conductors when cable is designed
Um: max.equipment voltage (max.system voltage of the equipment in service)
Application of Products
maximum rated temperature of conductor is 90℃
maximum temperature is 250℃ when cable is shorted for less than 5 seconds
ambient temperature should be not lower than 0℃ when cable is installed
minimum bending radius is as follws when cable is installed
Calculation Condition of Ampacity
ambient temperature is 25℃(underground),40℃(air).
conductor working temperature is 90℃;
soil heat resistance coefficient is 1.0℃m/W. but not consider its rise resulted from water migration when it operates continuously.
gap between axis of cable and surface of ground is 700 millimeter when it is laid in earth
for many cable being laid in parallel, gap of axis of cables is 2 times O.D.