HT Cable Sizing

Electrical Basic Calculators

 HT Cable Size 

Cable sizing play import role while installing a Electrical load, Because Voltage drop and heating play important role to decide life of load and cable. The HT cable is based on short circuit current so below method calculate the size of cable based on HT fault current and voltage drop. Below Yellow Highlighted Data can be change by user and Green is output.

HT CABLE SIZING
1	HT cable size by short ckt calcuation	S = (I SC *√t ) / K		S= Nominal cross sectional area of the conductor in mm2
				I SC = Value of fault current or short circuit current in KA
				T=Fault clearing time in seconds (1 second or 3 second)
				K= Factor taking account of the resistivity, temperature co-efficient, heat capacity of the conductor material, initial and final temperature. Value of K (as per BS 7671) shall be taken as 0.094 for XLPE insulated Aluminium cables, 0.143 for XLPE insulated Copper cables and 0.076 for PVC Insulated Aluminium cables
								I = (K*A)/ √ t
		ISC		KA
		T		second				insulation)
		K		(K=0.094 for aluminum conductor with XLPE insulation) & (K= 0.144 for copper conductor XLPE Insulation)
		S		in mm2
		Selected HT CABLE Minimum Size		in mm2
2	HT Cable Current Calcualiton	I= (KVAX1000)/ (KVx1000)
		KVA of load		KVA
		KV of voltage		KV
		I		A
3	Voltage Drop calculation	Fault cuurnet		kA
		Voltage		kV
		Cable Length		meter
		Power Facor
		Resistance		(ohm/km) asper selected cable
		Reactance		(ohm/km) asper selected cable
		Rounded cable run
		ᶲ
		sin ᵩ
		Voltage Drop =		%