Form – 4
SECONDARY WIRE COMPUTATION
FOR T – 1
KVA SSPAN RIGHT SIDE
To determine the size of the wire of the secondary lines, assume V drop = 5% of
the operating voltage for no. of the span for 1ᴓ, 2 wire system.
From
P–1
to P – 2
I = Load KVA / 230
:Total load = 35.5270
=
Distance =
Total Load KVA:
Refer to table:
CM=
span, 11 volts, assume voltage drop at 5%
Total Maximum Demand of Transformer Bank
KVA Rating of Transformer
Refer to table:
Actual DC Voltage Drop, 50 °C, 60 Hz, 8ʺ spacing.
R= 1.89 Ω / mile
𝑿
𝑹
=
Xa= 0.145 Ω / mile
Xa + 9-0.049)
R
Actual DC Voltage Drop = (24 x d x I)/CM
Actual Voltage Drop factor at 0.85 p.f. =
Voltage Regulation =
ADV x df
𝑥
230
100
Use ________, Hard Drawn Copper Conductor
Xsf= 0.628 Ω / mile