Full Load Current

2.1       Perhitungan Full Load Current (I_FL)

2.1.1    Mengacu pada data vendor atau Handbook

2.1.2    Rumus :

• 3 phase circuit sistem AC :

I _FL  =  (kW x 1000)/(√3 x V _SYS x cos φ x E _FF)

 Dimana :

kW             Equipment Load

V_SYS              System Voltage (V)

I_FL              Full load current (A)

φ                Sudut pergeseran arus dan tegangan (degree)

E_ff                    Power Efficiency

• Single phase circuit sistem AC :

I _FL  =  ( kW x 1000)/(V _SYS x cos φ x E _FF)

• Sistem DC :

I _FL  = (kW x 1000)/(V _SYS)

2.2              Perhitungan Susut Tegangan

2.2.1    3 phase circuit sistem AC :

% V_DROP =   (√3 x l x I_FL x (R cos φ + X sin φ) x 100)/(V_SYS x n x 1000)

Dimana :

V_SYS                      System voltage (V)

% V _DROP               volt drop (%)

l                             Length (m)

I_FL                          Full load current (A)

R                           Cable resistance (Ω/km)

X                           Cable reactance (Ω/km)

φ                            Sudut pergeseran fasa (degree)

n                            Number of cables in parallel per phase

2.2.2        Single phase circuit sistem AC :

% V_DROP =  (2 x l x I_FL x (R cos φ + X sin φ) x 100)/(V_SYS x n x 1000)

 2.2.3        sistem DC :

% V_DROP =  (2 x l x I_FL x R x 100)/(V_SYS x n x 1000)

2.3              Resistance Konduktor

2.3.1    Resistance Formula

R = ρ x (l /A)

Dimana :

R   Resistance (Ω/phase)

ρ    Tahanan Jenis (Ω.mm²/m)

l     Panjang Konduktor (m)

A   Luas Konduktor (mm²)

2.3.2        Resistance Fungsi dari temperature

R = R_o [ l + α (t-20)]

Dimana :

R_o   Resistance at t = 20^oC

t     Conductor temperature (^oC)

α    0.00393 for Copper

2.4              Reactance

X = 2 x f x π x L x l

Dimana :

X   Reactance (Ω/phase)

f     Frequence (Hz)

L    Inductance (H/m)

l     Conductor length (m)ф