Page 83 - MESINARUSTERUS
P. 83
Kuasa masukkan, Pin = Vt IfL
Oleh itu, Ifl = = = 68.26 A
Energy absorbed in 10 hours = 30.72kW x 10 = 307.2kWh
Cost of the energy absorbed = RM307.2 x RM 0.30 = RM92.16
Contoh 3.16
Sebuah motor pirau at 480V, mempunyai rintangan angker sebanyak 0.5Ω,
rintangan medan sebanyak 150Ω. Dapatkan nilai voltan balikan (back emf) bila
kuasa motor ini sebanyak 10 kuasa kuda (horse power) pada kecekapan 80%.
Penyelesaia 3.16
%kecekapan = x 100%
= = = 9325W
Kuasa masukkan, Pin = Vt IfL
Arus masuk motor, Ifl = = = 19.43 A
Ish = = = 3.2A
Ia = Ifl - Ish = 19.43A – 3.2A = 16.23A
Voltan balikan
Eb = Vt – Va – Vburses
= 480V – (16.23 x 0.5) = 471.9V
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