Question

The three figures below show a balanced three phase Delta, its Wye equivalent and the single phase equivalent of the three phase Wye. All three representations have a complex load ZALD or ZYLD and a complex line impedance ZLINE Refer to these diagrams when answering questions 1-4. ZLINE Vab= 679 L 30° ZLINE ZALD ZLINE = 2+1 DELTA ZALD= 18+24j2 LINE ZLINE ZLINE ZYLD 7yun WYE WYE ZYLD ZLINE ZLINE Van Complex Load ZYLD Single Line WYE

Answer 1

Van 1) Letter from formula banki w Vas Vos caso - - 679 230 = 39220° 130 ophon CA 2) Letter from formula banki v Zy=ZA/3= 8+243 = 6+8 =ZYLD option (A) 3) Letter from formula bank's no t a Ztotal = Zuni & Zyly . = /1487345+ 16+78 3 = 2+1J + 6+8j > 8+ 9j option (2)

D 4) Letter from formula bank i I dreta G Cument ca single line dove - Tài = Van 1. Zu Lo + Zuni La Gomendo 392 Lo t hair QUELT 6+8°) +(2+19) Eyes = 32.55 L - 48:36 A All option are incorrect-(All loads are inductine) 5) Letter from formula bank? H Power angle o= tanl/Imaginary (2) Real (2) - tant ( 24 ) = 53130 option (c) T WITTER (6) letter from formula bank : M. se vorms Ins t ant Voms? 480 V Saj O = 30 Imms = 15ASTO ca 7200VA = 7.2KVA ~ 7 kVA option (A)

7) Letter from formula banki k Real power pa Vome Irms cos o w = 480X15x cos 30 = 6235 W = 6.2 kW ✓ 6kw option (B) 8) Letter from formula bank it Reactine power 8= Vorms Inns sui o VAR = 4800158563D = 3600VAR = 3.6kVA ? YKVA option (B)