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Sizing Of Diesel Generator

Sizing Of Diesel Generator


Size a diesel generator for following electrical load. Future  load expansion is 20%. Average use of equipment is 0.8.

1) 5 No. of 1 Ph, 230 V, 100 W, CFL bulb, diversity factor is 0.8, starting and running pf is 0.9.
2) 3 No. of 1 Ph, 230 V, 2500 W, Air conditioner with diversity factor of 1, starting and running PF is       0.9.
3) 4 No. of 1 Ph, 230 V, 600 W, halogen lights. Diversity factor is 0.8, starting and running PF is 0.9
4) 2 No. of 3 Ph, 430 V, 15 KW motor with Y-D starter having diversity factor of 0.8, starting P.F is        0.8 and running P.F is 0.9.
5) 2 No. of 3 Ph, 430 V, 100 KW, motor with soft starter having diversity factor of 0.8, starting P.F is      0.8 and running P.F is 0.9


Starting Current of linear and non-linear loads
Type Of Load
Equipment
Starting Current
Linear Load
General
100% of full load current
Non-linear load
UPS, Inverter, Computer, Ballast
160% of full load current



Starting Current of different starters
Type Of Starter
Starting Current
DOL
6×Full load Current
Star-Delta
4×Full load Current
Auto Transformer
3×Full load Current
Soft starter
2×Full load Current
VFD
1.5×Full load Current






Load Calculation 1:
F.L KW of CFL bulb = (No*Watt*D.F)/1000
                                   =(5*100*0.8)/1000
                                   =0.4 KW
F.L KVA of CFL bulb= KW/P.F
                                   =0.4/0.9
                                   =0.45 KVA
F.L KVA of CFL bulb= (No*Watt*D.F)/(Volt*P.F)
                                   =(5*100*0.8)/(230*0.9)
                                   =1.93 A
Type of load              = Linear
Starting KVA of CFL bulb = 1 *(KW/starting P.F)
                                            = 1*(0.4/0.9)
                                            =0.45 KVA
Starting current of CFL bulb  = 100% of F.L current
                                                =1*1.93
                                                = 1.93 A

Load Calculation 2:
F.L KW of A.C         = (No*Watt*D.F)/1000
                                  =(3*2500*1)/1000
                                  =7.5 KW
F.L KVA of A.C       = KW/P.F
                                  =7.5/0.9
                                  =8.33 KVA
F.L Current of A.C    = (No*Watt*D.F)/(Volt*P.F)
                                  = (3*2500*1)/(230*0.9)
                                  =36.23 A
Type of load              =  Non-linear 
Starting KVA of A.C  = 1.6*(KW/starting P.F)
                                    =1.6*(7.5/0.9)
                                    =13.33 KVA
Starting current of A.C  = 160% of F.L current
                                       =1.6* 36.23
                                        = 57.97 A
Load Calculation 3:
F.L KW of halogen bulb =  (No*Watt*D.F)/1000
                                        =  (4*600*0.8)/1000
                                        = 1.92 KW
F.L KVA of halogen bulb = KW/P.F
                                         = 1.92/0.9
                                         = 2.13 KVA
F.L current of halogen bulb =  (No*Watt*D.F)/ (Volt*P.F)
                                             =  (4*600*0.8)/(230*0.9)
                                             =  9.27 A
Type of load                         =  Non-linear
Starting KVA of halogen bulb = 1.6*(KW/Starting P.F)
                                                 = 1.6*(1.92/0.9)
                                                 =3.41 KVA
Starting current of halogen bulb = 160% of F.L current
                                                    = 1.6*9.27
                                                    = 14.83 A
Load Calculation 4:
F.L KW of motor             =  (No*Watt*D.F)/1000
                                        =  (2*15000*0.8)/1000
                                        =  24 KW
F.L KVA of motor          = KW/P.F
                                       =24/0.9
                                       = 26.67 KVA
F.L current motor          =     (No*Watt*D.F)/ (Volt*P.F)
                                      =  (2*15000*0.8)/(1.73*430*0.9)
                                      =  35.8 A
Type of starter              = Star-Delta
Starting KVA of motor = 4*(KW/Starting P.F)
                                     = 4*(24/0.8)
                                     = 120
Starting current of motor = 4* F.L current
                                         = 4*35.8
                                         = 143.2 A

Load Calculation 5:
F.L KW of motor             =  (No*Watt*D.F)/1000
                                        =  (2*100000*0.8)/1000
                                        =  160 KW
F.L KVA of motor          = KW/P.F
                                       =160/0.9
                                       = 177.78 KVA
F.L current of motor      =     (No*Watt*D.F)/ (Volt*P.F)
                                      =  (2*100000*0.8)/(1.73*430*0.9)
                                      =  238.98 A
Type of starter              = Soft starter
Starting KVA of motor = 2*(KW/Starting P.F)
                                     = 2*(160/0.8)
                                     = 400 KVA
Starting current of motor = 2* F.L current
                                         = 2*238.98
                                         = 477.96 A
Total Load Calculation:

Total Starting KVA = 0.45+13.33+3.41+120+400
                                = 537.19 KVA
Total Starting Current = 1.93+57.97+14.83+143.2+477.96
                                    = 695.89 A
Total Running KVA    = 0.45+8.33+2.13+26.67+177.78
                                    = 215.36 KVA
Total Running current = 1.93+36.23+9.27+35.8+238.98
                                    = 322.21 A
Size of diesel Generator =(starting KVA*Future Expansion*Average use of equipment)
                                       = (537.19*1.2*0.8)
Size of diesel Generator  = 515.7 KVA.

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