EC&M Short Circuit Calculation Guide wrong???
EC&M Short Circuit Calculation Guide wrong???
(OP)
Hi friends!
I recently tracked down an EC&M article discussing the calculation of short circuit calculations using the p.u.
They have the following for fault impedance calculation of:
ZFault=(Zutility+ZT1)||ZMotor1||ZMotor2=(0.0021+j0.083+0.005+j0.07)||(0.49+j13.8)||(29.8+j298)=0.166+j2.817 pu
I added the Zutility and ZT1 together in series and calculated the rest in parallel but get 0.007006 + j0.15125 pu. Am I missing a step here? Can someone point me in the right direction??
The article can be found here:
http ://ecmweb. com/mag/el ectric_sho rtcircuit_ calculatio n_methods/
Thank you in advance!
-EITengineering
I recently tracked down an EC&M article discussing the calculation of short circuit calculations using the p.u.
They have the following for fault impedance calculation of:
ZFault=(Zutility+ZT1)||ZMotor1||ZMotor2=(0.0021+j0.083+0.005+j0.07)||(0.49+j13.8)||(29.8+j298)=0.166+j2.817 pu
I added the Zutility and ZT1 together in series and calculated the rest in parallel but get 0.007006 + j0.15125 pu. Am I missing a step here? Can someone point me in the right direction??
The article can be found here:
http
Thank you in advance!
-EITengineering






RE: EC&M Short Circuit Calculation Guide wrong???
But why use such manual methods, when software is available, even freeware. See http://pp.kpnet.fi/ijl for example.
RE: EC&M Short Circuit Calculation Guide wrong???
Great! now my calculation comes pretty close :)
The reason I want to learn the manual calculation is so i can better understand the results and data input required for the software.
Thanks again for the help!
RE: EC&M Short Circuit Calculation Guide wrong???
Xt = .07 * (100/2) = 3.5
Rt = 3.5/15 = .2333
With this, the resulting values will be almost the same. The EC&M article forgot to change the old pu to new pu values using new base MVA.
http://www.powerqualityworld.com