utility x/r ratio
utility x/r ratio
(OP)
The utility provided the following;
Supply Voltage: 12.48KV,
Short Circuit Data:
L-G Amps: 1869A
P-P Amps: 1782A
3P Amps: 2058A
Z1 = 1.05 +j3.34
Z0 = 1.22 +j4.39
This is on the primary of a pole top transformer that feeds one of our buildings. It is unclear yet, but I think the transformer is a 375kVA 12.48kV - 600V transformer (not sure of configuration). The transformer impedance is around 2.5%.
What does the z1 and z0 represent? If it is the positive and zero sequence impedances, where is the negative sequence impedance? How do I determine the x/r ratio for the 3p and L-g SC currents? How do I translate this to the secondary.
Sorry for the elementary question but this is not what I do in my day to day operations.
Regards,
TULUM
Supply Voltage: 12.48KV,
Short Circuit Data:
L-G Amps: 1869A
P-P Amps: 1782A
3P Amps: 2058A
Z1 = 1.05 +j3.34
Z0 = 1.22 +j4.39
This is on the primary of a pole top transformer that feeds one of our buildings. It is unclear yet, but I think the transformer is a 375kVA 12.48kV - 600V transformer (not sure of configuration). The transformer impedance is around 2.5%.
What does the z1 and z0 represent? If it is the positive and zero sequence impedances, where is the negative sequence impedance? How do I determine the x/r ratio for the 3p and L-g SC currents? How do I translate this to the secondary.
Sorry for the elementary question but this is not what I do in my day to day operations.
Regards,
TULUM






RE: utility x/r ratio
RE: utility x/r ratio
So then the z1 is the positive sequence impedance, and the Z0 is the zero sequence impedance... it has been awhile that is all... I just did not rememeber that the negative sequence impedance is usually a replica of the positive sequence impedance.
Regards,
TULUM
RE: utility x/r ratio
RE: utility x/r ratio
How do you calculate the x value from the transformer nameplate impedance...
TULUM
RE: utility x/r ratio
RE: utility x/r ratio
RE: utility x/r ratio
Calculating X from the transformer %Z will require you to get the actual or assumed X/R ratio for that transformer.