Characteristic Line Impedance for Line Tuner
Characteristic Line Impedance for Line Tuner
(OP)
I've been asked to provide characteristic line impedance on GE Line tuner's order form. Any ideas as to how do I go about doing this?
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Characteristic Line Impedance for Line Tuner
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Characteristic Line Impedance for Line TunerCharacteristic Line Impedance for Line Tuner(OP)
I've been asked to provide characteristic line impedance on GE Line tuner's order form. Any ideas as to how do I go about doing this?
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RE: Characteristic Line Impedance for Line Tuner
https://www.gegridsolutions.com/app/Resources.aspx...
https://www.gegridsolutions.com/products/brochures...
However the line characteristic impedance Z=SQRT[(R+j*w*L)/(G+j*w*C)]
where R,L,C,G=specific resistance, inductance, capacitance and conductance[ohm/km for instance]
These parameters depend on overhead line constructive details-height, distance between conductors, number of circuits on the same tower, conductor material and diameter, earth resistivity and other parameters, and w=2*pi()*freq.
See for instance:
https://web.ecs.baylor.edu/faculty/grady/_08_ELC43...
RE: Characteristic Line Impedance for Line Tuner
http://romvchvlcomm.pbworks.com/f/C045-P0597.pdf
7anoter4...the link you sent were for line traps. They don't depend on the characteristic line impedance for tuning.
RE: Characteristic Line Impedance for Line Tuner
RE: Characteristic Line Impedance for Line Tuner
RE: Characteristic Line Impedance for Line Tuner
cranky108, how did you get that 300 ohms? I was told to assume the same value by someone else.
Also the information I have is the positive and zero sequence impedances. How do I calculate the characteristic line impedance using the formula in the article mentioned by scottf??
RE: Characteristic Line Impedance for Line Tuner
RE: Characteristic Line Impedance for Line Tuner
RE: Characteristic Line Impedance for Line Tuner
RE: Characteristic Line Impedance for Line Tuner
Hope this help.
RE: Characteristic Line Impedance for Line Tuner
Usually the tuner has a range it can be set at, and if it has the correct range, you can start at some point and do a series of reflected power testing at the center of the frequencies you are intending to operate at.
By adjusting the tuning you should find a dip in the reflected power at the sweet spot.
If you calculate the tuning value, you are almost always off by some, and the tech's will be expecting you to be spot on. You will never hear the end of it.
I'm not sure what I did with the books I had from that class, but likely in my basement somewhere.
RE: Characteristic Line Impedance for Line Tuner
That is correct, the value is just for use as a starting point for the impedance matching transformer. If it can't be tuned with that setting, yo just take it to the next setting up or down depending on tuning results. It's not an exact science for sure. But if you give the factory your best guesstimate of the primary line characteristic impedance, it saves your field techs some time in tuning, as the line tuner is already close to tuned when received.
Most utilities that stock line tuners ask for the IMT to be set at 300 ohms on the primary side.