Can anyone explain the left hand rule?

[bobbo]

The left hand rule told to me, if you got a high line crossing that's exactly perpendicular there will be no induction. Don't get it but it supposedly is true by Nicholas tesla!

And another question which I heard by rumor. If you build a high line and you have a crossing can it somewhat cancel out the circuit to be un useable. Heard from a friend that his son was on. His son built a high line and when they heated it up they found it unusable, because the engineers didn't foresee the crossings canceling the circuit. Have you guys ever heard of such a thing? I know in corridors it gets tight. Can induction effect the other circuits? Thought some high liners might know this? Or some engineer type super high line can extrapolate, don't know what extrapolate means but it sounds good.

[Rob]

There is no canceling out

[BigClive]

I think induction between adjacent lines really relies on large parallel runs of cable exposed to another cables field. If crossing it at right angles the exposed area is very small.

As for the "canceling out" of a circuit by crossing another at right angles. The only reason I could see for the line being unusable is if there was not proper protection from transmission level lines falling onto distribution lines. I get the feeling something has been lost in interpretation here, and possibly warped by a lack of electrical understanding.

[busman]

As one who suffered thru 6 years of Electrical Engineering in college (BS and MS) before I found my calling, I can try. The right-hand rule is generally used as a guide to correlate the direction of the current flow with the direction of the magnetic field (see diagram)



As far as cancellation, that is not how I would describe it. However, the current induced in a conductor is based on a formula that includes the "dot product" of the magnetic field with the wire. See the formula. The dot in the formula is a "dot product" which is just a vector cosine. From Geometry, you may remember that the cosine of 90 degrees is zero, so when the Magnetic Field (B) is perpendicular to the conductor, the dot product is equal to a multiply by zero and there is no induced current. That would only be true for an infinitely long wire. In the real world case, the wire is a loop consisting of the phase and the neutral. However, the perpendicular case has the LEAST induced current because most of the "loop" is far away from the source where the magnetic fields are very weak. That is why parallel has the most induced and perpendicular has he least. Not the best explanation, but close.

As far as right/left hand, that would only matter at a T junction where it induced currents could be made to be out of phase by 180 degrees from the primary current in the wire. Either way, it would just slightly increase of decrease the current depending on which orientation you chose.

Mark

[bobbo]

As one who suffered thru 6 years of Electrical Engineering in college (BS and MS) before I found my calling, I can try. The right-hand rule is generally used as a guide to correlate the direction of the current flow with the direction of the magnetic field (see diagram)



As far as cancellation, that is not how I would describe it. However, the current induced in a conductor is based on a formula that includes the "dot product" of the magnetic field with the wire. See the formula. The dot in the formula is a "dot product" which is just a vector cosine. From Geometry, you may remember that the cosine of 90 degrees is zero, so when the Magnetic Field (B) is perpendicular to the conductor, the dot product is equal to a multiply by zero and there is no induced current. That would only be true for an infinitely long wire. In the real world case, the wire is a loop consisting of the phase and the neutral. However, the perpendicular case has the LEAST induced current because most of the "loop" is far away from the source where the magnetic fields are very weak. That is why parallel has the most induced and perpendicular has he least. Not the best explanation, but close.

As far as right/left hand, that would only matter at a T junction where it induced currents could be made to be out of phase by 180 degrees from the primary current in the wire. Either way, it would just slightly increase of decrease the current depending on which orientation you chose.

Mark

Thank you so much! We need you here!

[bobbo]

Is there such a way that a line can be built. Example 230kv and 500kv where the magnetics would fight each other to cancel. Where the fields are so big on the 500 and would cancel the 230 some how? Not line loss. The 500 would screw up the sine wave of the 230. I heard the story didn't know if it was true, just wanted to ask.

[busman]

Thank you so much! We need you here!

I never thought I would hear a lineman say that about a Sparky, but thanks. I figure it's the least I can do for all the help the Linemen on this forum have provided me.

Mark