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Any chance this started as a distribution fault? Could explain the prefault. I remember seeing some strange prefault waveforms and it was due to the underbuilt distribution faulting first. Or perhaps evolving into a transmission to distribution fault?

Another fault location method is to compare the ratio of 3I0 current from each end of the line. That should help account for fault resistance. You would use Synchrowave to get the 3I0 current from each end. Divide one end by the other. Then run intermittent faults in your fault sim program...

How are you finding the best fit with your fault program? Could the fault resistance be the reason your Z0 seems low?

Typical would be 85% reach for Phase distance and 70% reach for Ground distance for Z1.

I model it all in the line constants program that I use as its not much more effort to add the underbuild. But I don't input the mutual impedance between transmission conductors and underbuild into my fault sim program as the distribution system is not modeled. Definitely would recommend...

I checked a random spot on I10 on Street View and it showed 75MPH without a separate speed for trucks.

Single Phase Auto Reclosing I don't think its that common below 500kV. At least that I've seen in the USA.

I'll add another MC Prime annoyance. If you are paging up and your cursor lands in a text box you will enter in it and will have to click outside of the box to continue paging up.

This makes sense. Maybe their policy got lost in translation somewhere.

Nope. What would they do if a significant portion of their lines got hit with lightning? Just leave half their lines out of service? Its normal to go inspect a line that trips to lockout before attempting to re-energize but I've never seen one left de-energized after the problem was found/fixed.

Schweitzer Engineering Laboratories (SEL) has automation controllers. (SEL-2411 for example) They are more utility focused. But their support is amazing and programming them is quite simple.

I've had this one bookmarked for awhile for the next time I needed a automotive connector: https://connectorexperts.com/ Have not used it myself. Otherwise, I just use Deutsch connectors.

I agree with thermionic1, that is the first thing I'd check. Here is the NERC lessons learned overview of the issue. https://www.nerc.com/pa/rrm/ea/Lessons%20Learned%20Document%20Library/LL20130703_Use_Loading_Resistors_when_applying_solid_state_contacts.pdf I've seen it quite of few times...

His 230V supply is single phase and 50hz. He is trying to perform testing from the UK. After installation the source voltage will be the necessary 230V 3 phase 60hz.

I think you will like it after you get used to it a bit.

DC? Like this? https://product.tdk.com/en/search/power/switching-power/high-voltage/info?part_no=802L-50KV-NEG-3P400

The output of the VFD should go direct to the motor. Sounds like you have the contactor in between the motor and the VFD output?

To echo what the others stated, a solid base in math and basic EE concepts will help you for your whole career. Also, a hobby related to engineering is very helpful. Like Arduino/Raspberry Pi , CNC machines, RC cars/planes, etc.

So the new China would allow a freedom movement? I don't think so. I think you would see the "earlier China" again.

I don't remember seeing a policy like that before. Can really only think of one SF6 breaker that I've seen that was an intentional N/O and energized on both sides. Its done all the time at distribution levels but those aren't SF6 breakers.