Jakob had pointed out that most of the network was down. (I've been on vacation and hadn't been monitoring.) Apparently stations went down in the last lightning storm (again!), either Fri or Sat. I just:
- found a dead power supply in rne01 and replaced it with the one from rne02. Of course, rne02 is a <repeater> so much of the network is still down.
- reset differential protection on tse13
- reset differential protection on tse11
- reset differential protection on tse09
Of course, this is now <tear down>, so we shouldn't be working to <maintain> the network. Nevertheless, several groups are still running, using this period for post-cals, etc. Eventually, DTU will rework the network for operation after we are gone.
2 Comments
Steve Oncley AUTHOR
Later (~7pm), replaced power supply at rne02 and reset differential protection on tnw10 (both repeater sites) to get even more of the network up.
Steve Oncley AUTHOR
Found that this lightning event was about 18:25 on 17 Jun. Among other things, it killed some of the ridge Tsoils (rne06, rne07, rsw04). These probes now show short circuits between the measurement point and ground (essentially shorts in the internal soil resistor pack). This is confirmed by the resistor pack's datasheet which states: "The LT5400 can withstand up to ±1kV of electrostatic discharge (ESD, human body). To achieve the highest precision matching, the LT5400 is designed without explicit ESD internal protection diodes. ESD beyond this voltage can damage or degrade the device including causing pin-to-pin shorts."
The datasheet goes on to suggest that ESD protection should be added externally.... Maybe we should do this!