Seaford train air con turns off at lonsdale

[Madbus]

I noticed that every time at a certain point on the Seaford railway line, the train's air conditioners turn off for roughly 1-2 minutes near Lonsdale.
I could only find a brief description of it in this post but didn't go into much detail: https://www.railpage.com.au:80/f-t11377222.htm Would anybody be able to provide more detail?

[boronia]

Possibly, if there is an air gap in the overhead the a/c will shut down as soon as it looses power; it would then have to go through a re-start self-testing cycle when the power comes back on, this could take a minute or so to complete.

Similar thing happens in some Sydney trains with a/c and lighting.

[Lieselta]

Fairly sure Lonsdale is where one of the substations for the overhead electricity is located and it goes through some process on that bit of the line, kind of like how on the London Underground older 1972/3 stock trains will lose lighting when on complex junctions.

[Eagle Eye]

There's a neutral part of overhead line at that location which is a normal part of any electric railway system to help with section isolation (or something like that). While the train passes over that neutral section in only a fraction of a second, as boronia said, the aircon restarts itself and take around 30 seconds before it resumes blowing air. You'd think the Gawler line could have a couple of neutral points due to its length.

I've also been on trains in Brisbane where the lights also switch off briefly after passing over a neutral overhead section, but the lights on our trains aren't affected.

[PD2/20]

The 25kV overhead traction supply is a single phase system. At Lonsdale the line south to Seaford is connected to one phase of the three phase supply from SAPN and the line north to the City is connected tp a second phase to partially even out the loading on the phases. It is also standard practice to install a SVC (static VAR compensator) rail AC substations to further spread the loading. At Londale there is a very short earthed section between back to back section isolators between the two electrical phases. A similar arrangement was installed on the Gawler line just E of Torrens Bridge in the overhead work carried out in July, where connections will be made to the traction sectioning cabin in the fork of the Gawler and Seaford lines. I expect a similar arrangement will be installed at the feeder pointfrom the Kilburn substation.